add backoff, add simple pool, clean listeners

build.gradle

@@ -37,6 +37,7 @@ dependencies {
     compile "org.xbib:net-url:${project.property('xbib-net-url.version')}"
     compile "io.netty:netty-codec-http2:${project.property('netty.version')}"
     compile "io.netty:netty-handler-proxy:${project.property('netty.version')}"
+    testCompile "io.netty:netty-transport-native-epoll:${project.property('netty.version')}"
     testCompile "io.netty:netty-tcnative-boringssl-static:${project.property('tcnative.version')}"
     testCompile "org.conscrypt:conscrypt-openjdk-uber:${project.property('conscrypt.version')}"
     testCompile "junit:junit:${project.property('junit.version')}"

gradle.properties

@@ -1,8 +1,8 @@
 group = org.xbib
 name = netty-http-client
-version = 4.1.19.1
+version = 4.1.16.0
 
-netty.version = 4.1.19.Final
+netty.version = 4.1.16.Final
 tcnative.version = 2.0.7.Final
 conscrypt.version = 1.0.1
 xbib-net-url.version = 1.1.0

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Sun Feb 25 12:39:15 CET 2018
+#Fri Mar 02 19:15:04 CET 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-rc-1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip

src/main/java/org/xbib/netty/http/client/Client.java

@@ -18,15 +18,21 @@ import org.xbib.netty.http.client.handler.http1.HttpResponseHandler;
 import org.xbib.netty.http.client.handler.http2.Http2ChannelInitializer;
 import org.xbib.netty.http.client.handler.http2.Http2ResponseHandler;
 import org.xbib.netty.http.client.handler.http2.Http2SettingsHandler;
+import org.xbib.netty.http.client.pool.Pool;
+import org.xbib.netty.http.client.pool.SimpleChannelPool;
 import org.xbib.netty.http.client.transport.Http2Transport;
 import org.xbib.netty.http.client.transport.HttpTransport;
 import org.xbib.netty.http.client.transport.Transport;
 import org.xbib.netty.http.client.util.NetworkUtils;
 
+import javax.net.ssl.TrustManagerFactory;
+import java.io.IOException;
+import java.security.KeyStoreException;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.ThreadFactory;
 import java.util.function.Function;
 import java.util.logging.Level;
@@ -62,6 +68,8 @@ public final class Client {
 
     private TransportListener transportListener;
 
+    private Pool<Channel> pool;
+
     public Client() {
         this(new ClientConfig());
     }
@@ -74,6 +82,7 @@ public final class Client {
                   EventLoopGroup eventLoopGroup, Class<? extends SocketChannel> socketChannelClass) {
         Objects.requireNonNull(clientConfig);
         this.clientConfig = clientConfig;
+        initializeTrustManagerFactory(clientConfig);
         this.byteBufAllocator = byteBufAllocator != null ?
                 byteBufAllocator : PooledByteBufAllocator.DEFAULT;
         this.eventLoopGroup = eventLoopGroup != null ?
@@ -94,6 +103,22 @@ public final class Client {
         this.http2SettingsHandler = new Http2SettingsHandler();
         this.http2ResponseHandler = new Http2ResponseHandler();
         this.transports = new CopyOnWriteArrayList<>();
+        List<HttpAddress> nodes = clientConfig.getNodes();
+        if (!nodes.isEmpty()) {
+            Integer limit = clientConfig.getNodeConnectionLimit();
+            if (limit == null || limit > nodes.size()) {
+                limit = nodes.size();
+            }
+            if (limit < 1) {
+                limit = 1;
+            }
+            Semaphore semaphore = new Semaphore(limit);
+            Integer retries = clientConfig.getRetriesPerNode();
+            if (retries == null || retries < 0) {
+                retries = 0;
+            }
+            this.pool = new SimpleChannelPool<>(semaphore, nodes, bootstrap, null, retries);
+        }
     }
 
     public static ClientBuilder builder() {
@@ -140,23 +165,28 @@ public final class Client {
     public Channel newChannel(HttpAddress httpAddress) throws InterruptedException {
         HttpVersion httpVersion = httpAddress.getVersion();
         ChannelInitializer<SocketChannel> initializer;
+        Channel channel;
         if (httpVersion.majorVersion() < 2) {
             initializer = new HttpChannelInitializer(clientConfig, httpAddress, httpResponseHandler);
+            channel = bootstrap.handler(initializer)
+                    .connect(httpAddress.getInetSocketAddress()).sync().await().channel();
         } else {
-            initializer = new Http2ChannelInitializer(clientConfig, httpAddress, http2SettingsHandler, http2ResponseHandler);
+            initializer = new Http2ChannelInitializer(clientConfig, httpAddress,
-        }
+                    http2SettingsHandler, http2ResponseHandler);
-        return bootstrap.handler(initializer)
+            channel = bootstrap.handler(initializer)
                     .connect(httpAddress.getInetSocketAddress()).sync().await().channel();
         }
+        return channel;
+    }
 
-    public Transport execute(Request request) {
+    public Transport execute(Request request) throws IOException {
-        Transport nextTransport = newTransport(HttpAddress.of(request));
+        Transport transport = newTransport(HttpAddress.of(request));
-        nextTransport.execute(request);
+        transport.execute(request);
-        return nextTransport;
+        return transport;
     }
 
     public <T> CompletableFuture<T> execute(Request request,
-                                            Function<FullHttpResponse, T> supplier) {
+                                            Function<FullHttpResponse, T> supplier) throws IOException {
         return newTransport(HttpAddress.of(request)).execute(request, supplier);
     }
 
@@ -165,19 +195,19 @@ public final class Client {
      * @param transport the previous transport
      * @param request the new request for continuing the request.
      */
-    public void continuation(Transport transport, Request request) {
+    public void continuation(Transport transport, Request request) throws IOException {
         Transport nextTransport = newTransport(HttpAddress.of(request));
-        nextTransport.setResponseListener(transport.getResponseListener());
-        nextTransport.setExceptionListener(transport.getExceptionListener());
-        nextTransport.setHeadersListener(transport.getHeadersListener());
-        nextTransport.setCookieListener(transport.getCookieListener());
-        nextTransport.setPushListener(transport.getPushListener());
         nextTransport.setCookieBox(transport.getCookieBox());
         nextTransport.execute(request);
         nextTransport.get();
         close(nextTransport);
     }
 
+    public void retry(Transport transport, Request request) throws IOException {
+        transport.execute(request);
+        transport.get();
+        close(transport);
+    }
 
     public Transport prepareRequest(Request request) {
         return newTransport(HttpAddress.of(request));
@@ -206,6 +236,21 @@ public final class Client {
         shutdown();
     }
 
+    /**
+     * Initialize trust manager factory once per client lifecycle.
+     * @param clientConfig the client config
+     */
+    private static void initializeTrustManagerFactory(ClientConfig clientConfig) {
+        TrustManagerFactory trustManagerFactory = clientConfig.getTrustManagerFactory();
+        if (trustManagerFactory != null) {
+            try {
+                trustManagerFactory.init(clientConfig.getTrustManagerKeyStore());
+            } catch (KeyStoreException e) {
+                logger.log(Level.WARNING, e.getMessage(), e);
+            }
+        }
+    }
+
     public interface TransportListener {
 
         void onOpen(Transport transport);

src/main/java/org/xbib/netty/http/client/ClientConfig.java

@@ -3,14 +3,14 @@ package org.xbib.netty.http.client;
 import io.netty.handler.codec.http2.Http2SecurityUtil;
 import io.netty.handler.proxy.HttpProxyHandler;
 import io.netty.handler.ssl.CipherSuiteFilter;
-import io.netty.handler.ssl.OpenSsl;
 import io.netty.handler.ssl.SslProvider;
 import io.netty.handler.ssl.SupportedCipherSuiteFilter;
-import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 
 import javax.net.ssl.TrustManagerFactory;
 import java.io.InputStream;
+import java.security.KeyStore;
 import java.security.Provider;
+import java.util.List;
 
 public class ClientConfig {
 
@@ -110,11 +110,6 @@ public class ClientConfig {
          */
         CipherSuiteFilter CIPHER_SUITE_FILTER = SupportedCipherSuiteFilter.INSTANCE;
 
-        /**
-         * Default trust manager factory.
-         */
-        TrustManagerFactory TRUST_MANAGER_FACTORY = InsecureTrustManagerFactory.INSTANCE;
-
         boolean USE_SERVER_NAME_IDENTIFICATION = true;
 
         /**
@@ -123,6 +118,20 @@ public class ClientConfig {
         ClientAuthMode SSL_CLIENT_AUTH_MODE = ClientAuthMode.NONE;
     }
 
+    private static TrustManagerFactory TRUST_MANAGER_FACTORY;
+
+    static {
+        try {
+            TRUST_MANAGER_FACTORY = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
+                    //InsecureTrustManagerFactory.INSTANCE;
+            //TRUST_MANAGER_FACTORY.init((KeyStore) null);
+            // java.lang.IllegalStateException: TrustManagerFactoryImpl is not initialized
+                    //TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
+        } catch (Exception e) {
+            TRUST_MANAGER_FACTORY = null;
+        }
+    }
+
     private boolean debug = Defaults.DEBUG;
 
     /**
@@ -165,7 +174,9 @@ public class ClientConfig {
 
     private CipherSuiteFilter cipherSuiteFilter = Defaults.CIPHER_SUITE_FILTER;
 
-    private TrustManagerFactory trustManagerFactory = Defaults.TRUST_MANAGER_FACTORY;
+    private TrustManagerFactory trustManagerFactory = TRUST_MANAGER_FACTORY;
+
+    private KeyStore trustManagerKeyStore = null;
 
     private boolean serverNameIdentification = Defaults.USE_SERVER_NAME_IDENTIFICATION;
 
@@ -179,6 +190,12 @@ public class ClientConfig {
 
     private HttpProxyHandler httpProxyHandler;
 
+    private List<HttpAddress> nodes;
+
+    private Integer nodeConnectionLimit;
+
+    private Integer retriesPerNode;
+
     public ClientConfig setDebug(boolean debug) {
         this.debug = debug;
         return this;
@@ -370,15 +387,6 @@ public class ClientConfig {
         return cipherSuiteFilter;
     }
 
-    public ClientConfig setTrustManagerFactory(TrustManagerFactory trustManagerFactory) {
-        this.trustManagerFactory = trustManagerFactory;
-        return this;
-    }
-
-    public TrustManagerFactory getTrustManagerFactory() {
-        return trustManagerFactory;
-    }
-
     public ClientConfig setKeyCert(InputStream keyCertChainInputStream, InputStream keyInputStream) {
         this.keyCertChainInputStream = keyCertChainInputStream;
         this.keyInputStream = keyInputStream;
@@ -423,6 +431,24 @@ public class ClientConfig {
         return clientAuthMode;
     }
 
+    public ClientConfig setTrustManagerFactory(TrustManagerFactory trustManagerFactory) {
+        this.trustManagerFactory = trustManagerFactory;
+        return this;
+    }
+
+    public TrustManagerFactory getTrustManagerFactory() {
+        return trustManagerFactory;
+    }
+
+    public ClientConfig setTrustManagerKeyStore(KeyStore trustManagerKeyStore) {
+        this.trustManagerKeyStore = trustManagerKeyStore;
+        return this;
+    }
+
+    public KeyStore getTrustManagerKeyStore() {
+        return trustManagerKeyStore;
+    }
+
     public ClientConfig setHttpProxyHandler(HttpProxyHandler httpProxyHandler) {
         this.httpProxyHandler = httpProxyHandler;
         return this;
@@ -432,6 +458,33 @@ public class ClientConfig {
         return httpProxyHandler;
     }
 
+    public ClientConfig setNodes(List<HttpAddress> nodes) {
+        this.nodes = nodes;
+        return this;
+    }
+
+    public List<HttpAddress> getNodes() {
+        return nodes;
+    }
+
+    public ClientConfig setNodeConnectionLimit(Integer nodeConnectionLimit) {
+        this.nodeConnectionLimit = nodeConnectionLimit;
+        return this;
+    }
+
+    public Integer getNodeConnectionLimit() {
+        return nodeConnectionLimit;
+    }
+
+    public ClientConfig setRetriesPerNode(Integer retriesPerNode) {
+        this.retriesPerNode = retriesPerNode;
+        return this;
+    }
+
+    public Integer getRetriesPerNode() {
+        return retriesPerNode;
+    }
+
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();

src/main/java/org/xbib/netty/http/client/HttpAddress.java

@@ -2,13 +2,14 @@ package org.xbib.netty.http.client;
 
 import io.netty.handler.codec.http.HttpVersion;
 import org.xbib.net.URL;
+import org.xbib.netty.http.client.pool.PoolKey;
 
 import java.net.InetSocketAddress;
 
 /**
  * A handle for host, port, HTTP version, secure transport flag of a channel for HTTP.
  */
-public class HttpAddress {
+public class HttpAddress implements PoolKey {
 
     private static final HttpVersion HTTP_2_0 = HttpVersion.valueOf("HTTP/2.0");
 

src/main/java/org/xbib/netty/http/client/Request.java

@@ -8,9 +8,7 @@ import io.netty.handler.codec.http.cookie.Cookie;
 
 import org.xbib.net.URL;
 import org.xbib.netty.http.client.listener.CookieListener;
-import org.xbib.netty.http.client.listener.ExceptionListener;
 import org.xbib.netty.http.client.listener.HttpHeadersListener;
-import org.xbib.netty.http.client.listener.HttpPushListener;
 import org.xbib.netty.http.client.listener.HttpResponseListener;
 
 import java.nio.charset.StandardCharsets;
@@ -45,14 +43,10 @@ public class Request {
 
     private HttpResponseListener responseListener;
 
-    private ExceptionListener exceptionListener;
-
     private HttpHeadersListener headersListener;
 
     private CookieListener cookieListener;
 
-    private HttpPushListener pushListener;
-
     Request(URL url, HttpVersion httpVersion, HttpMethod httpMethod,
             HttpHeaders headers, Collection<Cookie> cookies,
             String uri, ByteBuf content,
@@ -120,12 +114,13 @@ public class Request {
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
-        sb.append("base=").append(base).append(',')
+        sb.append("Request[base='").append(base)
-                .append("version=").append(httpVersion).append(',')
+                .append("',version=").append(httpVersion)
-                .append("method=").append(httpMethod).append(',')
+                .append(",method=").append(httpMethod)
-                .append("relativeUri=").append(uri).append(',')
+                .append(",uri=").append(uri)
-                .append("headers=").append(headers).append(',')
+                .append(",headers=").append(headers.entries())
-                .append("content=").append(content != null ? content.copy(0,16).toString(StandardCharsets.UTF_8) : "");
+                .append(",content=").append(content != null ? content.copy(0,16).toString(StandardCharsets.UTF_8) : "")
+                .append("]");
         return sb.toString();
     }
 
@@ -156,24 +151,6 @@ public class Request {
         return responseListener;
     }
 
-    public Request setExceptionListener(ExceptionListener exceptionListener) {
-        this.exceptionListener = exceptionListener;
-        return this;
-    }
-
-    public ExceptionListener getExceptionListener() {
-        return exceptionListener;
-    }
-
-    public Request setPushListener(HttpPushListener httpPushListener) {
-        this.pushListener = httpPushListener;
-        return this;
-    }
-
-    public HttpPushListener getPushListener() {
-        return pushListener;
-    }
-
     public static RequestBuilder get() {
         return builder(HttpMethod.GET);
     }

src/main/java/org/xbib/netty/http/client/RequestBuilder.java

@@ -13,6 +13,7 @@ import io.netty.handler.codec.http.QueryStringEncoder;
 import io.netty.handler.codec.http.cookie.Cookie;
 import io.netty.handler.codec.http2.HttpConversionUtil;
 import io.netty.util.AsciiString;
+import org.xbib.net.QueryParameters;
 import org.xbib.net.URL;
 import org.xbib.net.URLSyntaxException;
 
@@ -67,7 +68,9 @@ public class RequestBuilder {
 
     private URL url;
 
-    private QueryStringEncoder queryStringEncoder;
+    private String uri;
+
+    private QueryParameters queryParameters;
 
     private ByteBuf content;
 
@@ -90,6 +93,7 @@ public class RequestBuilder {
         headers = new DefaultHttpHeaders();
         removeHeaders = new ArrayList<>();
         cookies = new HashSet<>();
+        queryParameters = new QueryParameters();
     }
 
     public RequestBuilder setMethod(HttpMethod httpMethod) {
@@ -97,12 +101,12 @@ public class RequestBuilder {
         return this;
     }
 
-    public RequestBuilder setHttp1() {
+    public RequestBuilder enableHttp1() {
         this.httpVersion = HttpVersion.HTTP_1_1;
         return this;
     }
 
-    public RequestBuilder setHttp2() {
+    public RequestBuilder enableHttp2() {
         this.httpVersion = HTTP_2_0;
         return this;
     }
@@ -122,32 +126,27 @@ public class RequestBuilder {
         return this;
     }
 
-    public RequestBuilder setURL(String url) {
+    public RequestBuilder remoteAddress(HttpAddress httpAddress) {
-        return setURL(URL.from(url));
+        this.url = URL.builder()
-    }
+                .scheme(httpAddress.isSecure() ? "https" : "http")
-
+                .host(httpAddress.getInetSocketAddress().getHostString())
-    public RequestBuilder setURL(URL url) {
+                .port(httpAddress.getInetSocketAddress().getPort())
-        this.url = url;
+                .build();
-        QueryStringDecoder queryStringDecoder = new QueryStringDecoder(URI.create(url.toString()), StandardCharsets.UTF_8);
+        this.httpVersion = httpAddress.getVersion();
-        this.queryStringEncoder = new QueryStringEncoder(queryStringDecoder.path());
-        for (Map.Entry<String, List<String>> entry : queryStringDecoder.parameters().entrySet()) {
-            for (String value : entry.getValue()) {
-                queryStringEncoder.addParam(entry.getKey(), value);
-            }
-        }
         return this;
     }
 
-    public RequestBuilder path(String path) {
+    public RequestBuilder url(String url) {
-        if (this.url != null) {
+        return url(URL.from(url));
-            try {
-                setURL(URL.base(url).resolve(path).toString());
-            } catch (URLSyntaxException e) {
-                throw new IllegalArgumentException(e);
     }
-        } else {
+
-            setURL(path);
+    public RequestBuilder url(URL url) {
+        this.url = url;
+        return this;
     }
+
+    public RequestBuilder uri(String uri) {
+        this.uri = uri;
         return this;
     }
 
@@ -171,9 +170,9 @@ public class RequestBuilder {
         return this;
     }
 
-    public RequestBuilder addParam(String name, String value) {
+    public RequestBuilder addParameter(String name, String value) {
-        if (queryStringEncoder != null) {
+        if (queryParameters != null) {
-            queryStringEncoder.addParam(name, value);
+            queryParameters.add(name, value);
         }
         return this;
     }
@@ -213,11 +212,6 @@ public class RequestBuilder {
         return this;
     }
 
-    public RequestBuilder setContent(ByteBuf byteBuf) {
-        this.content = byteBuf;
-        return this;
-    }
-
     public RequestBuilder text(String text) {
         content(text, HttpHeaderValues.TEXT_PLAIN);
         return this;
@@ -233,6 +227,11 @@ public class RequestBuilder {
         return this;
     }
 
+    public RequestBuilder content(ByteBuf byteBuf) {
+        this.content = byteBuf;
+        return this;
+    }
+
     public RequestBuilder content(CharSequence charSequence, String contentType) {
         content(charSequence.toString().getBytes(StandardCharsets.UTF_8), AsciiString.of(contentType));
         return this;
@@ -253,8 +252,38 @@ public class RequestBuilder {
             throw new IllegalStateException("URL not set");
         }
         if (url.getHost() == null) {
-            throw new IllegalStateException("URL host not set: " + url);
+            throw new IllegalStateException("host in URL not defined: " + url);
         }
+        if (uri != null) {
+            if (this.url != null) {
+                try {
+                    url = URL.base(url).resolve(uri);
+                } catch (URLSyntaxException e) {
+                    throw new IllegalArgumentException(e);
+                }
+            } else {
+                url(uri);
+            }
+        }
+        // add explicit parameters to URL
+        queryParameters.forEach(param -> url.getQueryParams().add(param));
+        // let Netty's query string decoder/encoder work over the URL to add paramters given implicitly in url()
+        QueryStringDecoder queryStringDecoder = new QueryStringDecoder(URI.create(url.toString()), StandardCharsets.UTF_8);
+        QueryStringEncoder queryStringEncoder = new QueryStringEncoder(queryStringDecoder.path());
+        for (Map.Entry<String, List<String>> entry : queryStringDecoder.parameters().entrySet()) {
+            for (String value : entry.getValue()) {
+                queryStringEncoder.addParam(entry.getKey(), value);
+            }
+        }
+        // build uri from QueryStringDecoder
+        StringBuilder sb = new StringBuilder();
+        String pathAndQuery = queryStringEncoder.toString();
+        sb.append(pathAndQuery.isEmpty() ? "/" : pathAndQuery);
+        String ref = url.getFragment();
+        if (ref != null && !ref.isEmpty()) {
+            sb.append('#').append(ref);
+        }
+        String uri = sb.toString();
         DefaultHttpHeaders validatedHeaders = new DefaultHttpHeaders(true);
         validatedHeaders.set(headers);
         String scheme = url.getScheme();
@@ -290,23 +319,10 @@ public class RequestBuilder {
         for (String headerName : removeHeaders) {
             validatedHeaders.remove(headerName);
         }
-        // create origin form from query string encoder
-        String uri = toOriginForm();
         return new Request(url, httpVersion, httpMethod, validatedHeaders, cookies, uri, content,
                 timeout, followRedirect, maxRedirects, 0);
     }
 
-    private String toOriginForm() {
-        StringBuilder sb = new StringBuilder();
-        String pathAndQuery = queryStringEncoder.toString();
-        sb.append(pathAndQuery.isEmpty() ? "/" : pathAndQuery);
-        String ref = url.getFragment();
-        if (ref != null && !ref.isEmpty()) {
-            sb.append('#').append(ref);
-        }
-        return sb.toString();
-    }
-
     private void addHeader(AsciiString name, Object value) {
         if (!headers.contains(name)) {
             headers.add(name, value);

src/main/java/org/xbib/netty/http/client/handler/http1/HttpChannelInitializer.java

@@ -9,7 +9,6 @@ import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.SslHandler;
-import io.netty.handler.stream.ChunkedWriteHandler;
 import org.xbib.netty.http.client.ClientConfig;
 import org.xbib.netty.http.client.HttpAddress;
 import org.xbib.netty.http.client.handler.TrafficLoggingHandler;
@@ -51,11 +50,15 @@ public class HttpChannelInitializer extends ChannelInitializer<SocketChannel> {
         try {
             SslContextBuilder sslContextBuilder = SslContextBuilder.forClient()
                     .sslProvider(clientConfig.getSslProvider())
-                    .sslContextProvider(clientConfig.getSslContextProvider())
                     .keyManager(clientConfig.getKeyCertChainInputStream(), clientConfig.getKeyInputStream(),
                             clientConfig.getKeyPassword())
-                    .ciphers(clientConfig.getCiphers(), clientConfig.getCipherSuiteFilter())
+                    .ciphers(clientConfig.getCiphers(), clientConfig.getCipherSuiteFilter());
-                    .trustManager(clientConfig.getTrustManagerFactory());
+            if (clientConfig.getSslContextProvider() != null) {
+                sslContextBuilder.sslContextProvider(clientConfig.getSslContextProvider());
+            }
+            if (clientConfig.getTrustManagerFactory() != null) {
+                sslContextBuilder.trustManager(clientConfig.getTrustManagerFactory());
+            }
             SslContext sslContext = sslContextBuilder.build();
             SslHandler sslHandler = sslContext.newHandler(ch.alloc());
             SSLEngine engine = sslHandler.engine();

src/main/java/org/xbib/netty/http/client/handler/http2/Http2ChannelInitializer.java

@@ -4,7 +4,7 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.handler.codec.http2.DefaultHttp2Connection;
-import io.netty.handler.codec.http2.DelegatingDecompressorFrameListener;
+import io.netty.handler.codec.http2.Http2Connection;
 import io.netty.handler.codec.http2.Http2ConnectionHandler;
 import io.netty.handler.codec.http2.Http2FrameLogger;
 import io.netty.handler.codec.http2.Http2SecurityUtil;
@@ -18,7 +18,6 @@ import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.SslHandler;
 import io.netty.handler.ssl.SupportedCipherSuiteFilter;
-import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 import org.xbib.netty.http.client.ClientConfig;
 import org.xbib.netty.http.client.HttpAddress;
 
@@ -60,10 +59,10 @@ public class Http2ChannelInitializer extends ChannelInitializer<SocketChannel> {
      */
     @Override
     protected void initChannel(SocketChannel ch) {
-        DefaultHttp2Connection http2Connection = new DefaultHttp2Connection(false);
+        Http2Connection http2Connection = new DefaultHttp2Connection(false);
         HttpToHttp2ConnectionHandlerBuilder http2ConnectionHandlerBuilder = new HttpToHttp2ConnectionHandlerBuilder()
                 .connection(http2Connection)
-                .frameListener(new DelegatingDecompressorFrameListener(http2Connection,
+                .frameListener(new Http2PushPromiseHandler(http2Connection,
                         new InboundHttp2ToHttpAdapterBuilder(http2Connection)
                                 .maxContentLength(clientConfig.getMaxContentLength())
                                 .propagateSettings(true)
@@ -75,7 +74,6 @@ public class Http2ChannelInitializer extends ChannelInitializer<SocketChannel> {
         try {
             SslContextBuilder sslContextBuilder = SslContextBuilder.forClient()
                     .sslProvider(clientConfig.getSslProvider())
-                    .trustManager(InsecureTrustManagerFactory.INSTANCE)
                     .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
                     .applicationProtocolConfig(new ApplicationProtocolConfig(
                             ApplicationProtocolConfig.Protocol.ALPN,
@@ -85,6 +83,9 @@ public class Http2ChannelInitializer extends ChannelInitializer<SocketChannel> {
             if (clientConfig.getSslContextProvider() != null) {
                 sslContextBuilder.sslContextProvider(clientConfig.getSslContextProvider());
             }
+            if (clientConfig.getTrustManagerFactory() != null) {
+                sslContextBuilder.trustManager(clientConfig.getTrustManagerFactory());
+            }
             SslContext sslContext = sslContextBuilder.build();
             SslHandler sslHandler = sslContext.newHandler(ch.alloc());
             SSLEngine engine = sslHandler.engine();

src/main/java/org/xbib/netty/http/client/handler/http2/Http2PushPromiseHandler.java

@@ -0,0 +1,24 @@
+package org.xbib.netty.http.client.handler.http2;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.http2.DelegatingDecompressorFrameListener;
+import io.netty.handler.codec.http2.Http2Connection;
+import io.netty.handler.codec.http2.Http2Exception;
+import io.netty.handler.codec.http2.Http2FrameListener;
+import io.netty.handler.codec.http2.Http2Headers;
+import org.xbib.netty.http.client.transport.Transport;
+
+public class Http2PushPromiseHandler extends DelegatingDecompressorFrameListener {
+
+    public Http2PushPromiseHandler(Http2Connection connection, Http2FrameListener listener) {
+        super(connection, listener);
+    }
+
+    @Override
+    public void onPushPromiseRead(ChannelHandlerContext ctx, int streamId, int promisedStreamId,
+                                  Http2Headers headers, int padding) throws Http2Exception {
+        super.onPushPromiseRead(ctx, streamId, promisedStreamId, headers, padding);
+        Transport transport = ctx.channel().attr(Transport.TRANSPORT_ATTRIBUTE_KEY).get();
+        transport.pushPromiseReceived(streamId, promisedStreamId, headers);
+    }
+}

src/main/java/org/xbib/netty/http/client/handler/http2/Http2ResponseHandler.java

@@ -20,11 +20,6 @@ public class Http2ResponseHandler extends SimpleChannelInboundHandler<FullHttpRe
         transport.responseReceived(streamId, httpResponse);
     }
 
-    @Override
-    public void channelReadComplete(ChannelHandlerContext ctx)  {
-        // do nothing
-    }
-
     @Override
     public void channelInactive(ChannelHandlerContext ctx)  {
         ctx.fireChannelInactive();

src/main/java/org/xbib/netty/http/client/listener/HttpPushListener.java

@@ -1,10 +0,0 @@
-package org.xbib.netty.http.client.listener;
-
-import io.netty.handler.codec.http.FullHttpResponse;
-import io.netty.handler.codec.http2.Http2Headers;
-
-@FunctionalInterface
-public interface HttpPushListener {
-
-    void onPushReceived(Http2Headers headers, FullHttpResponse fullHttpResponse);
-}

src/main/java/org/xbib/netty/http/client/pool/ChannelPool.java

@@ -1,23 +0,0 @@
-package org.xbib.netty.http.client.pool;
-
-import io.netty.channel.Channel;
-import io.netty.util.AttributeKey;
-
-import java.io.Closeable;
-import java.net.ConnectException;
-import java.util.List;
-
-public interface ChannelPool extends Closeable {
-
-	AttributeKey<String> NODE_ATTRIBUTE_KEY = AttributeKey.valueOf("node");
-
-	void prepare(int count) throws ConnectException;
-
-	Channel lease() throws ConnectException;
-	
-	int lease(List<Channel> channels, int maxCount) throws ConnectException;
-
-	void release(Channel channel);
-	
-	void release(List<Channel> channels);
-}

src/main/java/org/xbib/netty/http/client/pool/Pool.java

@@ -0,0 +1,17 @@
+package org.xbib.netty.http.client.pool;
+
+import java.io.Closeable;
+import java.util.List;
+
+public interface Pool<T> extends Closeable {
+
+    void prepare(int count) throws Exception;
+
+    T acquire() throws Exception;
+
+    int acquire(List<T> list, int maxCount) throws Exception;
+
+    void release(T t) throws Exception;
+
+    void release(List<T> list) throws Exception;
+}

src/main/java/org/xbib/netty/http/client/pool/PoolKey.java

@@ -0,0 +1,8 @@
+package org.xbib.netty.http.client.pool;
+
+import java.net.InetSocketAddress;
+
+public interface PoolKey {
+
+    InetSocketAddress getInetSocketAddress();
+}

src/main/java/org/xbib/netty/http/client/pool/SimpleChannelPool.java

@@ -6,9 +6,9 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.pool.ChannelPoolHandler;
+import io.netty.util.AttributeKey;
 
 import java.net.ConnectException;
-import java.net.InetSocketAddress;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -19,73 +19,74 @@ import java.util.concurrent.Semaphore;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
-
+public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
-public class SimpleChannelPool implements ChannelPool {
 
     private static final Logger logger = Logger.getLogger(SimpleChannelPool.class.getName());
 
     private final Semaphore semaphore;
 
-    private final List<String> nodes;
+    private final ChannelPoolHandler channelPoolhandler;
+
+    private final List<K> nodes;
 
     private final int numberOfNodes;
 
     private final int retriesPerNode;
 
-    private final Map<String, Bootstrap> bootstraps;
+    private final Map<K, Bootstrap> bootstraps;
 
-    private final Map<String, List<Channel>> channels;
+    private final Map<K, List<Channel>> channels;
 
-    private final Map<String, Queue<Channel>> availableChannels;
+    private final Map<K, Queue<Channel>> availableChannels;
 
-    private final Map<String, Integer> counts;
+    private final Map<K, Integer> counts;
 
-    private final Map<String, Integer> failedCounts;
+    private final Map<K, Integer> failedCounts;
 
-    private final Lock lock = new ReentrantLock();
+    private final Lock lock;
+
+    private final AttributeKey<K> attributeKey;
 
     /**
-     * @param semaphore the throttle for the concurrency level control
+     * @param semaphore the concurrency level
      * @param nodes the endpoint nodes, any element may contain the port (followed after ":")
      *             to override the defaultPort argument
      * @param bootstrap bootstrap instance
      * @param channelPoolHandler channel pool handler being notified upon new connection is created
-     * @param defaultPort default port used to connect (any node address from the nodes set may override this)
      * @param retriesPerNode the max count of the subsequent connection failures to the node before
-     *                       the node will be excluded from the pool, 0 means no limit
+     *                       the node will be excluded from the pool. If set to 0, the value is ignored.
      */
-    public SimpleChannelPool(Semaphore semaphore, List<String> nodes, Bootstrap bootstrap,
+    public SimpleChannelPool(Semaphore semaphore, List<K> nodes, Bootstrap bootstrap,
-                             ChannelPoolHandler channelPoolHandler, int defaultPort, int retriesPerNode) {
+                             ChannelPoolHandler channelPoolHandler, int retriesPerNode) {
         this.semaphore = semaphore;
+        this.channelPoolhandler = channelPoolHandler;
+        this.nodes = nodes;
+        this.retriesPerNode = retriesPerNode;
+        this.lock = new ReentrantLock();
+        this.attributeKey = AttributeKey.valueOf("poolKey");
         if (nodes == null || nodes.isEmpty()) {
             throw new IllegalArgumentException("empty nodes array argument");
         }
-        this.nodes = nodes;
-        this.retriesPerNode = retriesPerNode;
         this.numberOfNodes = nodes.size();
         bootstraps = new HashMap<>(numberOfNodes);
         channels = new HashMap<>(numberOfNodes);
         availableChannels = new HashMap<>(numberOfNodes);
         counts = new HashMap<>(numberOfNodes);
         failedCounts = new HashMap<>(numberOfNodes);
-        for (String node : nodes) {
+        for (K node : nodes) {
-            InetSocketAddress nodeAddr;
+            bootstraps.put(node, bootstrap.clone().remoteAddress(node.getInetSocketAddress())
-            if (node.contains(":")) {
-                String addrParts[] = node.split(":");
-                nodeAddr = new InetSocketAddress(addrParts[0], Integer.parseInt(addrParts[1]));
-            } else {
-                nodeAddr = new InetSocketAddress(node, defaultPort);
-            }
-            bootstraps.put(node, bootstrap.clone().remoteAddress(nodeAddr)
                 .handler(new ChannelInitializer<Channel>() {
                     @Override
-                                        protected void initChannel(Channel conn) throws Exception {
+                    protected void initChannel(Channel channel) throws Exception {
-                                            if(!conn.eventLoop().inEventLoop()) {
+                        if(!channel.eventLoop().inEventLoop()) {
-                                                throw new AssertionError();
+                            throw new IllegalStateException();
+                        }
+                        if (channelPoolHandler != null) {
+                            channelPoolHandler.channelCreated(channel);
                         }
-                                            channelPoolHandler.channelCreated(conn);
                     }
                 }));
             availableChannels.put(node, new ConcurrentLinkedQueue<>());
@@ -99,10 +100,10 @@ public class SimpleChannelPool implements ChannelPool {
         if (count > 0) {
             for (int i = 0; i < count; i ++) {
                 Channel channel = connectToAnyNode();
-                if(channel == null) {
+                if (channel == null) {
-                    throw new ConnectException("Failed to pre-create the connections to the target nodes");
+                    throw new ConnectException("failed to prepare the connections");
                 }
-                String nodeAddr = channel.attr(NODE_ATTRIBUTE_KEY).get();
+                K nodeAddr = channel.attr(attributeKey).get();
                 if (channel.isActive()) {
                     Queue<Channel> channelQueue = availableChannels.get(nodeAddr);
                     if (channelQueue != null) {
@@ -112,49 +113,117 @@ public class SimpleChannelPool implements ChannelPool {
                     channel.close();
                 }
             }
-            logger.info("prepared " + count + " connections");
+            logger.log(Level.FINE,"prepared " + count + " connections");
         } else {
             throw new IllegalArgumentException("Connection count should be > 0, but got " + count);
         }
     }
 
-    private class CloseChannelListener implements ChannelFutureListener {
+    @Override
-
+    public Channel acquire() throws Exception {
-        private final String nodeAddr;
+        Channel channel = null;
-        private final Channel conn;
+        if (semaphore.tryAcquire()) {
-
+            if ((channel = poll()) == null) {
-        private CloseChannelListener(String nodeAddr, Channel conn) {
+                channel = connectToAnyNode();
-            this.nodeAddr = nodeAddr;
+            }
-            this.conn = conn;
+            if (channel == null) {
+                semaphore.release();
+                throw new ConnectException();
+            }
+        }
+        if (channelPoolhandler != null) {
+            channelPoolhandler.channelAcquired(channel);
+        }
+        return channel;
     }
 
     @Override
-        public void operationComplete(ChannelFuture future) {
+    public int acquire(List<Channel> channels, int maxCount) throws Exception {
-            logger.fine("connection to " + nodeAddr + " closed");
+        int availableCount = semaphore.drainPermits();
-            lock.lock();
+        if (availableCount == 0) {
-            try {
+            return availableCount;
-                synchronized (counts) {
+        }
-                    if(counts.containsKey(nodeAddr)) {
+        if (availableCount > maxCount) {
-                        counts.put(nodeAddr, counts.get(nodeAddr) - 1);
+            semaphore.release(availableCount - maxCount);
+            availableCount = maxCount;
+        }
+        Channel channel;
+        for (int i = 0; i < availableCount; i ++) {
+            if (null == (channel = poll())) {
+                channel = connectToAnyNode();
+            }
+            if (channel == null) {
+                semaphore.release(availableCount - i);
+                throw new ConnectException();
+            } else {
+                if (channelPoolhandler != null) {
+                    channelPoolhandler.channelAcquired(channel);
+                }
+                channels.add(channel);
             }
         }
-                synchronized (channels) {
+        return availableCount;
-                    List<Channel> nodeConns = channels.get(nodeAddr);
-                    if(nodeConns != null) {
-                        nodeConns.remove(conn);
     }
+
+    @Override
+    public void release(Channel channel) throws Exception {
+        K nodeAddr = channel.attr(attributeKey).get();
+        if (channel.isActive()) {
+            Queue<Channel> channelQueue = availableChannels.get(nodeAddr);
+            if (channelQueue != null) {
+                channelQueue.add(channel);
             }
             semaphore.release();
+        } else {
+            channel.close();
+        }
+        if (channelPoolhandler != null) {
+            channelPoolhandler.channelReleased(channel);
+        }
+    }
+
+    @Override
+    public void release(List<Channel> channels) throws Exception {
+        for (Channel channel : channels) {
+            release(channel);
+        }
+    }
+
+    @Override
+    public void close() {
+        lock.lock();
+        try {
+            int closedConnCount = 0;
+            for (K nodeAddr : availableChannels.keySet()) {
+                for (Channel conn : availableChannels.get(nodeAddr)) {
+                    if (conn.isOpen()) {
+                        conn.close();
+                        closedConnCount++;
+                    }
+                }
+            }
+            availableChannels.clear();
+            for (K nodeAddr : channels.keySet()) {
+                for (Channel channel : channels.get(nodeAddr)) {
+                    if (channel != null && channel.isOpen()) {
+                        channel.close();
+                        closedConnCount++;
+                    }
+                }
+            }
+            channels.clear();
+            bootstraps.clear();
+            counts.clear();
+            logger.log(Level.FINE, "closed " + closedConnCount + " connections");
         } finally {
             lock.unlock();
         }
     }
-    }
 
     private Channel connectToAnyNode() throws ConnectException {
         Channel channel = null;
-        String nodeAddr = null;
+        K nodeAddr = null;
-        String nextNodeAddr;
+        K nextNodeAddr;
         int min = Integer.MAX_VALUE;
         int next;
         int i = ThreadLocalRandom.current().nextInt(numberOfNodes);
@@ -170,28 +239,28 @@ public class SimpleChannelPool implements ChannelPool {
             }
         }
         if (nodeAddr != null) {
-            logger.fine("trying connection to " + nodeAddr);
+            logger.log(Level.FINE, "trying connection to " + nodeAddr);
             try {
                 channel = connect(nodeAddr);
             } catch (Exception e) {
-                logger.warning("failed to create a new connection to " + nodeAddr + ": " + e.toString());
+                logger.log(Level.WARNING, "failed to create a new connection to " + nodeAddr + ": " + e.toString());
                 if (retriesPerNode > 0) {
                     int selectedNodeFailedConnAttemptsCount = failedCounts.get(nodeAddr) + 1;
                     failedCounts.put(nodeAddr, selectedNodeFailedConnAttemptsCount);
                     if (selectedNodeFailedConnAttemptsCount > retriesPerNode) {
-                        logger.warning("Failed to connect to the node \"" + nodeAddr + "\" "
+                        logger.log(Level.WARNING, "failed to connect to the node " + nodeAddr + " "
-                                        + selectedNodeFailedConnAttemptsCount + " times successively, "
+                                        + selectedNodeFailedConnAttemptsCount + " times, "
-                                        + "excluding the node from the connection pool forever");
+                                        + "excluding the node from the connection pool");
                         counts.put(nodeAddr, Integer.MAX_VALUE);
                         boolean allNodesExcluded = true;
-                        for (String node : nodes) {
+                        for (K node : nodes) {
                             if (counts.get(node) < Integer.MAX_VALUE) {
                                 allNodesExcluded = false;
                                 break;
                             }
                         }
                         if (allNodesExcluded) {
-                            logger.severe("no endpoint nodes left in the connection pool");
+                            logger.log(Level.SEVERE, "no nodes left in the connection pool");
                         }
                     }
                 }
@@ -204,20 +273,20 @@ public class SimpleChannelPool implements ChannelPool {
         }
         if (channel != null) {
             channel.closeFuture().addListener(new CloseChannelListener(nodeAddr, channel));
-            channel.attr(NODE_ATTRIBUTE_KEY).set(nodeAddr);
+            channel.attr(attributeKey).set(nodeAddr);
-            channels.computeIfAbsent(nodeAddr, na -> new ArrayList<>()).add(channel);
+            channels.computeIfAbsent(nodeAddr, node -> new ArrayList<>()).add(channel);
-            synchronized(counts) {
+            synchronized (counts) {
                 counts.put(nodeAddr, counts.get(nodeAddr) + 1);
             }
             if(retriesPerNode > 0) {
                 failedCounts.put(nodeAddr, 0);
             }
-            logger.fine("new connection to " + nodeAddr + " created");
+            logger.log(Level.FINE,"new connection to " + nodeAddr + " created");
         }
         return channel;
     }
 
-    protected Channel connect(String addr) throws Exception {
+    private Channel connect(K addr) throws Exception {
         Bootstrap bootstrap = bootstraps.get(addr);
         if (bootstrap != null) {
             return bootstrap.connect().sync().channel();
@@ -231,9 +300,9 @@ public class SimpleChannelPool implements ChannelPool {
         Channel channel;
         for(int j = i; j < i + numberOfNodes; j ++) {
             channelQueue = availableChannels.get(nodes.get(j % numberOfNodes));
-            if(channelQueue != null) {
+            if (channelQueue != null) {
                 channel = channelQueue.poll();
-                if(channel != null && channel.isActive()) {
+                if (channel != null && channel.isActive()) {
                     return channel;
                 }
             }
@@ -241,100 +310,36 @@ public class SimpleChannelPool implements ChannelPool {
         return null;
     }
 
-    @Override
+    private class CloseChannelListener implements ChannelFutureListener {
-    public Channel lease() throws ConnectException {
+
-        Channel conn = null;
+        private final K nodeAddr;
-        if (semaphore.tryAcquire()) {
+        private final Channel channel;
-            if (null == (conn = poll())) {
+
-                conn = connectToAnyNode();
+        private CloseChannelListener(K nodeAddr, Channel channel) {
-            }
+            this.nodeAddr = nodeAddr;
-            if (conn == null) {
+            this.channel = channel;
-                semaphore.release();
-                throw new ConnectException();
-            }
-        }
-        return conn;
         }
 
         @Override
-    public int lease(List<Channel> channels, int maxCount) throws ConnectException {
+        public void operationComplete(ChannelFuture future) {
-        int availableCount = semaphore.drainPermits();
+            logger.log(Level.FINE,"connection to " + nodeAddr + " closed");
-        if (availableCount == 0) {
-            return availableCount;
-        }
-        if (availableCount > maxCount) {
-            semaphore.release(availableCount - maxCount);
-            availableCount = maxCount;
-        }
-        Channel conn;
-        for (int i = 0; i < availableCount; i ++) {
-            if (null == (conn = poll())) {
-                conn = connectToAnyNode();
-            }
-            if (conn == null) {
-                semaphore.release(availableCount - i);
-                throw new ConnectException();
-            } else {
-                channels.add(conn);
-            }
-        }
-        return availableCount;
-    }
-
-    @Override
-    public void release(Channel conn) {
-        String nodeAddr = conn.attr(NODE_ATTRIBUTE_KEY).get();
-        if( conn.isActive()) {
-            Queue<Channel> connQueue = availableChannels.get(nodeAddr);
-            if (connQueue != null) {
-                connQueue.add(conn);
-            }
-            semaphore.release();
-        } else {
-            conn.close();
-        }
-    }
-
-    @Override
-    public void release(List<Channel> conns) {
-        String nodeAddr;
-        Queue<Channel> connQueue;
-        for (Channel conn : conns) {
-            nodeAddr = conn.attr(NODE_ATTRIBUTE_KEY).get();
-            if (conn.isActive()) {
-                connQueue = availableChannels.get(nodeAddr);
-                connQueue.add(conn);
-                semaphore.release();
-            } else {
-                conn.close();
-            }
-        }
-    }
-
-    @Override
-    public void close() {
             lock.lock();
-        int closedConnCount = 0;
+            try {
-        for (String nodeAddr: availableChannels.keySet()) {
+                synchronized (counts) {
-            for (Channel conn: availableChannels.get(nodeAddr)) {
+                    if (counts.containsKey(nodeAddr)) {
-                if (conn.isOpen()) {
+                        counts.put(nodeAddr, counts.get(nodeAddr) - 1);
-                    conn.close();
-                    closedConnCount ++;
                     }
                 }
-        }
+                synchronized (channels) {
-        availableChannels.clear();
+                    List<Channel> channels = SimpleChannelPool.this.channels.get(nodeAddr);
-        for (String nodeAddr: channels.keySet()) {
+                    if (channels != null) {
-            for (Channel conn: channels.get(nodeAddr)) {
+                        channels.remove(channel);
-                if (conn.isOpen()) {
-                    conn.close();
-                    closedConnCount ++;
                     }
                 }
+                semaphore.release();
+            } finally {
+                lock.unlock();
+            }
         }
-        channels.clear();
-        bootstraps.clear();
-        counts.clear();
-        logger.fine("closed " + closedConnCount + " connections");
     }
 }

src/main/java/org/xbib/netty/http/client/rest/RestClient.java

@@ -11,7 +11,6 @@ import org.xbib.netty.http.client.RequestBuilder;
 import org.xbib.netty.http.client.transport.Transport;
 
 import java.io.IOException;
-import java.net.ConnectException;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.logging.Logger;
@@ -55,21 +54,14 @@ public class RestClient {
         Client client = new Client();
         Transport transport = client.newTransport(HttpAddress.http1(url));
         RestClient restClient = new RestClient(client, transport);
-        transport.setResponseListener(restClient::setResponse);
-        try {
-            transport.connect();
-        } catch (InterruptedException e) {
-            throw new ConnectException("unable to connect to " + url);
-        }
-        transport.awaitSettings();
         RequestBuilder requestBuilder = Request.builder(httpMethod);
-        requestBuilder.setURL(url);
+        requestBuilder.url(url);
         if (body != null && charset != null) {
             ByteBuf byteBuf = client.getByteBufAllocator().buffer();
             byteBuf.writeCharSequence(body, charset);
-            requestBuilder.setContent(byteBuf);
+            requestBuilder.content(byteBuf);
         }
-        transport.execute(requestBuilder.build()).get();
+        transport.execute(requestBuilder.build().setResponseListener(restClient::setResponse)).get();
         return restClient;
     }
 

src/main/java/org/xbib/netty/http/client/retry/BackOff.java

@@ -0,0 +1,65 @@
+package org.xbib.netty.http.client.retry;
+
+import java.io.IOException;
+
+/**
+ * Back-off policy when retrying an operation.
+ */
+public interface BackOff {
+
+    /**
+     * Indicates that no more retries should be made for use in {@link #nextBackOffMillis()}. */
+    long STOP = -1L;
+
+    /**
+     * Reset to initial state.
+     */
+    void reset() throws IOException;
+
+    /**
+     * Gets the number of milliseconds to wait before retrying the operation or {@link #STOP} to
+     * indicate that no retries should be made.
+     *
+     * <p>
+     * Example usage:
+     * </p>
+     *
+     * <pre>
+     long backOffMillis = backoff.nextBackOffMillis();
+     if (backOffMillis == Backoff.STOP) {
+     // do not retry operation
+     } else {
+     // sleep for backOffMillis milliseconds and retry operation
+     }
+     * </pre>
+     */
+    long nextBackOffMillis() throws IOException;
+
+    /**
+     * Fixed back-off policy whose back-off time is always zero, meaning that the operation is retried
+     * immediately without waiting.
+     */
+    BackOff ZERO_BACKOFF = new BackOff() {
+
+        public void reset() {
+        }
+
+        public long nextBackOffMillis() {
+            return 0;
+        }
+    };
+
+    /**
+     * Fixed back-off policy that always returns {@code #STOP} for {@link #nextBackOffMillis()},
+     * meaning that the operation should not be retried.
+     */
+    BackOff STOP_BACKOFF = new BackOff() {
+
+        public void reset() {
+        }
+
+        public long nextBackOffMillis() {
+            return STOP;
+        }
+    };
+}

src/main/java/org/xbib/netty/http/client/retry/ExponentialBackOff.java

@@ -0,0 +1,487 @@
+package org.xbib.netty.http.client.retry;
+
+/**
+ * Implementation of {@link BackOff} that increases the back off period for each retry attempt using
+ * a randomization function that grows exponentially.
+ *
+ * <p>
+ * {@link #nextBackOffMillis()} is calculated using the following formula:
+ * </p>
+ *
+ * <pre>
+ randomized_interval =
+ retry_interval * (random value in range [1 - randomization_factor, 1 + randomization_factor])
+ * </pre>
+ *
+ * <p>
+ * In other words {@link #nextBackOffMillis()} will range between the randomization factor
+ * percentage below and above the retry interval. For example, using 2 seconds as the base retry
+ * interval and 0.5 as the randomization factor, the actual back off period used in the next retry
+ * attempt will be between 1 and 3 seconds.
+ * </p>
+ *
+ * <p>
+ * <b>Note:</b> max_interval caps the retry_interval and not the randomized_interval.
+ * </p>
+ *
+ * <p>
+ * If the time elapsed since an {@link ExponentialBackOff} instance is created goes past the
+ * max_elapsed_time then the method {@link #nextBackOffMillis()} starts returning
+ * {@link BackOff#STOP}. The elapsed time can be reset by calling {@link #reset()}.
+ * </p>
+ *
+ * <p>
+ * Example: The default retry_interval is .5 seconds, default randomization_factor is 0.5, default
+ * multiplier is 1.5 and the default max_interval is 1 minute. For 10 tries the sequence will be
+ * (values in seconds) and assuming we go over the max_elapsed_time on the 10th try:
+ * </p>
+ *
+ * <pre>
+ request#     retry_interval     randomized_interval
+
+ 1             0.5                [0.25,   0.75]
+ 2             0.75               [0.375,  1.125]
+ 3             1.125              [0.562,  1.687]
+ 4             1.687              [0.8435, 2.53]
+ 5             2.53               [1.265,  3.795]
+ 6             3.795              [1.897,  5.692]
+ 7             5.692              [2.846,  8.538]
+ 8             8.538              [4.269, 12.807]
+ 9            12.807              [6.403, 19.210]
+ 10           19.210              {@link BackOff#STOP}
+ * </pre>
+ *
+ * <p>
+ * Implementation is not thread-safe.
+ * </p>
+ */
+public class ExponentialBackOff implements BackOff {
+
+    /** The default initial interval value in milliseconds (0.5 seconds). */
+    public static final int DEFAULT_INITIAL_INTERVAL_MILLIS = 500;
+
+    /**
+     * The default randomization factor (0.5 which results in a random period ranging between 50%
+     * below and 50% above the retry interval).
+     */
+    public static final double DEFAULT_RANDOMIZATION_FACTOR = 0.5;
+
+    /** The default multiplier value (1.5 which is 50% increase per back off). */
+    public static final double DEFAULT_MULTIPLIER = 1.5;
+
+    /** The default maximum back off time in milliseconds (1 minute). */
+    public static final int DEFAULT_MAX_INTERVAL_MILLIS = 60000;
+
+    /** The default maximum elapsed time in milliseconds (15 minutes). */
+    public static final int DEFAULT_MAX_ELAPSED_TIME_MILLIS = 900000;
+
+    /** The current retry interval in milliseconds. */
+    private int currentIntervalMillis;
+
+    /** The initial retry interval in milliseconds. */
+    private final int initialIntervalMillis;
+
+    /**
+     * The randomization factor to use for creating a range around the retry interval.
+     *
+     * <p>
+     * A randomization factor of 0.5 results in a random period ranging between 50% below and 50%
+     * above the retry interval.
+     * </p>
+     */
+    private final double randomizationFactor;
+
+    /** The value to multiply the current interval with for each retry attempt. */
+    private final double multiplier;
+
+    /**
+     * The maximum value of the back off period in milliseconds. Once the retry interval reaches this
+     * value it stops increasing.
+     */
+    private final int maxIntervalMillis;
+
+    /**
+     * The system time in nanoseconds. It is calculated when an ExponentialBackOffPolicy instance is
+     * created and is reset when {@link #reset()} is called.
+     */
+    private long startTimeNanos;
+
+    /**
+     * The maximum elapsed time after instantiating {@link ExponentialBackOff} or calling
+     * {@link #reset()} after which {@link #nextBackOffMillis()} returns {@link BackOff#STOP}.
+     */
+    private final int maxElapsedTimeMillis;
+
+    /** Nano clock. */
+    private final NanoClock nanoClock;
+
+    /**
+     * Creates an instance of ExponentialBackOffPolicy using default values.
+     *
+     * <p>
+     * To override the defaults use {@link Builder}.
+     * </p>
+     *
+     * <ul>
+     * <li>{@code initialIntervalMillis} defaults to {@link #DEFAULT_INITIAL_INTERVAL_MILLIS}</li>
+     * <li>{@code randomizationFactor} defaults to {@link #DEFAULT_RANDOMIZATION_FACTOR}</li>
+     * <li>{@code multiplier} defaults to {@link #DEFAULT_MULTIPLIER}</li>
+     * <li>{@code maxIntervalMillis} defaults to {@link #DEFAULT_MAX_INTERVAL_MILLIS}</li>
+     * <li>{@code maxElapsedTimeMillis} defaults in {@link #DEFAULT_MAX_ELAPSED_TIME_MILLIS}</li>
+     * </ul>
+     */
+    public ExponentialBackOff() {
+        this(new Builder());
+    }
+
+    /**
+     * @param builder builder
+     */
+    protected ExponentialBackOff(Builder builder) {
+        initialIntervalMillis = builder.initialIntervalMillis;
+        randomizationFactor = builder.randomizationFactor;
+        multiplier = builder.multiplier;
+        maxIntervalMillis = builder.maxIntervalMillis;
+        maxElapsedTimeMillis = builder.maxElapsedTimeMillis;
+        nanoClock = builder.nanoClock;
+        //Preconditions.checkArgument(initialIntervalMillis > 0);
+        //Preconditions.checkArgument(0 <= randomizationFactor && randomizationFactor < 1);
+        //Preconditions.checkArgument(multiplier >= 1);
+        //Preconditions.checkArgument(maxIntervalMillis >= initialIntervalMillis);
+        //Preconditions.checkArgument(maxElapsedTimeMillis > 0);
+        reset();
+    }
+
+    /** Sets the interval back to the initial retry interval and restarts the timer. */
+    public final void reset() {
+        currentIntervalMillis = initialIntervalMillis;
+        startTimeNanos = nanoClock.nanoTime();
+    }
+
+    public void setStartTimeNanos(long startTimeNanos) {
+        this.startTimeNanos = startTimeNanos;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>
+     * This method calculates the next back off interval using the formula: randomized_interval =
+     * retry_interval +/- (randomization_factor * retry_interval)
+     * </p>
+     *
+     * <p>
+     * Subclasses may override if a different algorithm is required.
+     * </p>
+     */
+    public long nextBackOffMillis() {
+        // Make sure we have not gone over the maximum elapsed time.
+        if (getElapsedTimeMillis() > maxElapsedTimeMillis) {
+            return STOP;
+        }
+        int randomizedInterval =
+                getRandomValueFromInterval(randomizationFactor, Math.random(), currentIntervalMillis);
+        incrementCurrentInterval();
+        return randomizedInterval;
+    }
+
+    /**
+     * Returns a random value from the interval [randomizationFactor * currentInterval,
+     * randomizationFactor * currentInterval].
+     */
+    public static int getRandomValueFromInterval(double randomizationFactor, double random, int currentIntervalMillis) {
+        double delta = randomizationFactor * currentIntervalMillis;
+        double minInterval = currentIntervalMillis - delta;
+        double maxInterval = currentIntervalMillis + delta;
+        // Get a random value from the range [minInterval, maxInterval].
+        // The formula used below has a +1 because if the minInterval is 1 and the maxInterval is 3 then
+        // we want a 33% chance for selecting either 1, 2 or 3.
+        return (int) (minInterval + (random * (maxInterval - minInterval + 1)));
+    }
+
+    /** Returns the initial retry interval in milliseconds. */
+    public final int getInitialIntervalMillis() {
+        return initialIntervalMillis;
+    }
+
+    /**
+     * Returns the randomization factor to use for creating a range around the retry interval.
+     *
+     * <p>
+     * A randomization factor of 0.5 results in a random period ranging between 50% below and 50%
+     * above the retry interval.
+     * </p>
+     */
+    public final double getRandomizationFactor() {
+        return randomizationFactor;
+    }
+
+    /**
+     * Returns the current retry interval in milliseconds.
+     */
+    public final int getCurrentIntervalMillis() {
+        return currentIntervalMillis;
+    }
+
+    /**
+     * Returns the value to multiply the current interval with for each retry attempt.
+     */
+    public final double getMultiplier() {
+        return multiplier;
+    }
+
+    /**
+     * Returns the maximum value of the back off period in milliseconds. Once the current interval
+     * reaches this value it stops increasing.
+     */
+    public final int getMaxIntervalMillis() {
+        return maxIntervalMillis;
+    }
+
+    /**
+     * Returns the maximum elapsed time in milliseconds.
+     *
+     * <p>
+     * If the time elapsed since an {@link ExponentialBackOff} instance is created goes past the
+     * max_elapsed_time then the method {@link #nextBackOffMillis()} starts returning
+     * {@link BackOff#STOP}. The elapsed time can be reset by calling {@link #reset()}.
+     * </p>
+     */
+    public final int getMaxElapsedTimeMillis() {
+        return maxElapsedTimeMillis;
+    }
+
+    /**
+     * Returns the elapsed time in milliseconds since an {@link ExponentialBackOff} instance is
+     * created and is reset when {@link #reset()} is called.
+     *
+     * <p>
+     * The elapsed time is computed using {@link System#nanoTime()}.
+     * </p>
+     */
+    public final long getElapsedTimeMillis() {
+        return (nanoClock.nanoTime() - startTimeNanos) / 1000000;
+    }
+
+    /**
+     * Increments the current interval by multiplying it with the multiplier.
+     */
+    private void incrementCurrentInterval() {
+        // Check for overflow, if overflow is detected set the current interval to the max interval.
+        if (currentIntervalMillis >= maxIntervalMillis / multiplier) {
+            currentIntervalMillis = maxIntervalMillis;
+        } else {
+            currentIntervalMillis *= multiplier;
+        }
+    }
+
+    /**
+     * Builder for {@link ExponentialBackOff}.
+     *
+     * <p>
+     * Implementation is not thread-safe.
+     * </p>
+     */
+    public static class Builder {
+
+        /** The initial retry interval in milliseconds. */
+        int initialIntervalMillis = DEFAULT_INITIAL_INTERVAL_MILLIS;
+
+        /**
+         * The randomization factor to use for creating a range around the retry interval.
+         *
+         * <p>
+         * A randomization factor of 0.5 results in a random period ranging between 50% below and 50%
+         * above the retry interval.
+         * </p>
+         */
+        double randomizationFactor = DEFAULT_RANDOMIZATION_FACTOR;
+
+        /** The value to multiply the current interval with for each retry attempt. */
+        double multiplier = DEFAULT_MULTIPLIER;
+
+        /**
+         * The maximum value of the back off period in milliseconds. Once the retry interval reaches
+         * this value it stops increasing.
+         */
+        int maxIntervalMillis = DEFAULT_MAX_INTERVAL_MILLIS;
+
+        /**
+         * The maximum elapsed time in milliseconds after instantiating {@link ExponentialBackOff} or
+         * calling {@link #reset()} after which {@link #nextBackOffMillis()} returns
+         * {@link BackOff#STOP}.
+         */
+        int maxElapsedTimeMillis = DEFAULT_MAX_ELAPSED_TIME_MILLIS;
+
+        /** Nano clock. */
+        NanoClock nanoClock = NanoClock.SYSTEM;
+
+        public Builder() {
+        }
+
+        /** Builds a new instance of {@link ExponentialBackOff}. */
+        public ExponentialBackOff build() {
+            return new ExponentialBackOff(this);
+        }
+
+        /**
+         * Returns the initial retry interval in milliseconds. The default value is
+         * {@link #DEFAULT_INITIAL_INTERVAL_MILLIS}.
+         */
+        public final int getInitialIntervalMillis() {
+            return initialIntervalMillis;
+        }
+
+        /**
+         * Sets the initial retry interval in milliseconds. The default value is
+         * {@link #DEFAULT_INITIAL_INTERVAL_MILLIS}. Must be {@code > 0}.
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setInitialIntervalMillis(int initialIntervalMillis) {
+            this.initialIntervalMillis = initialIntervalMillis;
+            return this;
+        }
+
+        /**
+         * Returns the randomization factor to use for creating a range around the retry interval. The
+         * default value is {@link #DEFAULT_RANDOMIZATION_FACTOR}.
+         *
+         * <p>
+         * A randomization factor of 0.5 results in a random period ranging between 50% below and 50%
+         * above the retry interval.
+         * </p>
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public final double getRandomizationFactor() {
+            return randomizationFactor;
+        }
+
+        /**
+         * Sets the randomization factor to use for creating a range around the retry interval. The
+         * default value is {@link #DEFAULT_RANDOMIZATION_FACTOR}. Must fall in the range
+         * {@code 0 <= randomizationFactor < 1}.
+         *
+         * <p>
+         * A randomization factor of 0.5 results in a random period ranging between 50% below and 50%
+         * above the retry interval.
+         * </p>
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setRandomizationFactor(double randomizationFactor) {
+            this.randomizationFactor = randomizationFactor;
+            return this;
+        }
+
+        /**
+         * Returns the value to multiply the current interval with for each retry attempt. The default
+         * value is {@link #DEFAULT_MULTIPLIER}.
+         */
+        public final double getMultiplier() {
+            return multiplier;
+        }
+
+        /**
+         * Sets the value to multiply the current interval with for each retry attempt. The default
+         * value is {@link #DEFAULT_MULTIPLIER}. Must be {@code >= 1}.
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setMultiplier(double multiplier) {
+            this.multiplier = multiplier;
+            return this;
+        }
+
+        /**
+         * Returns the maximum value of the back off period in milliseconds. Once the current interval
+         * reaches this value it stops increasing. The default value is
+         * {@link #DEFAULT_MAX_INTERVAL_MILLIS}. Must be {@code >= initialInterval}.
+         */
+        public final int getMaxIntervalMillis() {
+            return maxIntervalMillis;
+        }
+
+        /**
+         * Sets the maximum value of the back off period in milliseconds. Once the current interval
+         * reaches this value it stops increasing. The default value is
+         * {@link #DEFAULT_MAX_INTERVAL_MILLIS}.
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setMaxIntervalMillis(int maxIntervalMillis) {
+            this.maxIntervalMillis = maxIntervalMillis;
+            return this;
+        }
+
+        /**
+         * Returns the maximum elapsed time in milliseconds. The default value is
+         * {@link #DEFAULT_MAX_ELAPSED_TIME_MILLIS}.
+         *
+         * <p>
+         * If the time elapsed since an {@link ExponentialBackOff} instance is created goes past the
+         * max_elapsed_time then the method {@link #nextBackOffMillis()} starts returning
+         * {@link BackOff#STOP}. The elapsed time can be reset by calling {@link #reset()}.
+         * </p>
+         */
+        public final int getMaxElapsedTimeMillis() {
+            return maxElapsedTimeMillis;
+        }
+
+        /**
+         * Sets the maximum elapsed time in milliseconds. The default value is
+         * {@link #DEFAULT_MAX_ELAPSED_TIME_MILLIS}. Must be {@code > 0}.
+         *
+         * <p>
+         * If the time elapsed since an {@link ExponentialBackOff} instance is created goes past the
+         * max_elapsed_time then the method {@link #nextBackOffMillis()} starts returning
+         * {@link BackOff#STOP}. The elapsed time can be reset by calling {@link #reset()}.
+         * </p>
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setMaxElapsedTimeMillis(int maxElapsedTimeMillis) {
+            this.maxElapsedTimeMillis = maxElapsedTimeMillis;
+            return this;
+        }
+
+        /**
+         * Returns the nano clock.
+         */
+        public final NanoClock getNanoClock() {
+            return nanoClock;
+        }
+
+        /**
+         * Sets the nano clock ({@link NanoClock#SYSTEM} by default).
+         *
+         * <p>
+         * Overriding is only supported for the purpose of calling the super implementation and changing
+         * the return type, but nothing else.
+         * </p>
+         */
+        public Builder setNanoClock(NanoClock nanoClock) {
+            this.nanoClock = nanoClock; //Preconditions.checkNotNull(nanoClock);
+            return this;
+        }
+    }
+}

src/main/java/org/xbib/netty/http/client/retry/NanoClock.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2013 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package org.xbib.netty.http.client.retry;
+
+/**
+ * Nano clock which can be used to measure elapsed time in nanoseconds.
+ *
+ * <p>
+ * The default system implementation can be accessed at {@link #SYSTEM}. Alternative implementations
+ * may be used for testing.
+ * </p>
+ *
+ * @since 1.14
+ * @author Yaniv Inbar
+ */
+public interface NanoClock {
+
+  /**
+   * Returns the current value of the most precise available system timer, in nanoseconds for use to
+   * measure elapsed time, to match the behavior of {@link System#nanoTime()}.
+   */
+  long nanoTime();
+
+  /**
+   * Provides the default System implementation of a nano clock by using {@link System#nanoTime()}.
+   */
+  NanoClock SYSTEM = new NanoClock() {
+    public long nanoTime() {
+      return System.nanoTime();
+    }
+  };
+}

src/main/java/org/xbib/netty/http/client/transport/BaseTransport.java

@@ -16,12 +16,9 @@ import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.HttpAddress;
 import org.xbib.netty.http.client.Request;
 import org.xbib.netty.http.client.RequestBuilder;
-import org.xbib.netty.http.client.listener.CookieListener;
-import org.xbib.netty.http.client.listener.ExceptionListener;
-import org.xbib.netty.http.client.listener.HttpHeadersListener;
-import org.xbib.netty.http.client.listener.HttpPushListener;
-import org.xbib.netty.http.client.listener.HttpResponseListener;
 
+import java.io.IOException;
+import java.net.ConnectException;
 import java.nio.charset.MalformedInputException;
 import java.nio.charset.StandardCharsets;
 import java.nio.charset.UnmappableCharacterException;
@@ -51,16 +48,6 @@ abstract class BaseTransport implements Transport {
 
     protected SortedMap<Integer, Request> requests;
 
-    protected HttpResponseListener responseListener;
-
-    protected ExceptionListener exceptionListener;
-
-    protected HttpHeadersListener httpHeadersListener;
-
-    protected CookieListener cookieListener;
-
-    protected HttpPushListener pushListener;
-
     private Map<Cookie, Boolean> cookieBox;
 
     BaseTransport(Client client, HttpAddress httpAddress) {
@@ -75,31 +62,8 @@ abstract class BaseTransport implements Transport {
     }
 
     @Override
-    public void connect() throws InterruptedException {
+    public Transport execute(Request request) throws IOException {
-        channel = client.newChannel(httpAddress);
+        ensureConnect();
-        channel.attr(TRANSPORT_ATTRIBUTE_KEY).set(this);
-    }
-
-    @Override
-    public Channel channel() {
-        return channel;
-    }
-
-    @Override
-    public Transport execute(Request request) {
-        if (channel == null) {
-            try {
-                connect();
-                awaitSettings();
-            } catch (InterruptedException e) {
-                return this;
-            }
-        }
-        setResponseListener(request.getResponseListener());
-        setExceptionListener(request.getExceptionListener());
-        setHeadersListener(request.getHeadersListener());
-        setCookieListener(request.getCookieListener());
-        setPushListener(request.getPushListener());
         // some HTTP 1.1 servers like Elasticsearch do not understand full URIs in HTTP command line
         String uri = request.httpVersion().majorVersion() < 2 ?
                 request.base().relativeReference() : request.base().toString();
@@ -136,91 +100,45 @@ abstract class BaseTransport implements Transport {
      */
     @Override
     public <T> CompletableFuture<T> execute(Request request,
-                                            Function<FullHttpResponse, T> supplier) {
+                                            Function<FullHttpResponse, T> supplier) throws IOException {
         final CompletableFuture<T> completableFuture = new CompletableFuture<>();
-        request.setExceptionListener(completableFuture::completeExceptionally);
+        //request.setExceptionListener(completableFuture::completeExceptionally);
         request.setResponseListener(response -> completableFuture.complete(supplier.apply(response)));
         execute(request);
         return completableFuture;
     }
 
     @Override
-    public void close() {
+    public synchronized void close() {
         get();
         if (channel != null) {
             channel.close();
+            channel = null;
         }
     }
 
-    @Override
+    protected void ensureConnect() throws IOException {
-    public void setResponseListener(HttpResponseListener responseListener) {
+        if (channel == null) {
-        if (responseListener != null) {
+            try {
-            this.responseListener = responseListener;
+                channel = client.newChannel(httpAddress);
+                channel.attr(TRANSPORT_ATTRIBUTE_KEY).set(this);
+                awaitSettings();
+            } catch (InterruptedException e) {
+                throw new ConnectException("unable to connect to " + httpAddress);
             }
         }
-
-    @Override
-    public HttpResponseListener getResponseListener() {
-        return responseListener;
-    }
-
-    @Override
-    public void setHeadersListener(HttpHeadersListener httpHeadersListener) {
-        if (httpHeadersListener != null) {
-            this.httpHeadersListener = httpHeadersListener;
-        }
-    }
-
-    @Override
-    public HttpHeadersListener getHeadersListener() {
-        return httpHeadersListener;
-    }
-
-    @Override
-    public void setCookieListener(CookieListener cookieListener) {
-        if (cookieListener != null) {
-            this.cookieListener = cookieListener;
-        }
-    }
-
-    @Override
-    public CookieListener getCookieListener() {
-        return cookieListener;
-    }
-
-    @Override
-    public void setExceptionListener(ExceptionListener exceptionListener) {
-        if (exceptionListener != null) {
-            this.exceptionListener = exceptionListener;
-        }
-    }
-
-    @Override
-    public ExceptionListener getExceptionListener() {
-        return exceptionListener;
-    }
-
-    @Override
-    public void setPushListener(HttpPushListener pushListener) {
-        if (pushListener != null) {
-            this.pushListener = pushListener;
-        }
-    }
-
-    @Override
-    public HttpPushListener getPushListener() {
-        return pushListener;
     }
 
     protected Request continuation(Integer streamId, FullHttpResponse httpResponse) throws URLSyntaxException {
         if (httpResponse == null) {
             return null;
         }
-        try {
+        Request request = fromStreamId(streamId);
-            if (streamId == null) {
+        if (request == null) {
-                streamId = requests.lastKey();
+            // push promise
+            return null;
         }
-            Request request = requests.get(streamId);
+        try {
             if (request.checkRedirect()) {
                 int status = httpResponse.status().code();
                 switch (status) {
@@ -238,20 +156,21 @@ abstract class BaseTransport implements Transport {
                             URL redirUrl = URL.base(request.base()).resolve(location);
                             HttpMethod method = httpResponse.status().code() == 303 ? HttpMethod.GET : request.httpMethod();
                             RequestBuilder newHttpRequestBuilder = Request.builder(method)
-                                    .setURL(redirUrl)
+                                    .url(redirUrl)
                                     .setVersion(request.httpVersion())
                                     .setHeaders(request.headers())
-                                    .setContent(request.content());
+                                    .content(request.content());
+                            // TODO(jprante) convencience to copy pathAndQuery from one request to another
                             request.base().getQueryParams().forEach(pair ->
-                                newHttpRequestBuilder.addParam(pair.getFirst(), pair.getSecond())
+                                newHttpRequestBuilder.addParameter(pair.getFirst(), pair.getSecond())
                             );
                             request.cookies().forEach(newHttpRequestBuilder::addCookie);
                             Request newHttpRequest = newHttpRequestBuilder.build();
                             newHttpRequest.setResponseListener(request.getResponseListener());
-                            newHttpRequest.setExceptionListener(request.getExceptionListener());
+                            //newHttpRequest.setExceptionListener(request.getExceptionListener());
                             newHttpRequest.setHeadersListener(request.getHeadersListener());
                             newHttpRequest.setCookieListener(request.getCookieListener());
-                            newHttpRequest.setPushListener(request.getPushListener());
+                            //newHttpRequest.setPushListener(request.getPushListener());
                             StringBuilder hostAndPort = new StringBuilder();
                             hostAndPort.append(redirUrl.getHost());
                             if (redirUrl.getPort() != null) {
@@ -275,6 +194,13 @@ abstract class BaseTransport implements Transport {
         return null;
     }
 
+    protected Request fromStreamId(Integer streamId) {
+        if (streamId == null) {
+            streamId = requests.lastKey();
+        }
+       return requests.get(streamId);
+    }
+
     public void setCookieBox(Map<Cookie, Boolean> cookieBox) {
         this.cookieBox = cookieBox;
     }

src/main/java/org/xbib/netty/http/client/transport/Http2Transport.java

@@ -6,12 +6,17 @@ import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.cookie.ClientCookieDecoder;
 import io.netty.handler.codec.http.cookie.Cookie;
+import io.netty.handler.codec.http2.Http2Headers;
 import io.netty.handler.codec.http2.Http2Settings;
 import org.xbib.net.URLSyntaxException;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.HttpAddress;
 import org.xbib.netty.http.client.Request;
+import org.xbib.netty.http.client.listener.CookieListener;
+import org.xbib.netty.http.client.listener.HttpHeadersListener;
+import org.xbib.netty.http.client.listener.HttpResponseListener;
 
+import java.io.IOException;
 import java.util.SortedMap;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentSkipListMap;
@@ -36,11 +41,6 @@ public class Http2Transport extends BaseTransport implements Transport {
         super(client, httpAddress);
         streamIdCounter = new AtomicInteger(3);
         streamidPromiseMap = new ConcurrentSkipListMap<>();
-    }
-
-    @Override
-    public void connect() throws InterruptedException {
-        super.connect();
         settingsPromise = new CompletableFuture<>();
     }
 
@@ -86,34 +86,38 @@ public class Http2Transport extends BaseTransport implements Transport {
         }
         CompletableFuture<Boolean> promise = streamidPromiseMap.get(streamId);
         if (promise == null) {
-            logger.log(Level.WARNING, "message received for unknown stream id " + streamId);
+            logger.log(Level.WARNING, "response received for unknown stream id " + streamId);
-            if (pushListener != null) {
-                pushListener.onPushReceived(null, fullHttpResponse);
-            }
         } else {
+            Request request = fromStreamId(streamId);
+            if (request != null) {
+                HttpResponseListener responseListener = request.getResponseListener();
                 if (responseListener != null) {
                     responseListener.onResponse(fullHttpResponse);
                 }
-            // forward?
                 try {
-                Request request = continuation(streamId, fullHttpResponse);
+                    request = continuation(streamId, fullHttpResponse);
                     if (request != null) {
                         // synchronous call here
                         client.continuation(this, request);
                     }
-            } catch (URLSyntaxException e) {
+                } catch (URLSyntaxException | IOException e) {
                     logger.log(Level.WARNING, e.getMessage(), e);
                 }
-            // complete origin transport
+            }
+            // complete origin
             promise.complete(true);
         }
     }
 
     @Override
     public void headersReceived(Integer streamId, HttpHeaders httpHeaders) {
+        Request request = fromStreamId(streamId);
+        if (request != null) {
+            HttpHeadersListener httpHeadersListener = request.getHeadersListener();
             if (httpHeadersListener != null) {
                 httpHeadersListener.onHeaders(httpHeaders);
             }
+            CookieListener cookieListener = request.getCookieListener();
             if (cookieListener != null) {
                 for (String cookieString : httpHeaders.getAll(HttpHeaderNames.SET_COOKIE)) {
                     Cookie cookie = ClientCookieDecoder.STRICT.decode(cookieString);
@@ -121,6 +125,13 @@ public class Http2Transport extends BaseTransport implements Transport {
                 }
             }
         }
+    }
+
+    @Override
+    public void pushPromiseReceived(Integer streamId, Integer promisedStreamId, Http2Headers headers) {
+        streamidPromiseMap.put(promisedStreamId, new CompletableFuture<>());
+        requests.put(promisedStreamId, fromStreamId(streamId));
+    }
 
     @Override
     public void awaitResponse(Integer streamId) {
@@ -156,9 +167,6 @@ public class Http2Transport extends BaseTransport implements Transport {
 
     @Override
     public void fail(Throwable throwable) {
-        if (exceptionListener != null) {
-            exceptionListener.onException(throwable);
-        }
         for (CompletableFuture<Boolean> promise : streamidPromiseMap.values()) {
             promise.completeExceptionally(throwable);
         }

src/main/java/org/xbib/netty/http/client/transport/HttpTransport.java

@@ -6,12 +6,17 @@ import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.cookie.ClientCookieDecoder;
 import io.netty.handler.codec.http.cookie.Cookie;
+import io.netty.handler.codec.http2.Http2Headers;
 import io.netty.handler.codec.http2.Http2Settings;
 import org.xbib.net.URLSyntaxException;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.HttpAddress;
 import org.xbib.netty.http.client.Request;
+import org.xbib.netty.http.client.listener.CookieListener;
+import org.xbib.netty.http.client.listener.HttpHeadersListener;
+import org.xbib.netty.http.client.listener.HttpResponseListener;
 
+import java.io.IOException;
 import java.util.SortedMap;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentSkipListMap;
@@ -58,15 +63,19 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public void responseReceived(Integer streamId, FullHttpResponse fullHttpResponse) {
+        Request request = fromStreamId(streamId);
+        if (request != null) {
+            HttpResponseListener responseListener = request.getResponseListener();
             if (responseListener != null) {
                 responseListener.onResponse(fullHttpResponse);
             }
+        }
         try {
-            Request request = continuation(null, fullHttpResponse);
+            request = continuation(null, fullHttpResponse);
             if (request != null) {
                 client.continuation(this, request);
             }
-        } catch (URLSyntaxException e) {
+        } catch (URLSyntaxException | IOException e) {
             logger.log(Level.WARNING, e.getMessage(), e);
         }
         if (!sequentialPromiseMap.isEmpty()) {
@@ -79,17 +88,26 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public void headersReceived(Integer streamId, HttpHeaders httpHeaders) {
+        Request request =  fromStreamId(streamId);
+        if (request != null) {
+            HttpHeadersListener httpHeadersListener = request.getHeadersListener();
             if (httpHeadersListener != null) {
                 httpHeadersListener.onHeaders(httpHeaders);
             }
             for (String cookieString : httpHeaders.getAll(HttpHeaderNames.SET_COOKIE)) {
                 Cookie cookie = ClientCookieDecoder.STRICT.decode(cookieString);
                 addCookie(cookie);
+                CookieListener cookieListener = request.getCookieListener();
                 if (cookieListener != null) {
                     cookieListener.onCookie(cookie);
                 }
             }
         }
+    }
+
+    @Override
+    public void pushPromiseReceived(Integer streamId, Integer promisedStreamId, Http2Headers headers) {
+    }
 
     @Override
     public void awaitResponse(Integer streamId) {
@@ -125,11 +143,9 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public void fail(Throwable throwable) {
-        if (exceptionListener != null) {
-            exceptionListener.onException(throwable);
-        }
         for (CompletableFuture<Boolean> promise : sequentialPromiseMap.values()) {
             promise.completeExceptionally(throwable);
         }
     }
+
 }

src/main/java/org/xbib/netty/http/client/transport/Transport.java

@@ -4,16 +4,13 @@ import io.netty.channel.Channel;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.cookie.Cookie;
+import io.netty.handler.codec.http2.Http2Headers;
 import io.netty.handler.codec.http2.Http2Settings;
 import io.netty.util.AttributeKey;
 import org.xbib.netty.http.client.HttpAddress;
 import org.xbib.netty.http.client.Request;
-import org.xbib.netty.http.client.listener.CookieListener;
-import org.xbib.netty.http.client.listener.ExceptionListener;
-import org.xbib.netty.http.client.listener.HttpHeadersListener;
-import org.xbib.netty.http.client.listener.HttpPushListener;
-import org.xbib.netty.http.client.listener.HttpResponseListener;
 
+import java.io.IOException;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Function;
@@ -24,13 +21,9 @@ public interface Transport {
 
     HttpAddress httpAddress();
 
-    void connect() throws InterruptedException;
+    Transport execute(Request request) throws IOException;
 
-    Transport execute(Request request);
+    <T> CompletableFuture<T> execute(Request request, Function<FullHttpResponse, T> supplier) throws IOException;
-
-    <T> CompletableFuture<T> execute(Request request, Function<FullHttpResponse, T> supplier);
-
-    Channel channel();
 
     Integer nextStream();
 
@@ -38,26 +31,6 @@ public interface Transport {
 
     void awaitSettings();
 
-    void setResponseListener(HttpResponseListener responseListener);
-
-    HttpResponseListener getResponseListener();
-
-    void setExceptionListener(ExceptionListener exceptionListener);
-
-    ExceptionListener getExceptionListener();
-
-    void setHeadersListener(HttpHeadersListener headersListener);
-
-    HttpHeadersListener getHeadersListener();
-
-    void setPushListener(HttpPushListener pushListener);
-
-    HttpPushListener getPushListener();
-
-    void setCookieListener(CookieListener cookieListener);
-
-    CookieListener getCookieListener();
-
     void setCookieBox(Map<Cookie, Boolean> cookieBox);
 
     Map<Cookie, Boolean> getCookieBox();
@@ -66,6 +39,8 @@ public interface Transport {
 
     void headersReceived(Integer streamId, HttpHeaders httpHeaders);
 
+    void pushPromiseReceived(Integer streamId, Integer promisedStreamId, Http2Headers headers);
+
     void awaitResponse(Integer streamId);
 
     Transport get();

src/test/java/org/xbib/netty/http/client/test/AkamaiTest.java

@@ -1,57 +0,0 @@
-package org.xbib.netty.http.client.test;
-
-import org.junit.Ignore;
-import org.junit.Test;
-import org.xbib.netty.http.client.Client;
-import org.xbib.netty.http.client.Request;
-import org.xbib.netty.http.client.test.LoggingBase;
-
-import java.nio.charset.StandardCharsets;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-@Ignore
-public class AkamaiTest extends LoggingBase {
-
-    private static final Logger logger = Logger.getLogger("");
-
-    /**
-     * h2_demo_frame.html fails with:
-     * 2018-02-27 23:43:32.048 INFORMATION [client] io.netty.handler.codec.http2.Http2FrameLogger
-     * logRstStream [id: 0x4fe29f1e, L:/192.168.178.23:49429 - R:http2.akamai.com/104.94.191.203:443]
-     * INBOUND RST_STREAM: streamId=2 errorCode=8
-     * 2018-02-27 23:43:32.049 SCHWERWIEGEND [] org.xbib.netty.http.client.test.a.AkamaiTest lambda$testAkamaiHttps$0
-     * HTTP/2 to HTTP layer caught stream reset
-     * io.netty.handler.codec.http2.Http2Exception$StreamException: HTTP/2 to HTTP layer caught stream reset
-     *
-     * TODO(jprante) catch all promised pushes
-     */
-    @Test
-    public void testAkamaiHttps() {
-        Client client = new Client();
-        try {
-            Request request = Request.get()
-                    //.setURL("https://http2.akamai.com/demo/h2_demo_frame.html")
-                    .setURL("https://http2.akamai.com/")
-                    .setVersion("HTTP/2.0")
-                    .build()
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e))
-                    .setResponseListener(fullHttpResponse -> {
-                        String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
-                        logger.log(Level.INFO, "status = " + fullHttpResponse.status()
-                                + " response body = " + response);
-                    })
-                    .setPushListener((requestHeaders, fullHttpResponse) -> {
-                        String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
-                        logger.log(Level.INFO, "received push: request headers = " + requestHeaders
-                                + " status = " + fullHttpResponse.status()
-                                + " response headers = " + fullHttpResponse.headers().entries()
-                                + " response body = " + response
-                        );
-                    });
-            client.execute(request).get();
-        } finally {
-            client.shutdownGracefully();
-        }
-    }
-}

src/test/java/org/xbib/netty/http/client/test/ClientTest.java

@@ -1,181 +0,0 @@
-package org.xbib.netty.http.client.test;
-
-import io.netty.handler.codec.http.HttpMethod;
-import org.junit.Test;
-import org.xbib.netty.http.client.Client;
-import org.xbib.netty.http.client.HttpAddress;
-import org.xbib.netty.http.client.Request;
-import org.xbib.netty.http.client.transport.Transport;
-
-import java.nio.charset.StandardCharsets;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-public class ClientTest {
-
-    private static final Logger logger = Logger.getLogger(ClientTest.class.getName());
-
-    @Test
-    public void testHttp1() throws Exception {
-        Client client = new Client();
-        try {
-            Transport transport = client.newTransport(HttpAddress.http1("fl.hbz-nrw.de"));
-            transport.setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                    msg.headers().entries() +
-                    msg.content().toString(StandardCharsets.UTF_8) +
-                    " status=" + msg.status().code()));
-            transport.connect();
-            transport.awaitSettings();
-            simpleRequest(transport);
-            transport.get();
-            transport.close();
-        } finally {
-            client.shutdown();
-        }
-    }
-
-    @Test
-    public void testHttp1ParallelRequests() {
-        Client client = new Client();
-        try {
-            Request request1 = Request.builder(HttpMethod.GET)
-                    .setURL("http://fl.hbz-nrw.de").setVersion("HTTP/1.1")
-                    .build()
-                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                            msg.headers().entries() +
-                            //msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()));
-            Request request2 = Request.builder(HttpMethod.GET)
-                    .setURL("http://fl.hbz-nrw.de/app/fl/").setVersion("HTTP/1.1")
-                    .build()
-                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                            msg.headers().entries() +
-                            //msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()));
-
-            client.execute(request1);
-            client.execute(request2);
-
-        } finally {
-            client.shutdownGracefully();
-        }
-    }
-
-    @Test
-    public void testHttp2() throws Exception {
-        String host = "webtide.com";
-        Client client = new Client();
-        client.logDiagnostics(Level.INFO);
-        try {
-            Transport transport = client.newTransport(HttpAddress.http2(host));
-            transport.setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                    msg.headers().entries() +
-                    //msg.content().toString(StandardCharsets.UTF_8) +
-                    " status=" + msg.status().code()));
-            transport.setPushListener((hdrs, msg) -> logger.log(Level.INFO, "got push: " +
-                    msg.headers().entries() +
-                    //msg.content().toString(StandardCharsets.UTF_8) +
-                    " status=" + msg.status().code()));
-            transport.connect();
-            transport.awaitSettings();
-            simpleRequest(transport);
-            transport.get();
-            transport.close();
-        } finally {
-            client.shutdown();
-        }
-    }
-
-    @Test
-    public void testHttp2Request() {
-        //String url = "https://webtide.com";
-        String url = "https://http2-push.io";
-        // TODO register push announces into promises in order to wait for them all.
-        Client client = new Client();
-        try {
-            Request request = Request.builder(HttpMethod.GET)
-                    .setURL(url).setVersion("HTTP/2.0")
-                    .build()
-                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                            msg.headers().entries() +
-                            msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()))
-                    .setPushListener((hdrs, msg) -> logger.log(Level.INFO, "got push: " +
-                                    msg.headers().entries() +
-                            msg.content().toString(StandardCharsets.UTF_8))
-                    );
-            client.execute(request).get();
-
-        } finally {
-            client.shutdownGracefully();
-        }
-    }
-
-    @Test
-    public void testHttp2TwoRequestsOnSameConnection() {
-        Client client = new Client();
-        try {
-            Request request1 = Request.builder(HttpMethod.GET)
-                    .setURL("https://webtide.com").setVersion("HTTP/2.0")
-                    .build()
-                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                            msg.headers().entries() +
-                            //msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()))
-                    .setPushListener((hdrs, msg) -> logger.log(Level.INFO, "got push: " +
-                            msg.headers().entries()
-                            //msg.content().toString(StandardCharsets.UTF_8))
-                            ));
-
-            Request request2 = Request.builder(HttpMethod.GET)
-                    .setURL("https://webtide.com/why-choose-jetty/").setVersion("HTTP/2.0")
-                    .build()
-                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                            msg.headers().entries() +
-                            //msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()))
-                    .setPushListener((hdrs, msg) -> logger.log(Level.INFO, "got push: " +
-                            msg.headers().entries() +
-                            //msg.content().toString(StandardCharsets.UTF_8) +
-                            " status=" + msg.status().code()));
-
-            client.execute(request1).execute(request2);
-
-        } finally {
-            client.shutdownGracefully();
-        }
-    }
-
-    @Test
-    public void testTwoTransports() throws Exception {
-        Client client = Client.builder().enableDebug().build();
-        try {
-            Transport transport = client.newTransport(HttpAddress.http1("xbib.org"));
-            transport.setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                    msg.content().toString(StandardCharsets.UTF_8)));
-            transport.connect();
-            transport.awaitSettings();
-            simpleRequest(transport);
-            transport.get();
-            transport.close();
-
-            transport = client.newTransport(HttpAddress.http2("google.com"));
-            transport.setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
-                    msg.content().toString(StandardCharsets.UTF_8)));
-            transport.connect();
-            transport.awaitSettings();
-            simpleRequest(transport);
-            transport.get();
-            transport.close();
-        } finally {
-            client.shutdown();
-        }
-    }
-
-    private void simpleRequest(Transport transport) {
-        transport.execute(Request.builder(HttpMethod.GET)
-                .setVersion(transport.httpAddress().getVersion())
-                .setURL(transport.httpAddress().base()).build());
-    }
-
-}

src/test/java/org/xbib/netty/http/client/test/CompletableFutureTest.java

@@ -5,6 +5,7 @@ import org.junit.Test;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.Request;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Function;
@@ -19,23 +20,28 @@ public class CompletableFutureTest {
      * Get some weird content from one URL and post it to another URL, by composing completable futures.
      */
     @Test
-    public void testComposeCompletableFutures() {
+    public void testComposeCompletableFutures() throws IOException {
         Client client = new Client();
         try {
             final Function<FullHttpResponse, String> httpResponseStringFunction = response ->
                     response.content().toString(StandardCharsets.UTF_8);
             Request request = Request.get()
-                    .setURL("http://alkmene.hbz-nrw.de/repository/org/xbib/content/2.0.0-SNAPSHOT/maven-metadata-local.xml")
+                    .url("http://alkmene.hbz-nrw.de/repository/org/xbib/content/2.0.0-SNAPSHOT/maven-metadata-local.xml")
                     .build();
             CompletableFuture<String> completableFuture = client.execute(request, httpResponseStringFunction)
                     .exceptionally(Throwable::getMessage)
                     .thenCompose(content -> {
                         logger.log(Level.INFO, content);
                         // POST is not allowed, we don't care
+                        try {
                             return client.execute(Request.post()
-                                .setURL("http://google.com/")
+                                    .url("http://google.com/")
-                                .addParam("query", content)
+                                    .addParameter("query", content)
                                     .build(), httpResponseStringFunction);
+                        } catch (IOException e) {
+                            logger.log(Level.WARNING, e.getMessage(), e);
+                            return null;
+                        }
                     });
             String result = completableFuture.join();
             logger.log(Level.INFO, "completablefuture result = " + result);

src/test/java/org/xbib/netty/http/client/test/ConscryptTest.java

@@ -5,6 +5,7 @@ import org.junit.Test;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.Request;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -14,7 +15,7 @@ public class ConscryptTest extends LoggingBase {
     private static final Logger logger = Logger.getLogger("");
 
     @Test
-    public void testConscrypt() {
+    public void testConscrypt() throws IOException {
         Client client = Client.builder()
                 .enableDebug()
                 .setJdkSslProvider()
@@ -23,10 +24,9 @@ public class ConscryptTest extends LoggingBase {
         logger.log(Level.INFO, client.getClientConfig().toString());
         try {
             Request request = Request.get()
-                    .setURL("https://fl-test.hbz-nrw.de")
+                    .url("https://fl-test.hbz-nrw.de")
                     .setVersion("HTTP/2.0")
                     .build()
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e))
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status()

src/test/java/org/xbib/netty/http/client/test/CookieSetterHttpBinTest.java

@@ -4,15 +4,16 @@ import org.junit.Test;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.Request;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
  */
-public class HttpBinTest extends LoggingBase {
+public class CookieSetterHttpBinTest extends LoggingBase {
 
-    private static final Logger logger = Logger.getLogger(HttpBinTest.class.getName());
+    private static final Logger logger = Logger.getLogger(CookieSetterHttpBinTest.class.getName());
 
     /**
      * Test httpbin.org "Set-Cookie:" header after redirection of URL.
@@ -28,15 +29,14 @@ public class HttpBinTest extends LoggingBase {
      * @throws Exception
      */
     @Test
-    public void testHttpBinCookies() {
+    public void testHttpBinCookies() throws IOException {
         Client client = new Client();
         try {
             Request request = Request.get()
-                    .setURL("http://httpbin.org/cookies/set?name=value")
+                    .url("http://httpbin.org/cookies/set?name=value")
                     .build()
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e))
+                    .setCookieListener(cookie -> logger.log(Level.INFO, "this is the cookie: " + cookie.toString()))
-                    .setCookieListener(cookie -> logger.log(Level.INFO, "this is the cookie " + cookie.toString()))
+                    .setHeadersListener(headers -> logger.log(Level.INFO, "headers = " + headers.entries().toString()))
-                    .setHeadersListener(headers -> logger.log(Level.INFO, headers.toString()))
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);

src/test/java/org/xbib/netty/http/client/test/ElasticsearchTest.java

@@ -6,6 +6,7 @@ import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.Request;
 import org.xbib.netty.http.client.transport.Transport;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
@@ -21,17 +22,16 @@ public class ElasticsearchTest extends LoggingBase {
     private static final Logger logger = Logger.getLogger(ElasticsearchTest.class.getName());
 
     @Test
-    public void testElasticsearchCreateDocument() {
+    public void testElasticsearchCreateDocument() throws IOException {
         Client client = new Client();
         try {
-            Request request = Request.put().setURL("http://localhost:9200/test/test/1")
+            Request request = Request.put().url("http://localhost:9200/test/test/1")
                     .json("{\"text\":\"Hello World\"}")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
-                    })
+                    });
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e));
             client.execute(request);
         } finally {
             client.shutdownGracefully();
@@ -39,17 +39,16 @@ public class ElasticsearchTest extends LoggingBase {
     }
 
     @Test
-    public void testElasticsearchMatchQuery() {
+    public void testElasticsearchMatchQuery() throws IOException {
         Client client = new Client();
         try {
-            Request request = Request.post().setURL("http://localhost:9200/test/_search")
+            Request request = Request.post().url("http://localhost:9200/test/_search")
                     .json("{\"query\":{\"match\":{\"text\":\"Hello World\"}}}")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
-                    })
+                    });
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e));
             client.execute(request).get();
         } finally {
             client.shutdownGracefully();
@@ -57,7 +56,7 @@ public class ElasticsearchTest extends LoggingBase {
     }
 
     @Test
-    public void testElasticsearchConcurrent() {
+    public void testElasticsearchConcurrent() throws IOException {
         Client client = Client.builder().setReadTimeoutMillis(20000).build();
         int max = 1000;
         try {
@@ -78,15 +77,14 @@ public class ElasticsearchTest extends LoggingBase {
 
     private Request newRequest() {
         return Request.post()
-                .setURL("http://localhost:9200/test/_search")
+                .url("http://localhost:9200/test/_search")
                 .json("{\"query\":{\"match\":{\"text\":\"Hello World\"}}}")
                 .addHeader("connection", "keep-alive")
                 .build()
                 .setResponseListener(fullHttpResponse ->
                     logger.log(Level.FINE, "status = " + fullHttpResponse.status() +
                             " counter = " + count.incrementAndGet() +
-                            " response body = " + fullHttpResponse.content().toString(StandardCharsets.UTF_8)))
+                            " response body = " + fullHttpResponse.content().toString(StandardCharsets.UTF_8)));
-                .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e));
     }
 
     private final AtomicInteger count = new AtomicInteger();

src/test/java/org/xbib/netty/http/client/test/Http1Test.java

@@ -0,0 +1,76 @@
+package org.xbib.netty.http.client.test;
+
+import io.netty.handler.codec.http.HttpMethod;
+import org.junit.Test;
+import org.xbib.netty.http.client.Client;
+import org.xbib.netty.http.client.Request;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Http1Test {
+
+    private static final Logger logger = Logger.getLogger(Http1Test.class.getName());
+
+    @Test
+    public void testHttp1() throws Exception {
+        Client client = new Client();
+        try {
+            Request request = Request.get().url("http://fl.hbz-nrw.de").build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+            client.execute(request).get();
+        } finally {
+            client.shutdown();
+        }
+    }
+
+    @Test
+    public void testHttp1ParallelRequests() throws IOException {
+        Client client = new Client();
+        try {
+            Request request1 = Request.builder(HttpMethod.GET)
+                    .url("http://fl.hbz-nrw.de").setVersion("HTTP/1.1")
+                    .build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            //msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+            Request request2 = Request.builder(HttpMethod.GET)
+                    .url("http://fl.hbz-nrw.de/app/fl/").setVersion("HTTP/1.1")
+                    .build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            //msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+
+            client.execute(request1);
+            client.execute(request2);
+
+        } finally {
+            client.shutdownGracefully();
+        }
+    }
+
+    @Test
+    public void testTwoTransports() throws Exception {
+        Client client = Client.builder().enableDebug().build();
+        try {
+            Request request1 = Request.get().url("http://xbib.org").build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.content().toString(StandardCharsets.UTF_8)));
+            client.execute(request1).get();
+
+            Request request2 = Request.get().url("https://google.com").setVersion("HTTP/2.0").build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.content().toString(StandardCharsets.UTF_8)));
+            client.execute(request2).get();
+        } finally {
+            client.shutdown();
+        }
+    }
+}

src/test/java/org/xbib/netty/http/client/test/Http2Test.java

@@ -0,0 +1,104 @@
+package org.xbib.netty.http.client.test;
+
+import io.netty.handler.codec.http.HttpMethod;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.xbib.netty.http.client.Client;
+import org.xbib.netty.http.client.Request;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Http2Test {
+
+    private static final Logger logger = Logger.getLogger(Http2Test.class.getName());
+
+    /**
+     */
+    @Test
+    public void testAkamai() throws IOException {
+        Client client = Client.builder().enableDebug().build();
+        try {
+            Request request = Request.get()
+                    .url("https://http2.akamai.com/demo/h2_demo_frame.html")
+                    //.url("https://http2.akamai.com/")
+                    .setVersion("HTTP/2.0")
+                    .build()
+                    .setResponseListener(fullHttpResponse -> {
+                        String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
+                        logger.log(Level.INFO, "status = " + fullHttpResponse.status()
+                                + " response body = " + response);
+                    });
+            client.execute(request).get();
+        } finally {
+            client.shutdownGracefully();
+        }
+    }
+
+    @Test
+    public void testWebtide() throws Exception {
+        Client client = Client.builder().enableDebug().build();
+        client.logDiagnostics(Level.INFO);
+        try {
+            Request request = Request.get().url("https://webtide.com").setVersion("HTTP/2.0").build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                    msg.headers().entries() +
+                    //msg.content().toString(StandardCharsets.UTF_8) +
+                    " status=" + msg.status().code()));
+            client.execute(request).get();
+        } finally {
+            client.shutdown();
+        }
+    }
+
+    @Test
+    public void testHttp2PushIO() throws IOException {
+        //String url = "https://webtide.com";
+        String url = "https://http2-push.io";
+        // TODO register push announces into promises in order to wait for them all.
+        Client client = Client.builder().enableDebug().build();
+        try {
+            Request request = Request.builder(HttpMethod.GET)
+                    .url(url).setVersion("HTTP/2.0")
+                    .build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+            client.execute(request).get();
+
+        } finally {
+            client.shutdownGracefully();
+        }
+    }
+
+    @Test
+    public void testWebtideTwoRequestsOnSameConnection() {
+        Client client = new Client();
+        try {
+            Request request1 = Request.builder(HttpMethod.GET)
+                    .url("https://webtide.com").setVersion("HTTP/2.0")
+                    .build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            //msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+
+            Request request2 = Request.builder(HttpMethod.GET)
+                    .url("https://webtide.com/why-choose-jetty/").setVersion("HTTP/2.0")
+                    .build()
+                    .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
+                            msg.headers().entries() +
+                            //msg.content().toString(StandardCharsets.UTF_8) +
+                            " status=" + msg.status().code()));
+
+            client.execute(request1).execute(request2);
+        } catch (IOException e) {
+            //
+        } finally {
+            client.shutdownGracefully();
+        }
+    }
+}

src/test/java/org/xbib/netty/http/client/test/RequestBuilderTest.java

@@ -0,0 +1,19 @@
+package org.xbib.netty.http.client.test;
+
+import io.netty.handler.codec.http.HttpMethod;
+import org.junit.Test;
+import org.xbib.netty.http.client.Request;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class RequestBuilderTest {
+
+    private static final Logger logger = Logger.getLogger(RequestBuilderTest.class.getName());
+
+    @Test
+    public void testSimpleRequest() {
+        Request request = Request.builder(HttpMethod.GET).build();
+        logger.log(Level.INFO, request.toString());
+    }
+}

src/test/java/org/xbib/netty/http/client/test/URITest.java

@@ -25,13 +25,13 @@ public class URITest {
     @Test
     public void testRequestURIs() {
         RequestBuilder httpRequestBuilder = Request.get();
-        httpRequestBuilder.setURL("https://localhost").path("/path");
+        httpRequestBuilder.url("https://localhost").uri("/path");
         assertEquals("/path", httpRequestBuilder.build().relativeUri());
-        httpRequestBuilder.path("/foobar");
+        httpRequestBuilder.uri("/foobar");
         assertEquals("/foobar", httpRequestBuilder.build().relativeUri());
-        httpRequestBuilder.path("/path1?a=b");
+        httpRequestBuilder.uri("/path1?a=b");
         assertEquals("/path1?a=b", httpRequestBuilder.build().relativeUri());
-        httpRequestBuilder.path("/path2?c=d");
+        httpRequestBuilder.uri("/path2?c=d");
         assertEquals("/path2?c=d", httpRequestBuilder.build().relativeUri());
     }
 }

src/test/java/org/xbib/netty/http/client/test/XbibTest.java

@@ -5,8 +5,8 @@ import io.netty.handler.proxy.HttpProxyHandler;
 import org.junit.Test;
 import org.xbib.netty.http.client.Client;
 import org.xbib.netty.http.client.Request;
-import org.xbib.netty.http.client.test.LoggingBase;
 
+import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import java.util.concurrent.CompletableFuture;
@@ -19,10 +19,10 @@ public class XbibTest extends LoggingBase {
     private static final Logger logger = Logger.getLogger("");
 
     @Test
-    public void testXbibOrgWithDefaults() {
+    public void testXbibOrgWithDefaults() throws IOException {
         Client client = new Client();
         try {
-            Request request = Request.get().setURL("http://xbib.org")
+            Request request = Request.get().url("http://xbib.org")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
@@ -35,21 +35,28 @@ public class XbibTest extends LoggingBase {
     }
 
     @Test
-    public void testXbibOrgWithCompletableFuture() {
+    public void testXbibOrgWithCompletableFuture() throws IOException {
         Client httpClient = Client.builder()
                 .setTcpNodelay(true)
                 .build();
         try {
             final Function<FullHttpResponse, String> httpResponseStringFunction =
                     response -> response.content().toString(StandardCharsets.UTF_8);
-            Request request = Request.get().setURL("http://xbib.org")
+            Request request = Request.get().url("http://xbib.org")
                     .build();
             final CompletableFuture<String> completableFuture = httpClient.execute(request, httpResponseStringFunction)
                     .exceptionally(Throwable::getMessage)
-                    .thenCompose(content -> httpClient.execute(Request.post()
+                    .thenCompose(content -> {
-                            .setURL("http://google.de")
+                        try {
-                            .addParam("query", content)
+                            return httpClient.execute(Request.post()
-                            .build(), httpResponseStringFunction));
+                                    .url("http://google.de")
+                                    .addParameter("query", content)
+                                    .build(), httpResponseStringFunction);
+                        } catch (IOException e) {
+                            logger.log(Level.WARNING, e.getMessage(), e);
+                            return null;
+                        }
+                    });
             String result = completableFuture.join();
             logger.info("result = " + result);
         } finally {
@@ -58,7 +65,7 @@ public class XbibTest extends LoggingBase {
     }
 
     @Test
-    public void testXbibOrgWithProxy() {
+    public void testXbibOrgWithProxy() throws IOException {
         Client httpClient = Client.builder()
                 .setHttpProxyHandler(new HttpProxyHandler(new InetSocketAddress("80.241.223.251", 8080)))
                 .setConnectTimeoutMillis(30000)
@@ -66,13 +73,12 @@ public class XbibTest extends LoggingBase {
                 .build();
         try {
             httpClient.execute(Request.get()
-                    .setURL("http://xbib.org")
+                    .url("http://xbib.org")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
-                    })
+                    }))
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e)))
                     .get();
         } finally {
             httpClient.shutdownGracefully();
@@ -80,19 +86,18 @@ public class XbibTest extends LoggingBase {
     }
 
     @Test
-    public void testXbibOrgWithVeryShortReadTimeout() {
+    public void testXbibOrgWithVeryShortReadTimeout() throws IOException {
         Client httpClient = Client.builder()
                 .setReadTimeoutMillis(50)
                 .build();
         try {
             httpClient.execute(Request.get()
-                    .setURL("http://xbib.org")
+                    .url("http://xbib.org")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
-                    })
+                    }))
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e)))
                     .get();
         } finally {
             httpClient.shutdownGracefully();
@@ -100,14 +105,13 @@ public class XbibTest extends LoggingBase {
     }
 
     @Test
-    public void testXbibTwoSequentialRequests() {
+    public void testXbibTwoSequentialRequests() throws IOException {
         Client httpClient = new Client();
         try {
             httpClient.execute(Request.get()
                     .setVersion("HTTP/1.1")
-                    .setURL("http://xbib.org")
+                    .url("http://xbib.org")
                     .build()
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e))
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
@@ -116,9 +120,8 @@ public class XbibTest extends LoggingBase {
 
             httpClient.execute(Request.get()
                     .setVersion("HTTP/1.1")
-                    .setURL("http://xbib.org")
+                    .url("http://xbib.org")
                     .build()
-                    .setExceptionListener(e -> logger.log(Level.SEVERE, e.getMessage(), e))
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
                         logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);

src/test/java/org/xbib/netty/http/client/test/pool/EpollTest.java

@@ -0,0 +1,132 @@
+package org.xbib.netty.http.client.test.pool;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import io.netty.channel.epoll.EpollSocketChannel;
+import io.netty.channel.socket.SocketChannel;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.xbib.netty.http.client.HttpAddress;
+import org.xbib.netty.http.client.pool.Pool;
+import org.xbib.netty.http.client.pool.SimpleChannelPool;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.LongAdder;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class EpollTest {
+
+    private static final Logger logger = Logger.getLogger(EpollTest.class.getName());
+
+    private static final int CONCURRENCY = 10;
+
+    private static final List<HttpAddress> NODES =
+            Collections.singletonList(HttpAddress.http1("localhost", 12345));
+
+    private static final long TEST_TIME_SECONDS = 100;
+
+    private static final int ATTEMPTS = 10_000;
+
+    private static final int FAIL_EVERY_ATTEMPT = 10;
+
+    private static final ByteBuf PAYLOAD = Unpooled.directBuffer(0x1000).writeZero(0x1000);
+
+    private MockEpollServer mockEpollServer;
+
+    private Pool<Channel> channelPool;
+
+    private EventLoopGroup eventLoopGroup;
+
+    @Before
+    public void setUp() throws Exception {
+        mockEpollServer = new MockEpollServer(12345, FAIL_EVERY_ATTEMPT);
+        Semaphore semaphore = new Semaphore(CONCURRENCY);
+        eventLoopGroup = new EpollEventLoopGroup();
+        Bootstrap bootstrap = new Bootstrap()
+            .group(eventLoopGroup)
+            .channel(EpollSocketChannel.class)
+            .handler(new ChannelInitializer<SocketChannel>() {
+                @Override
+                protected void initChannel(SocketChannel socketChannel) {
+                    socketChannel.pipeline().addLast(new DummyClientChannelHandler());
+                }
+            })
+            .option(ChannelOption.SO_KEEPALIVE, true)
+            .option(ChannelOption.SO_REUSEADDR, true)
+            .option(ChannelOption.TCP_NODELAY, true);
+        channelPool = new SimpleChannelPool<>(semaphore, NODES, bootstrap, null, 0);
+        channelPool.prepare(CONCURRENCY);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        channelPool.close();
+        eventLoopGroup.shutdownGracefully();
+        mockEpollServer.close();
+    }
+
+    @Ignore
+    @Test
+    public void testPoolEpoll() throws Exception {
+        LongAdder longAdder = new LongAdder();
+        ExecutorService executor = Executors.newFixedThreadPool(CONCURRENCY);
+        for(int i = 0; i < CONCURRENCY; i ++) {
+            executor.submit(() -> {
+                Channel channel;
+                for(int j = 0; j < ATTEMPTS; j ++) {
+                    try {
+                        while ((channel = channelPool.acquire()) == null) {
+                            Thread.sleep(1); // very short?
+                        }
+                        channel.writeAndFlush(PAYLOAD.retain()).sync();
+                        channelPool.release(channel);
+                        longAdder.increment();
+                    } catch (InterruptedException e) {
+                        break;
+                    } catch (Throwable cause) {
+                        logger.log(Level.WARNING, cause.getMessage(), cause);
+                    }
+                }
+            });
+        }
+        executor.shutdown();
+        executor.awaitTermination(TEST_TIME_SECONDS, TimeUnit.SECONDS);
+        assertTrue(executor.isTerminated());
+        assertEquals(CONCURRENCY * ATTEMPTS, longAdder.sum(),
+                2 * CONCURRENCY * ATTEMPTS / FAIL_EVERY_ATTEMPT);
+    }
+
+    class DummyClientChannelHandler extends SimpleChannelInboundHandler<Object> {
+
+        @Override
+        protected void channelRead0(ChannelHandlerContext ctx, Object msg) {
+        }
+
+        @Override
+        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+            super.exceptionCaught(ctx, cause);
+            logger.log(Level.WARNING, cause.getMessage(), cause);
+        }
+    }
+
+}

src/test/java/org/xbib/netty/http/client/test/pool/MockEpollServer.java

@@ -0,0 +1,64 @@
+package org.xbib.netty.http.client.test.pool;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import io.netty.channel.epoll.EpollServerSocketChannel;
+import io.netty.channel.socket.SocketChannel;
+
+import java.io.Closeable;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class MockEpollServer implements Closeable {
+
+    private static final Logger logger = Logger.getLogger(MockEpollServer.class.getName());
+
+    private final EventLoopGroup dispatchGroup;
+
+    private final EventLoopGroup workerGroup;
+
+    private final ChannelFuture bindFuture;
+
+    private final AtomicLong reqCounter;
+
+    public MockEpollServer(int port, int dropEveryRequest) throws InterruptedException {
+        dispatchGroup = new EpollEventLoopGroup();
+        workerGroup = new EpollEventLoopGroup();
+        reqCounter = new AtomicLong(0);
+        ServerBootstrap bootstrap = new ServerBootstrap()
+            .group(dispatchGroup, workerGroup)
+            .channel(EpollServerSocketChannel.class)
+            .childHandler(new ChannelInitializer<SocketChannel>() {
+                @Override
+                public void initChannel(SocketChannel ch) {
+                    if (dropEveryRequest > 0) {
+                        ch.pipeline().addLast(new SimpleChannelInboundHandler<Object>() {
+                            @Override
+                            protected void channelRead0(ChannelHandlerContext ctx, Object msg) {
+                                if (reqCounter.incrementAndGet() % dropEveryRequest == 0) {
+                                    Channel channel = ctx.channel();
+                                    logger.log(Level.INFO,"dropping the connection " + channel);
+                                    channel.close();
+                                }
+                            }
+                        });
+                    }
+                }
+            });
+        bindFuture = bootstrap.bind(port).sync();
+    }
+
+    @Override
+    public void close() {
+        bindFuture.channel().close();
+        workerGroup.shutdownGracefully();
+        dispatchGroup.shutdownGracefully();
+    }
+}

src/test/java/org/xbib/netty/http/client/test/pool/MockNioServer.java

@@ -0,0 +1,62 @@
+package org.xbib.netty.http.client.test.pool;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+
+import java.io.Closeable;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class MockNioServer implements Closeable {
+
+    private static final Logger logger = Logger.getLogger(MockNioServer.class.getName());
+
+    private final EventLoopGroup dispatchGroup;
+
+    private final EventLoopGroup workerGroup;
+
+    private final ChannelFuture bindFuture;
+
+    private final AtomicLong reqCounter;
+
+    public MockNioServer(int port, int dropEveryRequest) throws InterruptedException {
+        dispatchGroup = new NioEventLoopGroup();
+        workerGroup = new NioEventLoopGroup();
+        reqCounter = new AtomicLong(0);
+        ServerBootstrap bootstrap = new ServerBootstrap()
+            .group(dispatchGroup, workerGroup)
+            .channel(NioServerSocketChannel.class)
+            .childHandler(new ChannelInitializer<SocketChannel>() {
+                @Override
+                public void initChannel(SocketChannel ch) {
+                    ch.pipeline().addLast(new SimpleChannelInboundHandler<Object>() {
+                        @Override
+                        protected void channelRead0(ChannelHandlerContext ctx, Object msg) {
+                            if (reqCounter.incrementAndGet() % dropEveryRequest == 0) {
+                                Channel channel = ctx.channel();
+                                logger.log(Level.INFO, "dropping the connection " + channel);
+                                channel.close();
+                            }
+                        }
+                    });
+                }
+            });
+        bindFuture = bootstrap.bind(port).sync();
+    }
+
+    @Override
+    public void close() {
+        bindFuture.channel().close();
+        workerGroup.shutdownGracefully();
+        dispatchGroup.shutdownGracefully();
+    }
+}

src/test/java/org/xbib/netty/http/client/test/pool/NioTest.java

@@ -0,0 +1,128 @@
+package org.xbib.netty.http.client.test.pool;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.xbib.netty.http.client.HttpAddress;
+import org.xbib.netty.http.client.pool.Pool;
+import org.xbib.netty.http.client.pool.SimpleChannelPool;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.LongAdder;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class NioTest {
+
+    private static final Logger logger = Logger.getLogger(NioTest.class.getName());
+
+    private static final int CONCURRENCY = 10;
+
+    private static final List<HttpAddress> NODES =
+            Collections.singletonList(HttpAddress.http1("localhost", 12345));
+
+    private static final long TEST_TIME_SECONDS = 100;
+
+    private static final int ATTEMPTS = 10_000;
+
+    private static final int FAIL_EVERY_ATTEMPT = 10;
+
+    private static final ByteBuf PAYLOAD = Unpooled.directBuffer(0x1000).writeZero(0x1000);
+
+    private MockNioServer mockNioServer;
+
+    private Pool<Channel> channelPool;
+
+    private EventLoopGroup eventLoopGroup;
+
+    @Before
+    public void setUp() throws Exception {
+        mockNioServer = new MockNioServer(12345, FAIL_EVERY_ATTEMPT);
+        Semaphore semaphore = new Semaphore(CONCURRENCY);
+        eventLoopGroup = new NioEventLoopGroup();
+        Bootstrap bootstrap = new Bootstrap()
+            .group(eventLoopGroup)
+            .channel(NioSocketChannel.class)
+            .handler(new ChannelInitializer<SocketChannel>() {
+                @Override
+                protected void initChannel(SocketChannel socketChannel) {
+                    socketChannel.pipeline().addLast(new DummyClientChannelHandler());
+                }
+            })
+            .option(ChannelOption.SO_KEEPALIVE, true)
+            .option(ChannelOption.SO_REUSEADDR, true)
+            .option(ChannelOption.TCP_NODELAY, true);
+        channelPool = new SimpleChannelPool<>(semaphore, NODES, bootstrap, null, 0);
+        channelPool.prepare(CONCURRENCY);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        channelPool.close();
+        eventLoopGroup.shutdownGracefully();
+        mockNioServer.close();
+    }
+
+    @Test
+    public void testPoolNio() throws Exception {
+        LongAdder longAdder = new LongAdder();
+        ExecutorService executor = Executors.newFixedThreadPool(CONCURRENCY);
+        for(int i = 0; i < CONCURRENCY; i ++) {
+            executor.submit(() -> {
+                Channel channel;
+                for(int j = 0; j < ATTEMPTS; j ++) {
+                    try {
+                        while ((channel = channelPool.acquire()) == null) {
+                            Thread.sleep(1);
+                        }
+                        channel.writeAndFlush(PAYLOAD.retain()).sync();
+                        channelPool.release(channel);
+                        longAdder.increment();
+                    } catch (InterruptedException e) {
+                        break;
+                    } catch (Throwable cause) {
+                        logger.log(Level.WARNING, cause.getMessage(), cause);
+                    }
+                }
+            });
+        }
+        executor.shutdown();
+        executor.awaitTermination(TEST_TIME_SECONDS, TimeUnit.SECONDS);
+        assertTrue(executor.isTerminated());
+        assertEquals(CONCURRENCY * ATTEMPTS, longAdder.sum(),
+                2 * CONCURRENCY * ATTEMPTS / FAIL_EVERY_ATTEMPT);
+    }
+
+    class DummyClientChannelHandler extends SimpleChannelInboundHandler<Object> {
+
+        @Override
+        protected void channelRead0(ChannelHandlerContext ctx, Object msg) {
+        }
+
+        @Override
+        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+            super.exceptionCaught(ctx, cause);
+            logger.log(Level.WARNING, cause.getMessage(), cause);
+        }
+    }
+}

src/test/java/org/xbib/netty/http/client/test/pool/SimplePoolTest.java

@@ -0,0 +1,124 @@
+package org.xbib.netty.http.client.test.pool;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.channel.Channel;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.LongAdder;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import io.netty.util.AttributeKey;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.xbib.netty.http.client.HttpAddress;
+import org.xbib.netty.http.client.pool.Pool;
+import org.xbib.netty.http.client.pool.SimpleChannelPool;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(Parameterized.class)
+public class SimplePoolTest {
+
+    private static final Logger logger = Logger.getLogger(SimplePoolTest.class.getName());
+
+    private static final int TEST_STEP_TIME_SECONDS = 50;
+
+    private static final int BATCH_SIZE = 0x1000;
+
+    private int nodeCount;
+
+    private ConcurrentMap<HttpAddress, LongAdder> nodeFreq = new ConcurrentHashMap<>();
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> generateData() {
+        return Arrays.asList(new Object[][] {
+                        {1, 1},
+                        {10, 1}, {10, 2}, {10, 5}, {10, 10},
+                        {100, 1}, {100, 2}, {100, 5}, {100, 10},
+                        {1000, 1}, {1000, 2}, {1000, 5}, {1000, 10}
+                });
+    }
+
+    public SimplePoolTest(int concurrencyLevel, int nodeCount) {
+        this.nodeCount = nodeCount;
+        List<HttpAddress> nodes = new ArrayList<>();
+        for (int i = 0; i < nodeCount; i ++) {
+            nodes.add(HttpAddress.http1("localhost" + i));
+        }
+        try (Pool<Channel> pool = new SimpleChannelPool<>(new Semaphore(concurrencyLevel), nodes, new Bootstrap(),
+                        null, 0)) {
+            int n = Runtime.getRuntime().availableProcessors();
+            ExecutorService executorService = Executors.newFixedThreadPool(n);
+            for(int i = 0; i < n; i ++) {
+                executorService.submit(() -> {
+                    Thread currThread = Thread.currentThread();
+                    List<Channel> channels = new ArrayList<>(BATCH_SIZE);
+                    int j;
+                    int k;
+                    Channel channel;
+                    try {
+                        while (!currThread.isInterrupted()) {
+                            for (j = 0; j < BATCH_SIZE; j ++) {
+                                channel = pool.acquire();
+                                if (channel == null) {
+                                    break;
+                                }
+                                AttributeKey<HttpAddress> attributeKey = AttributeKey.valueOf("poolKey");
+                                nodeFreq.computeIfAbsent(channel.attr(attributeKey).get(), node -> new LongAdder()).increment();
+                                channels.add(channel);
+                            }
+                            for (k = 0; k < j; k ++) {
+                                pool.release(channels.get(k));
+                            }
+                            channels.clear();
+                        }
+                    } catch (Exception ignored) {
+                        //
+                    }
+                });
+            }
+            executorService.shutdown();
+            try {
+                executorService.awaitTermination(TEST_STEP_TIME_SECONDS, TimeUnit.SECONDS);
+            } catch (InterruptedException e) {
+                logger.log(Level.WARNING, e.getMessage(), e);
+            }
+            executorService.shutdownNow();
+        } catch (Throwable t) {
+            logger.log(Level.WARNING, t.getMessage(), t);
+        } finally {
+            long connCountSum = nodeFreq.values().stream().mapToLong(LongAdder::sum).sum();
+            logger.log(Level.INFO, "concurrency = " + concurrencyLevel + ", nodes = " + nodeCount + " -> rate: " +
+                            connCountSum / TEST_STEP_TIME_SECONDS);
+        }
+    }
+
+    @Test
+    public void testNodeFrequency() {
+        if (nodeCount > 1) {
+            long connCountSum = nodeFreq.values().stream().mapToLong(LongAdder::sum).sum();
+            long avgConnCountPerNode = connCountSum / nodeCount;
+            for (HttpAddress nodeAddr: nodeFreq.keySet()) {
+                assertTrue(nodeFreq.get(nodeAddr).sum() > 0);
+                assertEquals("Node count: " + nodeCount + ", node: " + nodeAddr
+                                + ", expected connection count: " + avgConnCountPerNode + ", actual: "
+                                + nodeFreq.get(nodeAddr).sum(),
+                        avgConnCountPerNode, nodeFreq.get(nodeAddr).sum(), 1.5 * avgConnCountPerNode);
+            }
+        } else {
+            assertTrue(true);
+        }
+    }
+}

src/test/java/org/xbib/netty/http/client/test/retry/ExponentialBackOffTest.java

@@ -0,0 +1,156 @@
+package org.xbib.netty.http.client.test.retry;
+
+import org.junit.Test;
+import org.xbib.netty.http.client.retry.BackOff;
+import org.xbib.netty.http.client.retry.ExponentialBackOff;
+import org.xbib.netty.http.client.retry.NanoClock;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests {@link ExponentialBackOff}.
+ */
+public class ExponentialBackOffTest {
+
+    @Test
+    public void testConstructor() {
+        ExponentialBackOff backOffPolicy = new ExponentialBackOff();
+        assertEquals(ExponentialBackOff.DEFAULT_INITIAL_INTERVAL_MILLIS,
+                backOffPolicy.getInitialIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_INITIAL_INTERVAL_MILLIS,
+                backOffPolicy.getCurrentIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_RANDOMIZATION_FACTOR,
+                backOffPolicy.getRandomizationFactor(), 1);
+        assertEquals(ExponentialBackOff.DEFAULT_MULTIPLIER, backOffPolicy.getMultiplier(), 1);
+        assertEquals(
+                ExponentialBackOff.DEFAULT_MAX_INTERVAL_MILLIS, backOffPolicy.getMaxIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_MAX_ELAPSED_TIME_MILLIS,
+                backOffPolicy.getMaxElapsedTimeMillis());
+    }
+
+    @Test
+    public void testBuilder() {
+        ExponentialBackOff backOffPolicy = new ExponentialBackOff.Builder().build();
+        assertEquals(ExponentialBackOff.DEFAULT_INITIAL_INTERVAL_MILLIS,
+                backOffPolicy.getInitialIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_INITIAL_INTERVAL_MILLIS,
+                backOffPolicy.getCurrentIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_RANDOMIZATION_FACTOR,
+                backOffPolicy.getRandomizationFactor(), 1);
+        assertEquals(ExponentialBackOff.DEFAULT_MULTIPLIER, backOffPolicy.getMultiplier(), 1);
+        assertEquals(ExponentialBackOff.DEFAULT_MAX_INTERVAL_MILLIS, backOffPolicy.getMaxIntervalMillis());
+        assertEquals(ExponentialBackOff.DEFAULT_MAX_ELAPSED_TIME_MILLIS,
+                backOffPolicy.getMaxElapsedTimeMillis());
+
+        int testInitialInterval = 1;
+        double testRandomizationFactor = 0.1;
+        double testMultiplier = 5.0;
+        int testMaxInterval = 10;
+        int testMaxElapsedTime = 900000;
+
+        backOffPolicy = new ExponentialBackOff.Builder()
+                .setInitialIntervalMillis(testInitialInterval)
+                .setRandomizationFactor(testRandomizationFactor)
+                .setMultiplier(testMultiplier)
+                .setMaxIntervalMillis(testMaxInterval)
+                .setMaxElapsedTimeMillis(testMaxElapsedTime)
+                .build();
+        assertEquals(testInitialInterval, backOffPolicy.getInitialIntervalMillis());
+        assertEquals(testInitialInterval, backOffPolicy.getCurrentIntervalMillis());
+        assertEquals(testRandomizationFactor, backOffPolicy.getRandomizationFactor(), 1);
+        assertEquals(testMultiplier, backOffPolicy.getMultiplier(), 1);
+        assertEquals(testMaxInterval, backOffPolicy.getMaxIntervalMillis());
+        assertEquals(testMaxElapsedTime, backOffPolicy.getMaxElapsedTimeMillis());
+    }
+
+    @Test
+    public void testBackOff() {
+        int testInitialInterval = 500;
+        double testRandomizationFactor = 0.1;
+        double testMultiplier = 2.0;
+        int testMaxInterval = 5000;
+        int testMaxElapsedTime = 900000;
+
+        ExponentialBackOff backOffPolicy = new ExponentialBackOff.Builder()
+                .setInitialIntervalMillis(testInitialInterval)
+                .setRandomizationFactor(testRandomizationFactor)
+                .setMultiplier(testMultiplier)
+                .setMaxIntervalMillis(testMaxInterval)
+                .setMaxElapsedTimeMillis(testMaxElapsedTime)
+                .build();
+        int[] expectedResults = {500, 1000, 2000, 4000, 5000, 5000, 5000, 5000, 5000, 5000};
+        for (int expected : expectedResults) {
+            assertEquals(expected, backOffPolicy.getCurrentIntervalMillis());
+            // Assert that the next back off falls in the expected range.
+            int minInterval = (int) (expected - (testRandomizationFactor * expected));
+            int maxInterval = (int) (expected + (testRandomizationFactor * expected));
+            long actualInterval = backOffPolicy.nextBackOffMillis();
+            assertTrue(minInterval <= actualInterval && actualInterval <= maxInterval);
+        }
+    }
+
+    @Test
+    public void testGetRandomizedInterval() {
+        // 33% chance of being 1.
+        assertEquals(1, ExponentialBackOff.getRandomValueFromInterval(0.5, 0, 2));
+        assertEquals(1, ExponentialBackOff.getRandomValueFromInterval(0.5, 0.33, 2));
+        // 33% chance of being 2.
+        assertEquals(2, ExponentialBackOff.getRandomValueFromInterval(0.5, 0.34, 2));
+        assertEquals(2, ExponentialBackOff.getRandomValueFromInterval(0.5, 0.66, 2));
+        // 33% chance of being 3.
+        assertEquals(3, ExponentialBackOff.getRandomValueFromInterval(0.5, 0.67, 2));
+        assertEquals(3, ExponentialBackOff.getRandomValueFromInterval(0.5, 0.99, 2));
+    }
+
+    @Test
+    public void testGetElapsedTimeMillis() {
+        ExponentialBackOff backOffPolicy = new ExponentialBackOff.Builder().setNanoClock(new MyNanoClock()).build();
+        long elapsedTimeMillis = backOffPolicy.getElapsedTimeMillis();
+        assertEquals("elapsedTimeMillis=" + elapsedTimeMillis, 1000, elapsedTimeMillis);
+    }
+
+    @Test
+    public void testMaxElapsedTime() {
+        ExponentialBackOff backOffPolicy =
+                new ExponentialBackOff.Builder().setNanoClock(new MyNanoClock(10000)).build();
+        assertTrue(backOffPolicy.nextBackOffMillis() != BackOff.STOP);
+        // Change the currentElapsedTimeMillis to be 0 ensuring that the elapsed time will be greater
+        // than the max elapsed time.
+        backOffPolicy.setStartTimeNanos(0);
+        assertEquals(BackOff.STOP, backOffPolicy.nextBackOffMillis());
+    }
+
+    @Test
+    public void testBackOffOverflow() {
+        int testInitialInterval = Integer.MAX_VALUE / 2;
+        double testMultiplier = 2.1;
+        int testMaxInterval = Integer.MAX_VALUE;
+        ExponentialBackOff backOffPolicy = new ExponentialBackOff.Builder()
+                .setInitialIntervalMillis(testInitialInterval)
+                .setMultiplier(testMultiplier)
+                .setMaxIntervalMillis(testMaxInterval)
+                .build();
+        backOffPolicy.nextBackOffMillis();
+        // Assert that when an overflow is possible the current interval is set to the max interval.
+        assertEquals(testMaxInterval, backOffPolicy.getCurrentIntervalMillis());
+    }
+
+    static class MyNanoClock implements NanoClock {
+
+        private int i = 0;
+        private long startSeconds;
+
+        MyNanoClock() {
+        }
+
+        MyNanoClock(long startSeconds) {
+            this.startSeconds = startSeconds;
+        }
+
+        public long nanoTime() {
+            return (startSeconds + i++) * 1000000000;
+        }
+    }
+
+}

src/test/java/org/xbib/netty/http/client/test/retry/MockBackOff.java

@@ -0,0 +1,75 @@
+package org.xbib.netty.http.client.test.retry;
+
+import org.xbib.netty.http.client.retry.BackOff;
+
+import java.io.IOException;
+
+/**
+ * Mock for {@link BackOff} that always returns a fixed number.
+ *
+ * <p>
+ * Implementation is not thread-safe.
+ * </p>
+ *
+ */
+public class MockBackOff implements BackOff {
+
+    /** Fixed back-off milliseconds. */
+    private long backOffMillis;
+
+    /** Maximum number of tries before returning {@link #STOP}. */
+    private int maxTries = 10;
+
+    /** Number of tries so far. */
+    private int numTries;
+
+    public void reset() throws IOException {
+        numTries = 0;
+    }
+
+    public long nextBackOffMillis() throws IOException {
+        if (numTries >= maxTries || backOffMillis == STOP) {
+            return STOP;
+        }
+        numTries++;
+        return backOffMillis;
+    }
+
+    /**
+     * Sets the fixed back-off milliseconds (defaults to {@code 0}).
+     *
+     * <p>
+     * Overriding is only supported for the purpose of calling the super implementation and changing
+     * the return type, but nothing else.
+     * </p>
+     */
+    public MockBackOff setBackOffMillis(long backOffMillis) {
+        //Preconditions.checkArgument(backOffMillis == STOP || backOffMillis >= 0);
+        this.backOffMillis = backOffMillis;
+        return this;
+    }
+
+    /**
+     * Sets the maximum number of tries before returning {@link #STOP} (defaults to {@code 10}).
+     *
+     * <p>
+     * Overriding is only supported for the purpose of calling the super implementation and changing
+     * the return type, but nothing else.
+     * </p>
+     */
+    public MockBackOff setMaxTries(int maxTries) {
+        //Preconditions.checkArgument(maxTries >= 0);
+        this.maxTries = maxTries;
+        return this;
+    }
+
+    /** Returns the maximum number of tries before returning {@link #STOP}. */
+    public final int getMaxTries() {
+        return numTries;
+    }
+
+    /** Returns the number of tries so far. */
+    public final int getNumberOfTries() {
+        return numTries;
+    }
+}

src/test/java/org/xbib/netty/http/client/test/retry/MockBackOffTest.java

@@ -0,0 +1,27 @@
+package org.xbib.netty.http.client.test.retry;
+
+import org.junit.Test;
+import org.xbib.netty.http.client.retry.BackOff;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests {@link MockBackOff}.
+ */
+public class MockBackOffTest {
+
+    @Test
+    public void testNextBackOffMillis() throws IOException {
+        subtestNextBackOffMillis(0, new MockBackOff());
+        subtestNextBackOffMillis(BackOff.STOP, new MockBackOff().setBackOffMillis(BackOff.STOP));
+        subtestNextBackOffMillis(42, new MockBackOff().setBackOffMillis(42));
+    }
+
+    private void subtestNextBackOffMillis(long expectedValue, BackOff backOffPolicy) throws IOException {
+        for (int i = 0; i < 10; i++) {
+            assertEquals(expectedValue, backOffPolicy.nextBackOffMillis());
+        }
+    }
+}