add pool implementation, back-off for retry, cleaning up

build.gradle

@@ -2,6 +2,7 @@ import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter
 
 plugins {
+    id "com.github.spotbugs" version "1.6.1"
     id "org.sonarqube" version "2.6.1"
     id "io.codearte.nexus-staging" version "0.11.0"
     id "org.xbib.gradle.plugin.asciidoctor" version "1.6.0.0"
@@ -23,10 +24,10 @@ printf "Date: %s\nHost: %s\nOS: %s %s %s\nJVM: %s %s %s %s\nGradle: %s Groovy: %
 apply plugin: 'java'
 apply plugin: 'maven'
 apply plugin: 'signing'
+apply plugin: "com.github.spotbugs"
 apply plugin: "io.codearte.nexus-staging"
 apply plugin: 'org.xbib.gradle.plugin.asciidoctor'
 
-
 configurations {
     alpnagent
     asciidoclet
@@ -37,7 +38,7 @@ 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')}"
+    compile "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')}"
@@ -66,7 +67,7 @@ test {
         jvmArgs "-javaagent:" + configurations.alpnagent.asPath
     }
     testLogging {
-        showStandardStreams = false
+        showStandardStreams = true
         exceptionFormat = 'full'
     }
 }
@@ -121,5 +122,109 @@ if (project.hasProperty('signing.keyId')) {
     }
 }
 
-apply from: 'gradle/ext.gradle'
+
-apply from: 'gradle/publish.gradle'
+spotbugs {
+    effort = "max"
+    reportLevel = "low"
+    //includeFilter = file("findbugs-exclude.xml")
+}
+
+tasks.withType(com.github.spotbugs.SpotBugsTask) {
+    ignoreFailures = true
+    reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+}
+
+sonarqube {
+    properties {
+        property "sonar.projectName", "${project.group} ${project.name}"
+        property "sonar.sourceEncoding", "UTF-8"
+        property "sonar.tests", "src/test/java"
+        property "sonar.scm.provider", "git"
+        property "sonar.junit.reportsPath", "build/test-results/test/"
+    }
+}
+
+ext {
+    user = 'jprante'
+    name = 'netty-http-client'
+    description = 'A java client for Elasticsearch'
+    scmUrl = 'https://github.com/' + user + '/' + name
+    scmConnection = 'scm:git:git://github.com/' + user + '/' + name + '.git'
+    scmDeveloperConnection = 'scm:git:git://github.com/' + user + '/' + name + '.git'
+}
+
+
+task xbibUpload(type: Upload) {
+    group = 'publish'
+    configuration = configurations.archives
+    uploadDescriptor = true
+    repositories {
+        if (project.hasProperty("xbibUsername")) {
+            mavenDeployer {
+                configuration = configurations.wagon
+                repository(url: 'sftp://xbib.org/repository') {
+                    authentication(userName: xbibUsername, privateKey: xbibPrivateKey)
+                }
+            }
+        }
+    }
+}
+
+task sonaTypeUpload(type: Upload) {
+    group = 'publish'
+    configuration = configurations.archives
+    uploadDescriptor = true
+    repositories {
+        if (project.hasProperty('ossrhUsername')) {
+            mavenDeployer {
+                beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
+                repository(url: 'https://oss.sonatype.org/service/local/staging/deploy/maven2') {
+                    authentication(userName: ossrhUsername, password: ossrhPassword)
+                }
+                snapshotRepository(url: 'https://oss.sonatype.org/content/repositories/snapshots') {
+                    authentication(userName: ossrhUsername, password: ossrhPassword)
+                }
+                pom.project {
+                    groupId project.group
+                    artifactId project.name
+                    version project.version
+                    name project.name
+                    description description
+                    packaging 'jar'
+                    inceptionYear '2012'
+                    url scmUrl
+                    organization {
+                        name 'xbib'
+                        url 'http://xbib.org'
+                    }
+                    developers {
+                        developer {
+                            id user
+                            name 'Jörg Prante'
+                            email 'joergprante@gmail.com'
+                            url 'https://github.com/jprante'
+                        }
+                    }
+                    scm {
+                        url scmUrl
+                        connection scmConnection
+                        developerConnection scmDeveloperConnection
+                    }
+                    licenses {
+                        license {
+                            name 'The Apache License, Version 2.0'
+                            url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+nexusStaging {
+    packageGroup = "org.xbib"
+}

gradle.properties

@@ -1,8 +1,8 @@
 group = org.xbib
 name = netty-http-client
-version = 4.1.16.0
+version = 4.1.22.2
 
-netty.version = 4.1.16.Final
+netty.version = 4.1.22.Final
 tcnative.version = 2.0.7.Final
 conscrypt.version = 1.0.1
 xbib-net-url.version = 1.1.0

gradle/ext.gradle

@@ -1,9 +0,0 @@
-
-ext {
-    user = 'jprante'
-    name = 'netty-http-client'
-    description = 'A java client for Elasticsearch'
-    scmUrl = 'https://github.com/' + user + '/' + name
-    scmConnection = 'scm:git:git://github.com/' + user + '/' + name + '.git'
-    scmDeveloperConnection = 'scm:git:git://github.com/' + user + '/' + name + '.git'
-}

gradle/publish.gradle

@@ -1,72 +0,0 @@
-
-task xbibUpload(type: Upload) {
-    group = 'publish'
-    configuration = configurations.archives
-    uploadDescriptor = true
-    repositories {
-        if (project.hasProperty("xbibUsername")) {
-            mavenDeployer {
-                configuration = configurations.wagon
-                repository(url: 'sftp://xbib.org/repository') {
-                    authentication(userName: xbibUsername, privateKey: xbibPrivateKey)
-                }
-            }
-        }
-    }
-}
-
-task sonaTypeUpload(type: Upload) {
-    group = 'publish'
-    configuration = configurations.archives
-    uploadDescriptor = true
-    repositories {
-        if (project.hasProperty('ossrhUsername')) {
-            mavenDeployer {
-                beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
-                repository(url: 'https://oss.sonatype.org/service/local/staging/deploy/maven2') {
-                    authentication(userName: ossrhUsername, password: ossrhPassword)
-                }
-                snapshotRepository(url: 'https://oss.sonatype.org/content/repositories/snapshots') {
-                    authentication(userName: ossrhUsername, password: ossrhPassword)
-                }
-                pom.project {
-                    groupId project.group
-                    artifactId project.name
-                    version project.version
-                    name project.name
-                    description description
-                    packaging 'jar'
-                    inceptionYear '2012'
-                    url scmUrl
-                    organization {
-                        name 'xbib'
-                        url 'http://xbib.org'
-                    }
-                    developers {
-                        developer {
-                            id user
-                            name 'Jörg Prante'
-                            email 'joergprante@gmail.com'
-                            url 'https://github.com/jprante'
-                        }
-                    }
-                    scm {
-                        url scmUrl
-                        connection scmConnection
-                        developerConnection scmDeveloperConnection
-                    }
-                    licenses {
-                        license {
-                            name 'The Apache License, Version 2.0'
-                            url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-nexusStaging {
-    packageGroup = "org.xbib"
-}

gradle/sonarqube.gradle

@@ -1,39 +0,0 @@
-tasks.withType(FindBugs) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = false
-        html.enabled = true
-    }
-}
-tasks.withType(Pmd) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = true
-        html.enabled = true
-    }
-}
-tasks.withType(Checkstyle) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = true
-        html.enabled = true
-    }
-}
-
-jacocoTestReport {
-    reports {
-        xml.enabled = true
-        csv.enabled = false
-    }
-}
-
-sonarqube {
-    properties {
-        property "sonar.projectName", "${project.group} ${project.name}"
-        property "sonar.sourceEncoding", "UTF-8"
-        property "sonar.tests", "src/test/java"
-        property "sonar.scm.provider", "git"
-        property "sonar.java.coveragePlugin", "jacoco"
-        property "sonar.junit.reportsPath", "build/test-results/test/"
-    }
-}

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

@@ -2,38 +2,54 @@ package org.xbib.netty.http.client;
 
 import io.netty.bootstrap.Bootstrap;
 import io.netty.buffer.ByteBufAllocator;
-import io.netty.buffer.PooledByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import io.netty.channel.epoll.EpollSocketChannel;
 import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.pool.ChannelPoolHandler;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.Http2SecurityUtil;
+import io.netty.handler.ssl.ApplicationProtocolConfig;
+import io.netty.handler.ssl.ApplicationProtocolNames;
 import io.netty.handler.ssl.OpenSsl;
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.SslContextBuilder;
+import io.netty.handler.ssl.SslHandler;
+import org.xbib.net.URL;
 import org.xbib.netty.http.client.handler.http1.HttpChannelInitializer;
 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.BoundedChannelPool;
-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.SNIHostName;
+import javax.net.ssl.SNIServerName;
+import javax.net.ssl.SSLEngine;
+import javax.net.ssl.SSLException;
+import javax.net.ssl.SSLParameters;
 import javax.net.ssl.TrustManagerFactory;
 import java.io.IOException;
 import java.security.KeyStoreException;
+import java.util.ArrayList;
+import java.util.Collections;
 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.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -45,7 +61,22 @@ public final class Client {
     private static final ThreadFactory httpClientThreadFactory = new HttpClientThreadFactory();
 
     static {
-        NetworkUtils.extendSystemProperties();
+        if (System.getProperty("xbib.netty.http.client.extendsystemproperties") != null) {
+            NetworkUtils.extendSystemProperties();
+        }
+        // change Netty defaults to safer ones, but still allow override from arg line
+        if (System.getProperty("io.netty.noUnsafe") == null) {
+            System.setProperty("io.netty.noUnsafe", Boolean.toString(true));
+        }
+        if (System.getProperty("io.netty.noKeySetOptimization") == null) {
+            System.setProperty("io.netty.noKeySetOptimization", Boolean.toString(true));
+        }
+        if (System.getProperty("io.netty.recycler.maxCapacity") == null) {
+            System.setProperty("io.netty.recycler.maxCapacity", Integer.toString(0));
+        }
+        if (System.getProperty("io.netty.leakDetection.level") == null) {
+            System.setProperty("io.netty.leakDetection.level", "advanced");
+        }
     }
 
     private final ClientConfig clientConfig;
@@ -68,7 +99,7 @@ public final class Client {
 
     private TransportListener transportListener;
 
-    private Pool<Channel> pool;
+    private BoundedChannelPool<HttpAddress> pool;
 
     public Client() {
         this(new ClientConfig());
@@ -84,40 +115,50 @@ public final class Client {
         this.clientConfig = clientConfig;
         initializeTrustManagerFactory(clientConfig);
         this.byteBufAllocator = byteBufAllocator != null ?
-                byteBufAllocator : PooledByteBufAllocator.DEFAULT;
+                byteBufAllocator : ByteBufAllocator.DEFAULT;
-        this.eventLoopGroup = eventLoopGroup != null ?
+        this.eventLoopGroup = eventLoopGroup != null ? eventLoopGroup : clientConfig.isEpoll() ?
-                eventLoopGroup : new NioEventLoopGroup(clientConfig.getThreadCount(), httpClientThreadFactory);
+                    new EpollEventLoopGroup(clientConfig.getThreadCount(), httpClientThreadFactory) :
-        this.socketChannelClass = socketChannelClass != null ?
+                    new NioEventLoopGroup(clientConfig.getThreadCount(), httpClientThreadFactory);
-                socketChannelClass : NioSocketChannel.class;
+        this.socketChannelClass = socketChannelClass != null ? socketChannelClass : clientConfig.isEpoll() ?
+                EpollSocketChannel.class : NioSocketChannel.class;
         this.bootstrap = new Bootstrap()
                 .group(this.eventLoopGroup)
                 .channel(this.socketChannelClass)
+                //.option(ChannelOption.ALLOCATOR, byteBufAllocator)
                 .option(ChannelOption.TCP_NODELAY, clientConfig.isTcpNodelay())
                 .option(ChannelOption.SO_KEEPALIVE, clientConfig.isKeepAlive())
                 .option(ChannelOption.SO_REUSEADDR, clientConfig.isReuseAddr())
                 .option(ChannelOption.SO_SNDBUF, clientConfig.getTcpSendBufferSize())
                 .option(ChannelOption.SO_RCVBUF, clientConfig.getTcpReceiveBufferSize())
                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, clientConfig.getConnectTimeoutMillis())
-                .option(ChannelOption.ALLOCATOR, byteBufAllocator);
+                .option(ChannelOption.WRITE_BUFFER_WATER_MARK, clientConfig.getWriteBufferWaterMark());
         this.httpResponseHandler = new HttpResponseHandler();
         this.http2SettingsHandler = new Http2SettingsHandler();
         this.http2ResponseHandler = new Http2ResponseHandler();
         this.transports = new CopyOnWriteArrayList<>();
-        List<HttpAddress> nodes = clientConfig.getNodes();
+        if (hasPooledConnections()) {
-        if (nodes != null && !nodes.isEmpty()) {
+            List<HttpAddress> nodes = clientConfig.getPoolNodes();
-            Integer limit = clientConfig.getNodeConnectionLimit();
+            Integer limit = clientConfig.getPoolNodeConnectionLimit();
-            if (limit == null || limit > nodes.size()) {
+            if (limit == null || limit < 1) {
-                limit = nodes.size();
-            }
-            if (limit < 1) {
                 limit = 1;
             }
             Semaphore semaphore = new Semaphore(limit);
-            Integer retries = clientConfig.getRetriesPerNode();
+            Integer retries = clientConfig.getRetriesPerPoolNode();
             if (retries == null || retries < 0) {
                 retries = 0;
             }
-            this.pool = new SimpleChannelPool<>(semaphore, nodes, bootstrap, null, retries);
+            ClientChannelPoolHandler clientChannelPoolHandler = new ClientChannelPoolHandler();
+            this.pool = new BoundedChannelPool<>(semaphore, clientConfig.getPoolVersion(),
+                    clientConfig.isPoolSecure(), nodes, bootstrap, clientChannelPoolHandler, retries);
+            Integer nodeConnectionLimit = clientConfig.getPoolNodeConnectionLimit();
+            if (nodeConnectionLimit == null || nodeConnectionLimit == 0) {
+                nodeConnectionLimit = nodes.size();
+            }
+            try {
+                this.pool.prepare(nodeConnectionLimit);
+            } catch (Exception e) {
+                logger.log(Level.SEVERE, e.getMessage(), e);
+            }
         }
     }
 
@@ -133,52 +174,115 @@ public final class Client {
         return byteBufAllocator;
     }
 
+    public EventLoopGroup getEventLoopGroup() {
+        return eventLoopGroup;
+    }
+
     public void setTransportListener(TransportListener transportListener) {
         this.transportListener = transportListener;
     }
 
+    public boolean hasPooledConnections() {
+        return !clientConfig.getPoolNodes().isEmpty();
+    }
+
+    public BoundedChannelPool<HttpAddress> getPool() {
+        return pool;
+    }
+
     public void logDiagnostics(Level level) {
         logger.log(level, () -> "OpenSSL available: " + OpenSsl.isAvailable() +
                 " OpenSSL ALPN support: " + OpenSsl.isAlpnSupported() +
-                " Local host name: " + NetworkUtils.getLocalHostName("localhost"));
+                " Local host name: " + NetworkUtils.getLocalHostName("localhost") +
+                " event loop group: " + eventLoopGroup +
+                " socket: " + socketChannelClass.getName() +
+                " allocator: " + byteBufAllocator.getClass().getName());
         logger.log(level, NetworkUtils::displayNetworkInterfaces);
     }
 
-    public int getTimeout() {
+    public Transport newTransport() {
-        return clientConfig.getReadTimeoutMillis();
+        return newTransport(null);
+    }
+
+    public Transport newTransport(URL url, HttpVersion httpVersion) {
+        return newTransport(HttpAddress.of(url, httpVersion));
     }
 
     public Transport newTransport(HttpAddress httpAddress) {
-        Transport transport;
+        Transport transport = null;
-        if (httpAddress.getVersion().majorVersion() < 2) {
+        if (httpAddress != null) {
-            transport = new HttpTransport(this, httpAddress);
+            if (httpAddress.getVersion().majorVersion() == 1) {
-        } else {
+                transport = new HttpTransport(this, httpAddress);
-            transport = new Http2Transport(this, httpAddress);
+            } else {
+                transport = new Http2Transport(this, httpAddress);
+            }
+        } else if (hasPooledConnections()) {
+            if (pool.getVersion().majorVersion() == 1) {
+                transport = new HttpTransport(this, null);
+            } else {
+                transport = new Http2Transport(this, null);
+            }
         }
-        if (transportListener != null) {
+        if (transport != null) {
-            transportListener.onOpen(transport);
+            if (transportListener != null) {
+                transportListener.onOpen(transport);
+            }
+            transports.add(transport);
         }
-        transports.add(transport);
         return transport;
     }
 
-    public Channel newChannel(HttpAddress httpAddress) throws InterruptedException {
+    public Channel newChannel(HttpAddress httpAddress) throws IOException {
-        HttpVersion httpVersion = httpAddress.getVersion();
+        Channel channel = null;
-        ChannelInitializer<SocketChannel> initializer;
+        if (httpAddress != null) {
-        Channel channel;
+            HttpVersion httpVersion = httpAddress.getVersion();
-        if (httpVersion.majorVersion() < 2) {
+            ChannelInitializer<SocketChannel> initializer;
-            initializer = new HttpChannelInitializer(clientConfig, httpAddress, httpResponseHandler);
+            SslHandler sslHandler = newSslHandler(clientConfig, byteBufAllocator, httpAddress);
-            channel = bootstrap.handler(initializer)
+            if (httpVersion.majorVersion() == 1) {
-                    .connect(httpAddress.getInetSocketAddress()).sync().await().channel();
+                initializer = new HttpChannelInitializer(clientConfig, httpAddress,
+                        sslHandler, httpResponseHandler);
+            } else {
+                initializer = new Http2ChannelInitializer(clientConfig, httpAddress,
+                        sslHandler, http2SettingsHandler, http2ResponseHandler);
+            }
+            try {
+                channel = bootstrap.handler(initializer)
+                        .connect(httpAddress.getInetSocketAddress()).sync().await().channel();
+            } catch (InterruptedException e) {
+                throw new IOException(e);
+            }
         } else {
-            initializer = new Http2ChannelInitializer(clientConfig, httpAddress,
+            if (hasPooledConnections()) {
-                    http2SettingsHandler, http2ResponseHandler);
+                try {
-            channel = bootstrap.handler(initializer)
+                    channel = pool.acquire();
-                    .connect(httpAddress.getInetSocketAddress()).sync().await().channel();
+                } catch (Exception e) {
+                    throw new IOException(e);
+                }
+            } else {
+                throw new UnsupportedOperationException();
+            }
         }
         return channel;
     }
 
+    public Channel newChannel() throws IOException {
+        return newChannel(null);
+    }
+
+    public void releaseChannel(Channel channel) throws IOException{
+        if (hasPooledConnections()) {
+            try {
+                pool.release(channel);
+            } catch (Exception e) {
+                throw new IOException(e);
+            }
+        } else {
+            if (channel != null) {
+                channel.close();
+            }
+        }
+    }
+
     public Transport execute(Request request) throws IOException {
         Transport transport = newTransport(HttpAddress.of(request));
         transport.execute(request);
@@ -190,8 +294,14 @@ public final class Client {
         return newTransport(HttpAddress.of(request)).execute(request, supplier);
     }
 
+    public Transport pooledExecute(Request request) throws IOException {
+        Transport transport = newTransport();
+        transport.execute(request);
+        return transport;
+    }
+
     /**
-     * For following redirects by a chain of transports.
+     * For following redirects, construct a new transport.
      * @param transport the previous transport
      * @param request the new request for continuing the request.
      */
@@ -203,6 +313,13 @@ public final class Client {
         close(nextTransport);
     }
 
+    /**
+     * Retry request by following a back-off strategy.
+     *
+     * @param transport the transport to retry
+     * @param request the request to retry
+     * @throws IOException if retry failed
+     */
     public void retry(Transport transport, Request request) throws IOException {
         transport.execute(request);
         transport.get();
@@ -213,7 +330,7 @@ public final class Client {
         return newTransport(HttpAddress.of(request));
     }
 
-    public void close(Transport transport) {
+    public void close(Transport transport) throws IOException {
         if (transportListener != null) {
             transportListener.onClose(transport);
         }
@@ -221,21 +338,29 @@ public final class Client {
         transports.remove(transport);
     }
 
-    public void close() {
+    public void close() throws IOException {
         for (Transport transport : transports) {
             close(transport);
         }
     }
 
-    public void shutdown() {
+    public void shutdownGracefully() throws IOException {
-        eventLoopGroup.shutdownGracefully();
+        if (hasPooledConnections()) {
-    }
+            pool.close();
-
+        }
-    public void shutdownGracefully() {
         close();
         shutdown();
     }
 
+    public void shutdown() {
+        eventLoopGroup.shutdownGracefully();
+        try {
+            eventLoopGroup.awaitTermination(10L, TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
+            // ignore
+        }
+    }
+
     /**
      * Initialize trust manager factory once per client lifecycle.
      * @param clientConfig the client config
@@ -251,6 +376,60 @@ public final class Client {
         }
     }
 
+    private static SslHandler newSslHandler(ClientConfig clientConfig, ByteBufAllocator allocator, HttpAddress httpAddress) {
+        try {
+            SslContext sslContext = newSslContext(clientConfig);
+            SslHandler sslHandler = sslContext.newHandler(allocator);
+            SSLEngine engine = sslHandler.engine();
+            List<String> serverNames = clientConfig.getServerNamesForIdentification();
+            if (serverNames.isEmpty()) {
+                serverNames = Collections.singletonList(httpAddress.getInetSocketAddress().getHostName());
+            }
+            SSLParameters params = engine.getSSLParameters();
+            params.setEndpointIdentificationAlgorithm("HTTPS");
+            List<SNIServerName> sniServerNames = new ArrayList<>();
+            for (String serverName : serverNames) {
+                sniServerNames.add(new SNIHostName(serverName));
+            }
+            params.setServerNames(sniServerNames);
+            engine.setSSLParameters(params);
+            switch (clientConfig.getClientAuthMode()) {
+                case NEED:
+                    engine.setNeedClientAuth(true);
+                    break;
+                case WANT:
+                    engine.setWantClientAuth(true);
+                    break;
+                default:
+                    break;
+            }
+            return sslHandler;
+        } catch (SSLException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+    private static SslContext newSslContext(ClientConfig clientConfig) throws SSLException {
+        SslContextBuilder sslContextBuilder = SslContextBuilder.forClient()
+                .sslProvider(clientConfig.getSslProvider())
+                .ciphers(Http2SecurityUtil.CIPHERS, clientConfig.getCipherSuiteFilter())
+                .applicationProtocolConfig(newApplicationProtocolConfig());
+        if (clientConfig.getSslContextProvider() != null) {
+            sslContextBuilder.sslContextProvider(clientConfig.getSslContextProvider());
+        }
+        if (clientConfig.getTrustManagerFactory() != null) {
+            sslContextBuilder.trustManager(clientConfig.getTrustManagerFactory());
+        }
+        return sslContextBuilder.build();
+    }
+
+    private static ApplicationProtocolConfig newApplicationProtocolConfig() {
+        return new ApplicationProtocolConfig(ApplicationProtocolConfig.Protocol.ALPN,
+                ApplicationProtocolConfig.SelectorFailureBehavior.NO_ADVERTISE,
+                ApplicationProtocolConfig.SelectedListenerFailureBehavior.ACCEPT,
+                ApplicationProtocolNames.HTTP_2);
+    }
+
     public interface TransportListener {
 
         void onOpen(Transport transport);
@@ -269,4 +448,35 @@ public final class Client {
             return thread;
         }
     }
+
+    class ClientChannelPoolHandler implements ChannelPoolHandler {
+
+        @Override
+        public void channelReleased(Channel channel) {
+        }
+
+        @Override
+        public void channelAcquired(Channel channel) {
+        }
+
+        @Override
+        public void channelCreated(Channel channel) {
+            HttpAddress httpAddress = channel.attr(pool.getAttributeKey()).get();
+            HttpVersion httpVersion = httpAddress.getVersion();
+            SslHandler sslHandler = newSslHandler(clientConfig, byteBufAllocator, httpAddress);
+            if (httpVersion.majorVersion() == 1) {
+                HttpChannelInitializer initializer = new HttpChannelInitializer(clientConfig, httpAddress,
+                        sslHandler, httpResponseHandler);
+                if (channel instanceof SocketChannel) {
+                    initializer.initChannel((SocketChannel) channel);
+                }
+            } else {
+                Http2ChannelInitializer initializer = new Http2ChannelInitializer(clientConfig, httpAddress,
+                        sslHandler, http2SettingsHandler, http2ResponseHandler);
+                if (channel instanceof SocketChannel) {
+                    initializer.initChannel((SocketChannel) channel);
+                }
+            }
+        }
+    }
 }

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

@@ -2,10 +2,14 @@ package org.xbib.netty.http.client;
 
 import io.netty.buffer.ByteBufAllocator;
 import io.netty.channel.EventLoopGroup;
+import io.netty.channel.WriteBufferWaterMark;
 import io.netty.channel.socket.SocketChannel;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.Http2Settings;
 import io.netty.handler.proxy.HttpProxyHandler;
 import io.netty.handler.ssl.CipherSuiteFilter;
 import io.netty.handler.ssl.SslProvider;
+import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 
 import javax.net.ssl.TrustManagerFactory;
 import java.io.InputStream;
@@ -155,11 +159,6 @@ public class ClientBuilder {
         return this;
     }
 
-    public ClientBuilder setTrustManagerFactory(TrustManagerFactory trustManagerFactory) {
-        clientConfig.setTrustManagerFactory(trustManagerFactory);
-        return this;
-    }
-
     public ClientBuilder setKeyCert(InputStream keyCertChainInputStream, InputStream keyInputStream) {
         clientConfig.setKeyCert(keyCertChainInputStream, keyInputStream);
         return this;
@@ -171,8 +170,13 @@ public class ClientBuilder {
         return this;
     }
 
-    public ClientBuilder setServerNameIdentification(boolean serverNameIdentification) {
+    public ClientBuilder setTrustManagerFactory(TrustManagerFactory trustManagerFactory) {
-        clientConfig.setServerNameIdentification(serverNameIdentification);
+        clientConfig.setTrustManagerFactory(trustManagerFactory);
+        return this;
+    }
+
+    public ClientBuilder trustInsecure() {
+        clientConfig.setTrustManagerFactory(InsecureTrustManagerFactory.INSTANCE);
         return this;
     }
 
@@ -186,6 +190,46 @@ public class ClientBuilder {
         return this;
     }
 
+    public ClientBuilder addPoolNode(HttpAddress httpAddress) {
+        clientConfig.addPoolNode(httpAddress);
+        return this;
+    }
+
+    public ClientBuilder setPoolNodeConnectionLimit(int nodeConnectionLimit) {
+        clientConfig.setPoolNodeConnectionLimit(nodeConnectionLimit);
+        return this;
+    }
+
+    public ClientBuilder setRetriesPerPoolNode(int retriesPerNode) {
+        clientConfig.setRetriesPerPoolNode(retriesPerNode);
+        return this;
+    }
+
+    public ClientBuilder setPoolVersion(HttpVersion poolVersion) {
+        clientConfig.setPoolVersion(poolVersion);
+        return this;
+    }
+
+    public ClientBuilder setPoolSecure(boolean poolSecure) {
+        clientConfig.setPoolSecure(poolSecure);
+        return this;
+    }
+
+    public ClientBuilder addServerNameForIdentification(String serverName) {
+        clientConfig.addServerNameForIdentification(serverName);
+        return this;
+    }
+
+    public ClientBuilder setHttp2Settings(Http2Settings http2Settings) {
+        clientConfig.setHttp2Settings(http2Settings);
+        return this;
+    }
+
+    public ClientBuilder setWriteBufferWaterMark(WriteBufferWaterMark writeBufferWaterMark) {
+        clientConfig.setWriteBufferWaterMark(writeBufferWaterMark);
+        return this;
+    }
+
     public Client build() {
         return new Client(clientConfig, byteBufAllocator, eventLoopGroup, socketChannelClass);
     }

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

@@ -1,15 +1,22 @@
 package org.xbib.netty.http.client;
 
+import io.netty.channel.WriteBufferWaterMark;
+import io.netty.channel.epoll.Epoll;
+import io.netty.handler.codec.http.HttpVersion;
 import io.netty.handler.codec.http2.Http2SecurityUtil;
+import io.netty.handler.codec.http2.Http2Settings;
+import io.netty.handler.logging.LogLevel;
 import io.netty.handler.proxy.HttpProxyHandler;
 import io.netty.handler.ssl.CipherSuiteFilter;
 import io.netty.handler.ssl.SslProvider;
 import io.netty.handler.ssl.SupportedCipherSuiteFilter;
+import org.xbib.netty.http.client.retry.BackOff;
 
 import javax.net.ssl.TrustManagerFactory;
 import java.io.InputStream;
 import java.security.KeyStore;
 import java.security.Provider;
+import java.util.ArrayList;
 import java.util.List;
 
 public class ClientConfig {
@@ -22,7 +29,18 @@ public class ClientConfig {
         boolean DEBUG = false;
 
         /**
-         * Default for thread count.
+         * Default debug log level.
+         */
+        LogLevel DEFAULT_DEBUG_LOG_LEVEL = LogLevel.DEBUG;
+
+        /**
+         * The default for selecting epoll. If available, select epoll.
+         */
+        boolean EPOLL = Epoll.isAvailable();
+
+        /**
+         * If set to 0, then Netty will decide about thread count.
+         * Default is Runtime.getRuntime().availableProcessors() * 2
          */
         int THREAD_COUNT = 0;
 
@@ -110,12 +128,40 @@ public class ClientConfig {
          */
         CipherSuiteFilter CIPHER_SUITE_FILTER = SupportedCipherSuiteFilter.INSTANCE;
 
-        boolean USE_SERVER_NAME_IDENTIFICATION = true;
-
         /**
          * Default for SSL client authentication.
          */
         ClientAuthMode SSL_CLIENT_AUTH_MODE = ClientAuthMode.NONE;
+
+        /**
+         * Default for pool retries per node.
+         */
+        Integer RETRIES_PER_NODE = 0;
+
+        /**
+         * Default pool HTTP version.
+         */
+        HttpVersion POOL_VERSION = HttpVersion.HTTP_1_1;
+
+        /**
+         * Default connection pool security.
+         */
+        Boolean POOL_SECURE = false;
+
+        /**
+         * Default HTTP/2 settings.
+         */
+        Http2Settings HTTP2_SETTINGS = Http2Settings.defaultSettings();
+
+        /**
+         * Default write buffer water mark.
+         */
+        WriteBufferWaterMark WRITE_BUFFER_WATER_MARK = WriteBufferWaterMark.DEFAULT;
+
+        /**
+         * Default for backoff.
+         */
+        BackOff BACK_OFF = BackOff.ZERO_BACKOFF;
     }
 
     private static TrustManagerFactory TRUST_MANAGER_FACTORY;
@@ -123,10 +169,6 @@ public class ClientConfig {
     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;
         }
@@ -134,10 +176,10 @@ public class ClientConfig {
 
     private boolean debug = Defaults.DEBUG;
 
-    /**
+    private LogLevel debugLogLevel = Defaults.DEFAULT_DEBUG_LOG_LEVEL;
-     * If set to 0, then Netty will decide about thread count.
+
-     * Default is Runtime.getRuntime().availableProcessors() * 2
+    private boolean epoll = Defaults.EPOLL;
-     */
+
     private int threadCount = Defaults.THREAD_COUNT;
 
     private boolean tcpNodelay = Defaults.TCP_NODELAY;
@@ -178,8 +220,6 @@ public class ClientConfig {
 
     private KeyStore trustManagerKeyStore = null;
 
-    private boolean serverNameIdentification = Defaults.USE_SERVER_NAME_IDENTIFICATION;
-
     private ClientAuthMode clientAuthMode = Defaults.SSL_CLIENT_AUTH_MODE;
 
     private InputStream keyCertChainInputStream;
@@ -190,11 +230,23 @@ public class ClientConfig {
 
     private HttpProxyHandler httpProxyHandler;
 
-    private List<HttpAddress> nodes;
+    private List<HttpAddress> poolNodes = new ArrayList<>();
 
-    private Integer nodeConnectionLimit;
+    private Integer poolNodeConnectionLimit;
 
-    private Integer retriesPerNode;
+    private Integer retriesPerPoolNode = Defaults.RETRIES_PER_NODE;
+
+    private HttpVersion poolVersion = Defaults.POOL_VERSION;
+
+    private Boolean poolSecure = Defaults.POOL_SECURE;
+
+    private List<String> serverNamesForIdentification = new ArrayList<>();
+
+    private Http2Settings http2Settings = Defaults.HTTP2_SETTINGS;
+
+    private WriteBufferWaterMark writeBufferWaterMark = Defaults.WRITE_BUFFER_WATER_MARK;
+
+    private BackOff backOff = Defaults.BACK_OFF;
 
     public ClientConfig setDebug(boolean debug) {
         this.debug = debug;
@@ -215,6 +267,29 @@ public class ClientConfig {
         return debug;
     }
 
+    public ClientConfig setDebugLogLevel(LogLevel debugLogLevel) {
+        this.debugLogLevel = debugLogLevel;
+        return this;
+    }
+
+    public LogLevel getDebugLogLevel() {
+        return debugLogLevel;
+    }
+
+    public ClientConfig enableEpoll() {
+        this.epoll = true;
+        return this;
+    }
+
+    public ClientConfig disableEpoll() {
+        this.epoll = false;
+        return this;
+    }
+
+    public boolean isEpoll() {
+        return epoll;
+    }
+
     public ClientConfig setThreadCount(int threadCount) {
         this.threadCount = threadCount;
         return this;
@@ -341,6 +416,15 @@ public class ClientConfig {
         return enableGzip;
     }
 
+    public ClientConfig setHttp2Settings(Http2Settings http2Settings) {
+        this.http2Settings = http2Settings;
+        return this;
+    }
+
+    public Http2Settings getHttp2Settings() {
+        return http2Settings;
+    }
+
     public ClientConfig setSslProvider(SslProvider sslProvider) {
         this.sslProvider = sslProvider;
         return this;
@@ -413,15 +497,6 @@ public class ClientConfig {
         return keyPassword;
     }
 
-    public ClientConfig setServerNameIdentification(boolean serverNameIdentification) {
-        this.serverNameIdentification = serverNameIdentification;
-        return this;
-    }
-
-    public boolean isServerNameIdentification() {
-        return serverNameIdentification;
-    }
-
     public ClientConfig setClientAuthMode(ClientAuthMode clientAuthMode) {
         this.clientAuthMode = clientAuthMode;
         return this;
@@ -458,31 +533,81 @@ public class ClientConfig {
         return httpProxyHandler;
     }
 
-    public ClientConfig setNodes(List<HttpAddress> nodes) {
+    public ClientConfig setPoolNodes(List<HttpAddress> poolNodes) {
-        this.nodes = nodes;
+        this.poolNodes = poolNodes;
         return this;
     }
 
-    public List<HttpAddress> getNodes() {
+    public List<HttpAddress> getPoolNodes() {
-        return nodes;
+        return poolNodes;
     }
 
-    public ClientConfig setNodeConnectionLimit(Integer nodeConnectionLimit) {
+    public ClientConfig addPoolNode(HttpAddress poolNodeAddress) {
-        this.nodeConnectionLimit = nodeConnectionLimit;
+        this.poolNodes.add(poolNodeAddress);
         return this;
     }
 
-    public Integer getNodeConnectionLimit() {
+    public ClientConfig setPoolNodeConnectionLimit(Integer poolNodeConnectionLimit) {
-        return nodeConnectionLimit;
+        this.poolNodeConnectionLimit = poolNodeConnectionLimit;
-    }
-
-    public ClientConfig setRetriesPerNode(Integer retriesPerNode) {
-        this.retriesPerNode = retriesPerNode;
         return this;
     }
 
-    public Integer getRetriesPerNode() {
+    public Integer getPoolNodeConnectionLimit() {
-        return retriesPerNode;
+        return poolNodeConnectionLimit;
+    }
+
+    public ClientConfig setRetriesPerPoolNode(Integer retriesPerPoolNode) {
+        this.retriesPerPoolNode = retriesPerPoolNode;
+        return this;
+    }
+
+    public Integer getRetriesPerPoolNode() {
+        return retriesPerPoolNode;
+    }
+
+    public ClientConfig setPoolVersion(HttpVersion poolVersion) {
+        this.poolVersion = poolVersion;
+        return this;
+    }
+
+    public HttpVersion getPoolVersion() {
+        return  poolVersion;
+    }
+
+    public ClientConfig setPoolSecure(boolean poolSecure) {
+        this.poolSecure = poolSecure;
+        return this;
+    }
+
+    public boolean isPoolSecure() {
+        return poolSecure;
+    }
+
+    public ClientConfig addServerNameForIdentification(String serverNameForIdentification) {
+        this.serverNamesForIdentification.add(serverNameForIdentification);
+        return this;
+    }
+
+    public List<String> getServerNamesForIdentification() {
+        return serverNamesForIdentification;
+    }
+
+    public ClientConfig setWriteBufferWaterMark(WriteBufferWaterMark writeBufferWaterMark) {
+        this.writeBufferWaterMark = writeBufferWaterMark;
+        return this;
+    }
+
+    public WriteBufferWaterMark getWriteBufferWaterMark() {
+        return writeBufferWaterMark;
+    }
+
+    public ClientConfig setBackOff(BackOff backOff) {
+        this.backOff = backOff;
+        return this;
+    }
+
+    public BackOff getBackOff() {
+        return backOff;
     }
 
     @Override
@@ -491,7 +616,5 @@ public class ClientConfig {
         sb.append("SSL=").append(sslProvider)
                 .append(",SSL context provider=").append(sslContextProvider != null ? sslContextProvider.getName() : "<none>");
         return sb.toString();
-
-
     }
 }

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

@@ -10,14 +10,18 @@ import org.xbib.net.URL;
 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 org.xbib.netty.http.client.retry.BackOff;
 
+import java.io.Closeable;
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
+import java.util.concurrent.CompletableFuture;
 
 /**
- *
+ * HTTP client request.
  */
-public class Request {
+public class Request implements Closeable {
 
     private final URL base;
 
@@ -33,7 +37,7 @@ public class Request {
 
     private final ByteBuf content;
 
-    private final int timeout;
+    private final long timeoutInMillis;
 
     private final boolean followRedirect;
 
@@ -41,6 +45,12 @@ public class Request {
 
     private int redirectCount;
 
+    private final boolean isBackOff;
+
+    private final BackOff backOff;
+
+    private CompletableFuture<?> completableFuture;
+
     private HttpResponseListener responseListener;
 
     private HttpHeadersListener headersListener;
@@ -50,7 +60,8 @@ public class Request {
     Request(URL url, HttpVersion httpVersion, HttpMethod httpMethod,
             HttpHeaders headers, Collection<Cookie> cookies,
             String uri, ByteBuf content,
-            int timeout, boolean followRedirect, int maxRedirect, int redirectCount) {
+            long timeoutInMillis, boolean followRedirect, int maxRedirect, int redirectCount,
+            boolean isBackOff, BackOff backOff) {
         this.base = url;
         this.httpVersion = httpVersion;
         this.httpMethod = httpMethod;
@@ -58,10 +69,12 @@ public class Request {
         this.cookies = cookies;
         this.uri = uri;
         this.content = content;
-        this.timeout = timeout;
+        this.timeoutInMillis = timeoutInMillis;
         this.followRedirect = followRedirect;
         this.maxRedirects = maxRedirect;
         this.redirectCount = redirectCount;
+        this.isBackOff = isBackOff;
+        this.backOff = backOff;
     }
 
     public URL base() {
@@ -92,15 +105,27 @@ public class Request {
         return content;
     }
 
-    public int getTimeout() {
+    /**
-        return timeout;
+     * Return the timeout in milliseconds per request. This overrides the read timeout of the client.
+     * @return timeout timeout in milliseconds
+     */
+    public long getTimeoutInMillis() {
+        return timeoutInMillis;
     }
 
     public boolean isFollowRedirect() {
         return followRedirect;
     }
 
-    public boolean checkRedirect() {
+    public boolean isBackOff() {
+        return isBackOff;
+    }
+
+    public BackOff getBackOff() {
+        return backOff;
+    }
+
+    public boolean canRedirect() {
         if (!followRedirect) {
             return false;
         }
@@ -124,6 +149,15 @@ public class Request {
         return sb.toString();
     }
 
+    public Request setCompletableFuture(CompletableFuture<?> completableFuture) {
+        this.completableFuture = completableFuture;
+        return this;
+    }
+
+    public CompletableFuture<?> getCompletableFuture() {
+        return completableFuture;
+    }
+
     public Request setHeadersListener(HttpHeadersListener httpHeadersListener) {
         this.headersListener = httpHeadersListener;
         return this;
@@ -190,4 +224,11 @@ public class Request {
     public static RequestBuilder builder(HttpMethod httpMethod) {
         return new RequestBuilder().setMethod(httpMethod);
     }
+
+    @Override
+    public void close() throws IOException {
+        if (content != null) {
+            content.release();
+        }
+    }
 }

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

@@ -16,6 +16,7 @@ import io.netty.util.AsciiString;
 import org.xbib.net.QueryParameters;
 import org.xbib.net.URL;
 import org.xbib.net.URLSyntaxException;
+import org.xbib.netty.http.client.retry.BackOff;
 
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
@@ -44,7 +45,7 @@ public class RequestBuilder {
 
     private static final boolean DEFAULT_FOLLOW_REDIRECT = true;
 
-    private static final int DEFAULT_TIMEOUT_MILLIS = 5000;
+    private static final long DEFAULT_TIMEOUT_MILLIS = -1L;
 
     private static final int DEFAULT_MAX_REDIRECT = 10;
 
@@ -74,12 +75,16 @@ public class RequestBuilder {
 
     private ByteBuf content;
 
-    private int timeout;
+    private long timeoutInMillis;
 
     private boolean followRedirect;
 
     private int maxRedirects;
 
+    private boolean enableBackOff;
+
+    private BackOff backOff;
+
     RequestBuilder() {
         httpMethod = DEFAULT_METHOD;
         httpVersion = DEFAULT_HTTP_VERSION;
@@ -87,7 +92,7 @@ public class RequestBuilder {
         gzip = DEFAULT_GZIP;
         keepalive = DEFAULT_KEEPALIVE;
         url = DEFAULT_URL;
-        timeout = DEFAULT_TIMEOUT_MILLIS;
+        timeoutInMillis = DEFAULT_TIMEOUT_MILLIS;
         followRedirect = DEFAULT_FOLLOW_REDIRECT;
         maxRedirects = DEFAULT_MAX_REDIRECT;
         headers = new DefaultHttpHeaders();
@@ -121,8 +126,8 @@ public class RequestBuilder {
         return this;
     }
 
-    public RequestBuilder setTimeout(int timeout) {
+    public RequestBuilder setTimeoutInMillis(long timeoutInMillis) {
-        this.timeout = timeout;
+        this.timeoutInMillis = timeoutInMillis;
         return this;
     }
 
@@ -207,6 +212,16 @@ public class RequestBuilder {
         return this;
     }
 
+    public RequestBuilder enableBackOff(boolean enableBackOff) {
+        this.enableBackOff = enableBackOff;
+        return this;
+    }
+
+    public RequestBuilder setBackOff(BackOff backOff) {
+        this.backOff = backOff;
+        return this;
+    }
+
     public RequestBuilder setUserAgent(String userAgent) {
         this.userAgent = userAgent;
         return this;
@@ -255,14 +270,10 @@ public class RequestBuilder {
             throw new IllegalStateException("host in URL not defined: " + url);
         }
         if (uri != null) {
-            if (this.url != null) {
+            try {
-                try {
+                url = URL.base(url).resolve(uri);
-                    url = URL.base(url).resolve(uri);
+            } catch (URLSyntaxException e) {
-                } catch (URLSyntaxException e) {
+                throw new IllegalArgumentException(e);
-                    throw new IllegalArgumentException(e);
-                }
-            } else {
-                url(uri);
             }
         }
         // add explicit parameters to URL
@@ -320,7 +331,7 @@ public class RequestBuilder {
             validatedHeaders.remove(headerName);
         }
         return new Request(url, httpVersion, httpMethod, validatedHeaders, cookies, uri, content,
-                timeout, followRedirect, maxRedirects, 0);
+                timeoutInMillis, followRedirect, maxRedirects, 0, enableBackOff, backOff);
     }
 
     private void addHeader(AsciiString name, Object value) {

src/main/java/org/xbib/netty/http/client/handler/UserEventLogger.java

@@ -1,30 +0,0 @@
-package org.xbib.netty.http.client.handler;
-
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
-import io.netty.channel.socket.ChannelInputShutdownReadComplete;
-import io.netty.handler.ssl.SslCloseCompletionEvent;
-
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-/**
- * A Netty handler that logs user events and find expetced ones.
- */
-@ChannelHandler.Sharable
-class UserEventLogger extends ChannelInboundHandlerAdapter {
-
-    private static final Logger logger = Logger.getLogger(UserEventLogger.class.getName());
-
-    @Override
-    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
-        logger.log(Level.FINE, () -> "got user event " + evt);
-        if (evt instanceof SslCloseCompletionEvent ||
-                evt instanceof ChannelInputShutdownReadComplete) {
-            logger.log(Level.FINE, () -> "user event is expected: " + evt);
-            return;
-        }
-        super.userEventTriggered(ctx, evt);
-    }
-}

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

@@ -6,87 +6,59 @@ import io.netty.channel.socket.SocketChannel;
 import io.netty.handler.codec.http.HttpClientCodec;
 import io.netty.handler.codec.http.HttpContentDecompressor;
 import io.netty.handler.codec.http.HttpObjectAggregator;
-import io.netty.handler.ssl.SslContext;
+import io.netty.handler.logging.LogLevel;
-import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.SslHandler;
 import org.xbib.netty.http.client.ClientConfig;
 import org.xbib.netty.http.client.HttpAddress;
-import org.xbib.netty.http.client.handler.TrafficLoggingHandler;
 
-import javax.net.ssl.SNIHostName;
+import java.util.logging.Level;
-import javax.net.ssl.SSLEngine;
+import java.util.logging.Logger;
-import javax.net.ssl.SSLException;
-import javax.net.ssl.SSLParameters;
-import java.util.Collections;
 
 public class HttpChannelInitializer extends ChannelInitializer<SocketChannel> {
 
+    private static final Logger logger = Logger.getLogger(HttpChannelInitializer.class.getName());
+
     private final ClientConfig clientConfig;
 
     private final HttpAddress httpAddress;
 
+    private final SslHandler sslHandler;
+
     private final HttpResponseHandler httpResponseHandler;
 
-    public HttpChannelInitializer(ClientConfig clientConfig, HttpAddress httpAddress, HttpResponseHandler httpResponseHandler) {
+    public HttpChannelInitializer(ClientConfig clientConfig,
+                                  HttpAddress httpAddress,
+                                  SslHandler sslHandler,
+                                  HttpResponseHandler httpResponseHandler) {
         this.clientConfig = clientConfig;
         this.httpAddress = httpAddress;
+        this.sslHandler = sslHandler;
         this.httpResponseHandler = httpResponseHandler;
     }
 
     @Override
-    protected void initChannel(SocketChannel ch) {
+    public void initChannel(SocketChannel channel) {
         if (clientConfig.isDebug()) {
-            ch.pipeline().addLast(new TrafficLoggingHandler());
+            channel.pipeline().addLast(new TrafficLoggingHandler(LogLevel.DEBUG));
         }
         if (httpAddress.isSecure()) {
-            configureEncryptedHttp1(ch);
+            configureEncrypted(channel);
         } else {
-            configureCleartextHttp1(ch);
+            configureCleartext(channel);
+        }
+        if (clientConfig.isDebug()) {
+            logger.log(Level.FINE, "HTTP 1 channel initialized: " + channel.pipeline().names());
         }
     }
 
-    private void configureEncryptedHttp1(SocketChannel ch)  {
+    private void configureEncrypted(SocketChannel channel)  {
-        ChannelPipeline pipeline = ch.pipeline();
+        ChannelPipeline pipeline = channel.pipeline();
-        try {
+        pipeline.addLast(sslHandler);
-            SslContextBuilder sslContextBuilder = SslContextBuilder.forClient()
+        configureCleartext(channel);
-                    .sslProvider(clientConfig.getSslProvider())
-                    .keyManager(clientConfig.getKeyCertChainInputStream(), clientConfig.getKeyInputStream(),
-                            clientConfig.getKeyPassword())
-                    .ciphers(clientConfig.getCiphers(), clientConfig.getCipherSuiteFilter());
-            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();
-            if (clientConfig.isServerNameIdentification()) {
-                String fullQualifiedHostname = httpAddress.getInetSocketAddress().getHostName();
-                SSLParameters params = engine.getSSLParameters();
-                params.setServerNames(Collections.singletonList(new SNIHostName(fullQualifiedHostname)));
-                engine.setSSLParameters(params);
-            }
-            pipeline.addLast(sslHandler);
-            switch (clientConfig.getClientAuthMode()) {
-                case NEED:
-                    engine.setNeedClientAuth(true);
-                    break;
-                case WANT:
-                    engine.setWantClientAuth(true);
-                    break;
-                default:
-                    break;
-            }
-        } catch (SSLException e) {
-            throw new IllegalStateException("unable to configure SSL: " + e.getMessage(), e);
-        }
-        configureCleartextHttp1(ch);
     }
 
-    private void configureCleartextHttp1(SocketChannel ch) {
+    private void configureCleartext(SocketChannel channel) {
-        ChannelPipeline pipeline = ch.pipeline();
+        ChannelPipeline pipeline = channel.pipeline();
         pipeline.addLast(new HttpClientCodec(clientConfig.getMaxInitialLineLength(),
                  clientConfig.getMaxHeadersSize(), clientConfig.getMaxChunkSize()));
         if (clientConfig.isEnableGzip()) {

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

@@ -1,4 +1,4 @@
-package org.xbib.netty.http.client.handler;
+package org.xbib.netty.http.client.handler.http1;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandler;
@@ -13,8 +13,8 @@ import io.netty.handler.logging.LoggingHandler;
 @ChannelHandler.Sharable
 public class TrafficLoggingHandler extends LoggingHandler {
 
-    public TrafficLoggingHandler() {
+    public TrafficLoggingHandler(LogLevel level) {
-        super("client", LogLevel.TRACE);
+        super("client", level);
     }
 
     @Override

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

@@ -7,25 +7,14 @@ import io.netty.handler.codec.http2.DefaultHttp2Connection;
 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;
 import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandlerBuilder;
 import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapterBuilder;
-import io.netty.handler.logging.LogLevel;
-import io.netty.handler.ssl.ApplicationProtocolConfig;
 import io.netty.handler.ssl.ApplicationProtocolNames;
 import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
-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 org.xbib.netty.http.client.ClientConfig;
 import org.xbib.netty.http.client.HttpAddress;
 
-import javax.net.ssl.SNIHostName;
-import javax.net.ssl.SSLEngine;
-import javax.net.ssl.SSLException;
-import javax.net.ssl.SSLParameters;
-import java.util.Collections;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -37,30 +26,69 @@ public class Http2ChannelInitializer extends ChannelInitializer<SocketChannel> {
 
     private final HttpAddress httpAddress;
 
+    private final SslHandler sslHandler;
+
     private final Http2SettingsHandler http2SettingsHandler;
 
     private final Http2ResponseHandler http2ResponseHandler;
 
     public Http2ChannelInitializer(ClientConfig clientConfig,
                             HttpAddress httpAddress,
+                            SslHandler sslHandler,
                             Http2SettingsHandler http2SettingsHandler,
                             Http2ResponseHandler http2ResponseHandler) {
         this.clientConfig = clientConfig;
         this.httpAddress = httpAddress;
+        this.sslHandler = sslHandler;
         this.http2SettingsHandler = http2SettingsHandler;
         this.http2ResponseHandler = http2ResponseHandler;
     }
 
     /**
-     * The channel initialization for HTTP/2 is always encrypted.
+     * The channel initialization for HTTP/2.
-     * The reason is there is no known HTTP/2 server supporting cleartext.
      *
-     * @param ch socket channel
+     * @param channel socket channel
      */
     @Override
-    protected void initChannel(SocketChannel ch) {
+    public void initChannel(SocketChannel channel) {
+        if (httpAddress.isSecure()) {
+            configureEncrypted(channel);
+        } else {
+            configureCleartext(channel);
+        }
+        if (clientConfig.isDebug()) {
+            logger.log(Level.FINE, "HTTP/2 channel initialized: " + channel.pipeline().names());
+        }
+    }
+
+    private void configureEncrypted(SocketChannel channel) {
+        channel.pipeline().addLast(sslHandler);
+        ApplicationProtocolNegotiationHandler negotiationHandler = new ApplicationProtocolNegotiationHandler("") {
+            @Override
+            protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
+                if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
+                    ctx.pipeline().addLast(newConnectionHandler(), http2SettingsHandler, http2ResponseHandler);
+                    if (clientConfig.isDebug()) {
+                        logger.log(Level.FINE, "after negotiation: " + ctx.pipeline().names());
+                    }
+                    return;
+                }
+                // we do not fall back to HTTP1
+                ctx.close();
+                throw new IllegalStateException("protocol not accepted: " + protocol);
+            }
+        };
+        channel.pipeline().addLast(negotiationHandler);
+}
+
+    private void configureCleartext(SocketChannel ch) {
+        ch.pipeline().addLast(newConnectionHandler(), http2SettingsHandler, http2ResponseHandler);
+    }
+
+    private Http2ConnectionHandler newConnectionHandler() {
         Http2Connection http2Connection = new DefaultHttp2Connection(false);
         HttpToHttp2ConnectionHandlerBuilder http2ConnectionHandlerBuilder = new HttpToHttp2ConnectionHandlerBuilder()
+                .initialSettings(clientConfig.getHttp2Settings())
                 .connection(http2Connection)
                 .frameListener(new Http2PushPromiseHandler(http2Connection,
                         new InboundHttp2ToHttpAdapterBuilder(http2Connection)
@@ -68,48 +96,8 @@ public class Http2ChannelInitializer extends ChannelInitializer<SocketChannel> {
                                 .propagateSettings(true)
                                 .build()));
         if (clientConfig.isDebug()) {
-            http2ConnectionHandlerBuilder.frameLogger(new Http2FrameLogger(LogLevel.INFO, "client"));
+            http2ConnectionHandlerBuilder.frameLogger(new Http2FrameLogger(clientConfig.getDebugLogLevel(), "client"));
-        }
-        Http2ConnectionHandler http2ConnectionHandler = http2ConnectionHandlerBuilder.build();
-        try {
-            SslContextBuilder sslContextBuilder = SslContextBuilder.forClient()
-                    .sslProvider(clientConfig.getSslProvider())
-                    .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
-                    .applicationProtocolConfig(new ApplicationProtocolConfig(
-                            ApplicationProtocolConfig.Protocol.ALPN,
-                            ApplicationProtocolConfig.SelectorFailureBehavior.NO_ADVERTISE,
-                            ApplicationProtocolConfig.SelectedListenerFailureBehavior.ACCEPT,
-                            ApplicationProtocolNames.HTTP_2));
-            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();
-            if (clientConfig.isServerNameIdentification()) {
-                String fullQualifiedHostname = httpAddress.getInetSocketAddress().getHostName();
-                SSLParameters params = engine.getSSLParameters();
-                params.setServerNames(Collections.singletonList(new SNIHostName(fullQualifiedHostname)));
-                engine.setSSLParameters(params);
-            }
-            ch.pipeline().addLast(sslHandler);
-            ApplicationProtocolNegotiationHandler negotiationHandler = new ApplicationProtocolNegotiationHandler("") {
-                @Override
-                protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
-                    if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
-                        ctx.pipeline().addLast(http2ConnectionHandler, http2SettingsHandler, http2ResponseHandler);
-                        return;
-                    }
-                    ctx.close();
-                    throw new IllegalStateException("unknown protocol: " + protocol);
-                }
-            };
-            ch.pipeline().addLast(negotiationHandler);
-        } catch (SSLException e) {
-            logger.log(Level.SEVERE, e.getMessage(), e);
         }
+        return http2ConnectionHandlerBuilder.build();
     }
 }

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

@@ -6,14 +6,18 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.pool.ChannelPoolHandler;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.handler.codec.http.HttpVersion;
 import io.netty.util.AttributeKey;
 
 import java.net.ConnectException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Queue;
+import java.util.Set;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.ThreadLocalRandom;
@@ -22,12 +26,16 @@ 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 BoundedChannelPool<K extends PoolKey> implements Pool<Channel> {
 
-    private static final Logger logger = Logger.getLogger(SimpleChannelPool.class.getName());
+    private static final Logger logger = Logger.getLogger(BoundedChannelPool.class.getName());
 
     private final Semaphore semaphore;
 
+    private final HttpVersion httpVersion;
+
+    private final boolean isSecure;
+
     private final ChannelPoolHandler channelPoolhandler;
 
     private final List<K> nodes;
@@ -52,6 +60,8 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
 
     /**
      * @param semaphore the concurrency level
+     * @param httpVersion  the HTTP version of the pool connections
+     * @param isSecure if this pool has secure connections
      * @param nodes the endpoint nodes, any element may contain the port (followed after ":")
      *             to override the defaultPort argument
      * @param bootstrap bootstrap instance
@@ -59,16 +69,19 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
      * @param retriesPerNode the max count of the subsequent connection failures to the node before
      *                       the node will be excluded from the pool. If set to 0, the value is ignored.
      */
-    public SimpleChannelPool(Semaphore semaphore, List<K> nodes, Bootstrap bootstrap,
+    public BoundedChannelPool(Semaphore semaphore, HttpVersion httpVersion, boolean isSecure,
-                             ChannelPoolHandler channelPoolHandler, int retriesPerNode) {
+                              List<K> nodes, Bootstrap bootstrap,
+                              ChannelPoolHandler channelPoolHandler, int retriesPerNode) {
         this.semaphore = semaphore;
+        this.httpVersion = httpVersion;
+        this.isSecure = isSecure;
         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");
+            throw new IllegalArgumentException("nodes must not be empty");
         }
         this.numberOfNodes = nodes.size();
         bootstraps = new HashMap<>(numberOfNodes);
@@ -77,46 +90,48 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
         counts = new HashMap<>(numberOfNodes);
         failedCounts = new HashMap<>(numberOfNodes);
         for (K node : nodes) {
+            ChannelPoolInitializer initializer = new ChannelPoolInitializer(node, channelPoolHandler);
             bootstraps.put(node, bootstrap.clone().remoteAddress(node.getInetSocketAddress())
-                .handler(new ChannelInitializer<Channel>() {
+                .handler(initializer));
-                    @Override
-                    protected void initChannel(Channel channel) throws Exception {
-                        if(!channel.eventLoop().inEventLoop()) {
-                            throw new IllegalStateException();
-                        }
-                        if (channelPoolHandler != null) {
-                            channelPoolHandler.channelCreated(channel);
-                        }
-                    }
-                }));
             availableChannels.put(node, new ConcurrentLinkedQueue<>());
             counts.put(node, 0);
             failedCounts.put(node, 0);
         }
     }
 
+    public HttpVersion getVersion() {
+        return httpVersion;
+    }
+
+    public boolean isSecure() {
+        return isSecure;
+    }
+
+    public AttributeKey<K> getAttributeKey() {
+        return attributeKey;
+    }
+
     @Override
-    public void prepare(int count) throws ConnectException {
+    public void prepare(int channelCount) throws ConnectException {
-        if (count > 0) {
+        if (channelCount <= 0) {
-            for (int i = 0; i < count; i ++) {
+            throw new IllegalArgumentException("channel count must be greater zero, but got " + channelCount);
-                Channel channel = connectToAnyNode();
-                if (channel == null) {
-                    throw new ConnectException("failed to prepare the connections");
-                }
-                K nodeAddr = channel.attr(attributeKey).get();
-                if (channel.isActive()) {
-                    Queue<Channel> channelQueue = availableChannels.get(nodeAddr);
-                    if (channelQueue != null) {
-                        channelQueue.add(channel);
-                    }
-                } else {
-                    channel.close();
-                }
-            }
-            logger.log(Level.FINE,"prepared " + count + " connections");
-        } else {
-            throw new IllegalArgumentException("Connection count should be > 0, but got " + count);
         }
+        for (int i = 0; i < channelCount; i++) {
+            Channel channel = newConnection();
+            if (channel == null) {
+                throw new ConnectException("failed to prepare");
+            }
+            K key = channel.attr(attributeKey).get();
+            if (channel.isActive()) {
+                Queue<Channel> channelQueue = availableChannels.get(key);
+                if (channelQueue != null) {
+                    channelQueue.add(channel);
+                }
+            } else {
+                channel.close();
+            }
+        }
+        logger.log(Level.FINE,"prepared " + channelCount + " channels");
     }
 
     @Override
@@ -124,7 +139,7 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
         Channel channel = null;
         if (semaphore.tryAcquire()) {
             if ((channel = poll()) == null) {
-                channel = connectToAnyNode();
+                channel = newConnection();
             }
             if (channel == null) {
                 semaphore.release();
@@ -150,7 +165,7 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
         Channel channel;
         for (int i = 0; i < availableCount; i ++) {
             if (null == (channel = poll())) {
-                channel = connectToAnyNode();
+                channel = newConnection();
             }
             if (channel == null) {
                 semaphore.release(availableCount - i);
@@ -167,18 +182,23 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
 
     @Override
     public void release(Channel channel) throws Exception {
-        K nodeAddr = channel.attr(attributeKey).get();
+        try {
-        if (channel.isActive()) {
+            if (channel != null) {
-            Queue<Channel> channelQueue = availableChannels.get(nodeAddr);
+                if (channel.isActive()) {
-            if (channelQueue != null) {
+                    K key = channel.attr(attributeKey).get();
-                channelQueue.add(channel);
+                    Queue<Channel> channelQueue = availableChannels.get(key);
+                    if (channelQueue != null) {
+                        channelQueue.add(channel);
+                    }
+                } else if (channel.isOpen()) {
+                    channel.close();
+                }
+                if (channelPoolhandler != null) {
+                    channelPoolhandler.channelReleased(channel);
+                }
             }
+        } finally {
             semaphore.release();
-        } else {
-            channel.close();
-        }
-        if (channelPoolhandler != null) {
-            channelPoolhandler.channelReleased(channel);
         }
     }
 
@@ -193,65 +213,63 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
     public void close() {
         lock.lock();
         try {
-            int closedConnCount = 0;
+            int count = 0;
-            for (K nodeAddr : availableChannels.keySet()) {
+            Set<Channel> channelSet = new HashSet<>();
-                for (Channel conn : availableChannels.get(nodeAddr)) {
+            for (Map.Entry<K, Queue<Channel>> entry : availableChannels.entrySet()) {
-                    if (conn.isOpen()) {
+                channelSet.addAll(entry.getValue());
-                        conn.close();
+            }
-                        closedConnCount++;
+            for (Map.Entry<K, List<Channel>> entry : channels.entrySet()) {
-                    }
+                channelSet.addAll(entry.getValue());
+            }
+            for (Channel channel : channelSet) {
+                if (channel != null && channel.isOpen()) {
+                    logger.log(Level.FINE, "closing channel " + channel);
+                    channel.close();
+                    count++;
                 }
             }
             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");
+            logger.log(Level.FINE, "closed " + count + " connections");
         } finally {
             lock.unlock();
         }
     }
 
-    private Channel connectToAnyNode() throws ConnectException {
+    private Channel newConnection() throws ConnectException {
         Channel channel = null;
-        K nodeAddr = null;
+        K key = null;
-        K nextNodeAddr;
+        K nextKey;
         int min = Integer.MAX_VALUE;
         int next;
         int i = ThreadLocalRandom.current().nextInt(numberOfNodes);
         for (int j = i; j < numberOfNodes; j ++) {
-            nextNodeAddr = nodes.get(j % numberOfNodes);
+            nextKey = nodes.get(j % numberOfNodes);
-            next = counts.get(nextNodeAddr);
+            next = counts.get(nextKey);
-            if(next == 0) {
+            if (next == 0) {
-                nodeAddr = nextNodeAddr;
+                key = nextKey;
                 break;
             } else if (next < min) {
                 min = next;
-                nodeAddr = nextNodeAddr;
+                key = nextKey;
             }
         }
-        if (nodeAddr != null) {
+        if (key != null) {
-            logger.log(Level.FINE, "trying connection to " + nodeAddr);
+            logger.log(Level.FINE, "trying connection to " + key);
             try {
-                channel = connect(nodeAddr);
+                channel = connect(key);
             } catch (Exception e) {
-                logger.log(Level.WARNING, "failed to create a new connection to " + nodeAddr + ": " + e.toString());
+                logger.log(Level.WARNING, "failed to create a new connection to " + key + ": " + e.toString());
                 if (retriesPerNode > 0) {
-                    int selectedNodeFailedConnAttemptsCount = failedCounts.get(nodeAddr) + 1;
+                    int selectedNodeFailedConnAttemptsCount = failedCounts.get(key) + 1;
-                    failedCounts.put(nodeAddr, selectedNodeFailedConnAttemptsCount);
+                    failedCounts.put(key, selectedNodeFailedConnAttemptsCount);
                     if (selectedNodeFailedConnAttemptsCount > retriesPerNode) {
-                        logger.log(Level.WARNING, "failed to connect to the node " + nodeAddr + " "
+                        logger.log(Level.WARNING, "failed to connect to the node " + key + " "
                                         + selectedNodeFailedConnAttemptsCount + " times, "
                                         + "excluding the node from the connection pool");
-                        counts.put(nodeAddr, Integer.MAX_VALUE);
+                        counts.put(key, Integer.MAX_VALUE);
                         boolean allNodesExcluded = true;
                         for (K node : nodes) {
                             if (counts.get(node) < Integer.MAX_VALUE) {
@@ -272,22 +290,22 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
             }
         }
         if (channel != null) {
-            channel.closeFuture().addListener(new CloseChannelListener(nodeAddr, channel));
+            channel.closeFuture().addListener(new CloseChannelListener(key, channel));
-            channel.attr(attributeKey).set(nodeAddr);
+            channel.attr(attributeKey).set(key);
-            channels.computeIfAbsent(nodeAddr, node -> new ArrayList<>()).add(channel);
+            channels.computeIfAbsent(key, node -> new ArrayList<>()).add(channel);
             synchronized (counts) {
-                counts.put(nodeAddr, counts.get(nodeAddr) + 1);
+                counts.put(key, counts.get(key) + 1);
             }
-            if(retriesPerNode > 0) {
+            if (retriesPerNode > 0) {
-                failedCounts.put(nodeAddr, 0);
+                failedCounts.put(key, 0);
             }
-            logger.log(Level.FINE,"new connection to " + nodeAddr + " created");
+            logger.log(Level.FINE,"new connection to " + key + " created");
         }
         return channel;
     }
 
-    private Channel connect(K addr) throws Exception {
+    private Channel connect(K key) throws Exception {
-        Bootstrap bootstrap = bootstraps.get(addr);
+        Bootstrap bootstrap = bootstraps.get(key);
         if (bootstrap != null) {
             return bootstrap.connect().sync().channel();
         }
@@ -312,26 +330,26 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
 
     private class CloseChannelListener implements ChannelFutureListener {
 
-        private final K nodeAddr;
+        private final K key;
         private final Channel channel;
 
-        private CloseChannelListener(K nodeAddr, Channel channel) {
+        private CloseChannelListener(K key, Channel channel) {
-            this.nodeAddr = nodeAddr;
+            this.key = key;
             this.channel = channel;
         }
 
         @Override
         public void operationComplete(ChannelFuture future) {
-            logger.log(Level.FINE,"connection to " + nodeAddr + " closed");
+            logger.log(Level.FINE,"connection to " + key + " closed");
             lock.lock();
             try {
                 synchronized (counts) {
-                    if (counts.containsKey(nodeAddr)) {
+                    if (counts.containsKey(key)) {
-                        counts.put(nodeAddr, counts.get(nodeAddr) - 1);
+                        counts.put(key, counts.get(key) - 1);
                     }
                 }
                 synchronized (channels) {
-                    List<Channel> channels = SimpleChannelPool.this.channels.get(nodeAddr);
+                    List<Channel> channels = BoundedChannelPool.this.channels.get(key);
                     if (channels != null) {
                         channels.remove(channel);
                     }
@@ -342,4 +360,27 @@ public class SimpleChannelPool<K extends PoolKey> implements Pool<Channel> {
             }
         }
     }
+
+    class ChannelPoolInitializer extends ChannelInitializer<SocketChannel> {
+
+        private final K key;
+
+        private final ChannelPoolHandler channelPoolHandler;
+
+        ChannelPoolInitializer(K key, ChannelPoolHandler channelPoolHandler) {
+            this.key = key;
+            this.channelPoolHandler = channelPoolHandler;
+        }
+
+        @Override
+        protected void initChannel(SocketChannel channel) throws Exception {
+            if (!channel.eventLoop().inEventLoop()) {
+                throw new IllegalStateException();
+            }
+            channel.attr(attributeKey).set(key);
+            if (channelPoolHandler != null) {
+                channelPoolHandler.channelCreated(channel);
+            }
+        }
+    }
 }

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

@@ -36,7 +36,13 @@ public class RestClient {
 
     public String asString() {
         ByteBuf byteBuf = response != null ? response.content() : null;
-        return byteBuf != null && byteBuf.isReadable() ? response.content().toString(StandardCharsets.UTF_8) : null;
+        try {
+            return byteBuf != null && byteBuf.isReadable() ? response.content().toString(StandardCharsets.UTF_8) : null;
+        } finally {
+            if (byteBuf != null) {
+                byteBuf.release();
+            }
+        }
     }
 
     public static RestClient get(String urlString) throws IOException {

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

@@ -14,7 +14,7 @@ public interface BackOff {
     /**
      * Reset to initial state.
      */
-    void reset() throws IOException;
+    void reset();
 
     /**
      * Gets the number of milliseconds to wait before retrying the operation or {@link #STOP} to
@@ -33,7 +33,7 @@ public interface BackOff {
      }
      * </pre>
      */
-    long nextBackOffMillis() throws IOException;
+    long nextBackOffMillis();
 
     /**
      * Fixed back-off policy whose back-off time is always zero, meaning that the operation is retried

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

@@ -137,22 +137,19 @@ public class ExponentialBackOff implements BackOff {
     /**
      * @param builder builder
      */
-    protected ExponentialBackOff(Builder builder) {
+    private 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. */
+    /**
+     * Sets the interval back to the initial retry interval and restarts the timer.
+     */
     public final void reset() {
         currentIntervalMillis = initialIntervalMillis;
         startTimeNanos = nanoClock.nanoTime();
@@ -275,6 +272,29 @@ public class ExponentialBackOff implements BackOff {
         }
     }
 
+    /**
+     * 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>
+     *
+     */
+    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 = System::nanoTime;
+    }
+
     /**
      * Builder for {@link ExponentialBackOff}.
      *
@@ -285,7 +305,7 @@ public class ExponentialBackOff implements BackOff {
     public static class Builder {
 
         /** The initial retry interval in milliseconds. */
-        int initialIntervalMillis = DEFAULT_INITIAL_INTERVAL_MILLIS;
+        private int initialIntervalMillis = DEFAULT_INITIAL_INTERVAL_MILLIS;
 
         /**
          * The randomization factor to use for creating a range around the retry interval.
@@ -295,32 +315,53 @@ public class ExponentialBackOff implements BackOff {
          * above the retry interval.
          * </p>
          */
-        double randomizationFactor = DEFAULT_RANDOMIZATION_FACTOR;
+        private double randomizationFactor = DEFAULT_RANDOMIZATION_FACTOR;
 
-        /** The value to multiply the current interval with for each retry attempt. */
+        /**
-        double multiplier = DEFAULT_MULTIPLIER;
+         * The value to multiply the current interval with for each retry attempt.
+         */
+        private 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;
+        private 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;
+        private int maxElapsedTimeMillis = DEFAULT_MAX_ELAPSED_TIME_MILLIS;
 
-        /** Nano clock. */
+        /**
-        NanoClock nanoClock = NanoClock.SYSTEM;
+         * Nano clock.
+         */
+        private NanoClock nanoClock = NanoClock.SYSTEM;
 
         public Builder() {
         }
 
-        /** Builds a new instance of {@link ExponentialBackOff}. */
+        /**
+         * Builds a new instance of {@link ExponentialBackOff}.
+         * */
         public ExponentialBackOff build() {
+            if (initialIntervalMillis <= 0) {
+                throw new IllegalArgumentException();
+            }
+            if (!(0 <= randomizationFactor && randomizationFactor < 1)) {
+                throw new IllegalArgumentException();
+            }
+            if (multiplier < 1) {
+                throw new IllegalArgumentException();
+            }
+            if ((maxIntervalMillis < initialIntervalMillis)) {
+                throw new IllegalArgumentException();
+            }
+            if (maxElapsedTimeMillis <= 0) {
+                throw new IllegalArgumentException();
+            }
             return new ExponentialBackOff(this);
         }
 
@@ -480,7 +521,9 @@ public class ExponentialBackOff implements BackOff {
          * </p>
          */
         public Builder setNanoClock(NanoClock nanoClock) {
-            this.nanoClock = nanoClock; //Preconditions.checkNotNull(nanoClock);
+            if (nanoClock != null) {
+                this.nanoClock = nanoClock;
+            }
             return this;
         }
     }

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

@@ -1,44 +0,0 @@
-/*
- * 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

@@ -5,7 +5,9 @@ import io.netty.handler.codec.http.DefaultFullHttpRequest;
 import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.cookie.ClientCookieDecoder;
 import io.netty.handler.codec.http.cookie.ClientCookieEncoder;
 import io.netty.handler.codec.http.cookie.Cookie;
 import io.netty.handler.codec.http2.HttpConversionUtil;
@@ -16,6 +18,9 @@ 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.HttpHeadersListener;
+import org.xbib.netty.http.client.retry.BackOff;
 
 import java.io.IOException;
 import java.net.ConnectException;
@@ -48,6 +53,8 @@ abstract class BaseTransport implements Transport {
 
     protected SortedMap<Integer, Request> requests;
 
+    protected Throwable throwable;
+
     private Map<Cookie, Boolean> cookieBox;
 
     BaseTransport(Client client, HttpAddress httpAddress) {
@@ -56,43 +63,55 @@ abstract class BaseTransport implements Transport {
         this.requests = new ConcurrentSkipListMap<>();
     }
 
-    @Override
-    public HttpAddress httpAddress() {
-        return httpAddress;
-    }
-
     @Override
     public Transport execute(Request request) throws IOException {
         ensureConnect();
-        // some HTTP 1.1 servers like Elasticsearch do not understand full URIs in HTTP command line
+        if (throwable != null) {
-        String uri = request.httpVersion().majorVersion() < 2 ?
+            return this;
+        }
+        // Some HTTP 1 servers do not understand URIs in HTTP command line in spite of RFC 7230.
+        // The "origin form" requires a "Host" header.
+        // Our algorithm is: use always "origin form" for HTTP 1, use absolute form for HTTP 2.
+        // The reason is that Netty derives the HTTP/2 scheme header from the absolute form.
+        String uri = request.httpVersion().majorVersion() == 1 ?
                 request.base().relativeReference() : request.base().toString();
         FullHttpRequest fullHttpRequest = request.content() == null ?
                 new DefaultFullHttpRequest(request.httpVersion(), request.httpMethod(), uri) :
                 new DefaultFullHttpRequest(request.httpVersion(), request.httpMethod(), uri,
                         request.content());
-        logger.log(Level.INFO, fullHttpRequest.toString());
+        try {
-        Integer streamId = nextStream();
+            Integer streamId = nextStream();
-        if (streamId != null) {
+            if (streamId != null && streamId > 0) {
-            request.headers().add(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(), Integer.toString(streamId));
+                request.headers().set(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(), Integer.toString(streamId));
+            } else {
+                if (request.httpVersion().majorVersion() == 2) {
+                    logger.log(Level.WARNING, "no streamId but HTTP/2 request. Strange!!! " + getClass().getName());
+                }
+            }
+            // add matching cookies from box (previous requests) and new cookies from request builder
+            Collection<Cookie> cookies = new ArrayList<>();
+            cookies.addAll(matchCookiesFromBox(request));
+            cookies.addAll(matchCookies(request));
+            if (!cookies.isEmpty()) {
+                request.headers().set(HttpHeaderNames.COOKIE, ClientCookieEncoder.STRICT.encode(cookies));
+            }
+            // add stream-id and cookie headers
+            fullHttpRequest.headers().set(request.headers());
+            if (streamId != null) {
+                requests.put(streamId, request);
+            }
+            if (channel.isWritable()) {
+                channel.writeAndFlush(fullHttpRequest);
+
+            }
+        } finally {
+            request.close();
         }
-        // add matching cookies from box (previous requests) and new cookies from request builder
-        Collection<Cookie> cookies = new ArrayList<>();
-        cookies.addAll(matchCookiesFromBox(request));
-        cookies.addAll(matchCookies(request));
-        if (!cookies.isEmpty()) {
-            request.headers().set(HttpHeaderNames.COOKIE, ClientCookieEncoder.STRICT.encode(cookies));
-        }
-        // add stream-id and cookie headers
-        fullHttpRequest.headers().set(request.headers());
-        requests.put(streamId, request);
-        logger.log(Level.FINE, () -> "streamId = " + streamId + " writing request = " + fullHttpRequest);
-        channel.writeAndFlush(fullHttpRequest);
         return this;
     }
 
     /**
-     * Experimental.
+     * Experimental method for executing in a wrapping completable future.
      * @param request request
      * @param supplier supplier
      * @param <T> supplier result
@@ -102,44 +121,86 @@ abstract class BaseTransport implements Transport {
     public <T> CompletableFuture<T> execute(Request request,
                                             Function<FullHttpResponse, T> supplier) throws IOException {
         final CompletableFuture<T> completableFuture = new CompletableFuture<>();
-        //request.setExceptionListener(completableFuture::completeExceptionally);
         request.setResponseListener(response -> completableFuture.complete(supplier.apply(response)));
         execute(request);
         return completableFuture;
     }
 
     @Override
-    public synchronized void close() {
+    public synchronized void close() throws IOException {
         get();
-        if (channel != null) {
+        client.releaseChannel(channel);
-            channel.close();
-            channel = null;
-        }
     }
 
-    protected void ensureConnect() throws IOException {
+    @Override
-        if (channel == null) {
+    public boolean isFailed() {
-            try {
+        return throwable != null;
-                channel = client.newChannel(httpAddress);
+    }
-                channel.attr(TRANSPORT_ATTRIBUTE_KEY).set(this);
+
-                awaitSettings();
+    @Override
-            } catch (InterruptedException e) {
+    public Throwable getFailure() {
-                throw new ConnectException("unable to connect to " + httpAddress);
+        return throwable;
+    }
+
+    @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);
+                }
             }
         }
     }
 
-    protected Request continuation(Integer streamId, FullHttpResponse httpResponse) throws URLSyntaxException {
+    private void ensureConnect() throws IOException {
+        if (channel == null) {
+            channel = client.newChannel(httpAddress);
+            if (channel != null) {
+                channel.attr(TRANSPORT_ATTRIBUTE_KEY).set(this);
+                awaitSettings();
+            } else {
+                ConnectException connectException;
+                if (httpAddress != null) {
+                    connectException = new ConnectException("unable to connect to " + httpAddress);
+                } else if (client.hasPooledConnections()){
+                    connectException = new ConnectException("unable to get channel from pool");
+                } else {
+                    // if API misuse
+                    connectException = new ConnectException("unable to get channel");
+                }
+                this.throwable = connectException;
+                this.channel = null;
+                throw connectException;
+            }
+        }
+    }
+
+    protected Request fromStreamId(Integer streamId) {
+        if (streamId == null) {
+            streamId = requests.lastKey();
+        }
+        return requests.get(streamId);
+    }
+
+    protected Request continuation(Request request, FullHttpResponse httpResponse) throws URLSyntaxException {
         if (httpResponse == null) {
             return null;
         }
-        Request request = fromStreamId(streamId);
         if (request == null) {
-            // push promise
+            // push promise or something else
             return null;
         }
         try {
-            if (request.checkRedirect()) {
+            if (request.canRedirect()) {
                 int status = httpResponse.status().code();
                 switch (status) {
                     case 300:
@@ -152,7 +213,7 @@ abstract class BaseTransport implements Transport {
                         String location = httpResponse.headers().get(HttpHeaderNames.LOCATION);
                         location = new PercentDecoder(StandardCharsets.UTF_8.newDecoder()).decode(location);
                         if (location != null) {
-                            logger.log(Level.INFO, "found redirect location: " + location);
+                            logger.log(Level.FINE, "found redirect location: " + location);
                             URL redirUrl = URL.base(request.base()).resolve(location);
                             HttpMethod method = httpResponse.status().code() == 303 ? HttpMethod.GET : request.httpMethod();
                             RequestBuilder newHttpRequestBuilder = Request.builder(method)
@@ -160,45 +221,75 @@ abstract class BaseTransport implements Transport {
                                     .setVersion(request.httpVersion())
                                     .setHeaders(request.headers())
                                     .content(request.content());
-                            // TODO(jprante) convencience to copy pathAndQuery from one request to another
                             request.base().getQueryParams().forEach(pair ->
                                 newHttpRequestBuilder.addParameter(pair.getFirst(), pair.getSecond())
                             );
                             request.cookies().forEach(newHttpRequestBuilder::addCookie);
                             Request newHttpRequest = newHttpRequestBuilder.build();
                             newHttpRequest.setResponseListener(request.getResponseListener());
-                            //newHttpRequest.setExceptionListener(request.getExceptionListener());
                             newHttpRequest.setHeadersListener(request.getHeadersListener());
                             newHttpRequest.setCookieListener(request.getCookieListener());
-                            //newHttpRequest.setPushListener(request.getPushListener());
                             StringBuilder hostAndPort = new StringBuilder();
                             hostAndPort.append(redirUrl.getHost());
                             if (redirUrl.getPort() != null) {
                                 hostAndPort.append(':').append(redirUrl.getPort());
                             }
                             newHttpRequest.headers().set(HttpHeaderNames.HOST, hostAndPort.toString());
-                            logger.log(Level.INFO, "redirect url: " + redirUrl +
+                            logger.log(Level.FINE, "redirect url: " + redirUrl +
                                     " old request: " + request.toString() +
                                     " new request: " + newHttpRequest.toString());
                             return newHttpRequest;
                         }
                         break;
                     default:
-                        logger.log(Level.FINE, "no redirect because of status code " + status);
                         break;
                 }
             }
         } catch (MalformedInputException | UnmappableCharacterException e) {
-            logger.log(Level.WARNING, e.getMessage(), e);
+            this.throwable = e;
         }
         return null;
     }
 
-    protected Request fromStreamId(Integer streamId) {
+    protected Request retry(Request request, FullHttpResponse httpResponse) {
-        if (streamId == null) {
+        if (httpResponse == null) {
-            streamId = requests.lastKey();
+            return null;
         }
-       return requests.get(streamId);
+        if (request == null) {
+            // push promise or something else
+            return null;
+        }
+        if (request.isBackOff()) {
+            BackOff backOff = request.getBackOff() != null ? request.getBackOff() :
+                    client.getClientConfig().getBackOff();
+            int status = httpResponse.status().code();
+            switch (status) {
+                case 403:
+                case 404:
+                case 500:
+                case 502:
+                case 503:
+                case 504:
+                case 507:
+                case 509:
+                    if (backOff != null) {
+                        long millis = backOff.nextBackOffMillis();
+                        if (millis != BackOff.STOP) {
+                            logger.log(Level.FINE, "status = " + status + " backing off request by " + millis + " milliseconds");
+                            try {
+                                Thread.sleep(millis);
+                            } catch (InterruptedException e) {
+                                // ignore
+                            }
+                            return request;
+                        }
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+        return null;
     }
 
     public void setCookieBox(Map<Cookie, Boolean> cookieBox) {
@@ -209,7 +300,7 @@ abstract class BaseTransport implements Transport {
         return cookieBox;
     }
 
-    public void addCookie(Cookie cookie) {
+    private void addCookie(Cookie cookie) {
         if (cookieBox == null) {
             this.cookieBox = Collections.synchronizedMap(new LRUCache<Cookie, Boolean>(32));
         }
@@ -241,7 +332,8 @@ abstract class BaseTransport implements Transport {
         return (secureScheme && cookie.isSecure()) || (!secureScheme && !cookie.isSecure());
     }
 
-    class LRUCache<K, V> extends LinkedHashMap<K, V> {
+    @SuppressWarnings("serial")
+    static class LRUCache<K, V> extends LinkedHashMap<K, V> {
 
         private final int cacheSize;
 

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

@@ -2,18 +2,12 @@ package org.xbib.netty.http.client.transport;
 
 import io.netty.channel.Channel;
 import io.netty.handler.codec.http.FullHttpResponse;
-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;
@@ -27,7 +21,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class Http2Transport extends BaseTransport implements Transport {
+public class Http2Transport extends BaseTransport {
 
     private static final Logger logger = Logger.getLogger(Http2Transport.class.getName());
 
@@ -41,7 +35,9 @@ public class Http2Transport extends BaseTransport implements Transport {
         super(client, httpAddress);
         streamIdCounter = new AtomicInteger(3);
         streamidPromiseMap = new ConcurrentSkipListMap<>();
-        settingsPromise = new CompletableFuture<>();
+        settingsPromise = (httpAddress != null && httpAddress.isSecure()) ||
+                (client.hasPooledConnections() && client.getPool().isSecure()) ?
+                new CompletableFuture<>() : null;
     }
 
     @Override
@@ -69,62 +65,47 @@ public class Http2Transport extends BaseTransport implements Transport {
     public void awaitSettings() {
         if (settingsPromise != null) {
             try {
-                settingsPromise.get(client.getTimeout(), TimeUnit.MILLISECONDS);
+                settingsPromise.get(client.getClientConfig().getReadTimeoutMillis(), TimeUnit.MILLISECONDS);
             } catch (InterruptedException | ExecutionException | TimeoutException e) {
                 settingsPromise.completeExceptionally(e);
             }
-        } else {
-            logger.log(Level.WARNING, "waiting for settings but no promise present");
         }
     }
 
     @Override
     public void responseReceived(Integer streamId, FullHttpResponse fullHttpResponse) {
         if (streamId == null) {
-            logger.log(Level.WARNING, "unexpected message received: " + fullHttpResponse);
+            logger.log(Level.WARNING, "no stream ID, unexpected message received: " + fullHttpResponse);
             return;
         }
         CompletableFuture<Boolean> promise = streamidPromiseMap.get(streamId);
         if (promise == null) {
-            logger.log(Level.WARNING, "response received for unknown stream id " + streamId);
+            logger.log(Level.WARNING, "response received for stream ID " + streamId + " but found no promise");
-        } else {
+            return;
-            Request request = fromStreamId(streamId);
-            if (request != null) {
-                HttpResponseListener responseListener = request.getResponseListener();
-                if (responseListener != null) {
-                    responseListener.onResponse(fullHttpResponse);
-                }
-                try {
-                    request = continuation(streamId, fullHttpResponse);
-                    if (request != null) {
-                        // synchronous call here
-                        client.continuation(this, request);
-                    }
-                } catch (URLSyntaxException | IOException e) {
-                    logger.log(Level.WARNING, e.getMessage(), e);
-                }
-            }
-            // complete origin
-            promise.complete(true);
         }
-    }
-
-    @Override
-    public void headersReceived(Integer streamId, HttpHeaders httpHeaders) {
         Request request = fromStreamId(streamId);
         if (request != null) {
-            HttpHeadersListener httpHeadersListener = request.getHeadersListener();
+            HttpResponseListener responseListener = request.getResponseListener();
-            if (httpHeadersListener != null) {
+            if (responseListener != null) {
-                httpHeadersListener.onHeaders(httpHeaders);
+                responseListener.onResponse(fullHttpResponse);
             }
-            CookieListener cookieListener = request.getCookieListener();
+            try {
-            if (cookieListener != null) {
+                Request retryRequest = retry(request, fullHttpResponse);
-                for (String cookieString : httpHeaders.getAll(HttpHeaderNames.SET_COOKIE)) {
+                if (retryRequest != null) {
-                    Cookie cookie = ClientCookieDecoder.STRICT.decode(cookieString);
+                    // retry transport, wait for completion
-                    cookieListener.onCookie(cookie);
+                    client.retry(this, retryRequest);
+                } else {
+                    Request continueRequest = continuation(request, fullHttpResponse);
+                    if (continueRequest != null) {
+                        // continue with new transport, synchronous call here, wait for completion
+                        client.continuation(this, continueRequest);
+                    }
                 }
+            } catch (URLSyntaxException | IOException e) {
+                logger.log(Level.WARNING, e.getMessage(), e);
             }
         }
+        promise.complete(true);
     }
 
     @Override
@@ -134,16 +115,25 @@ public class Http2Transport extends BaseTransport implements Transport {
     }
 
     @Override
-    public void awaitResponse(Integer streamId) {
+    public void awaitResponse(Integer streamId) throws IOException {
         if (streamId == null) {
             return;
         }
+        if (throwable != null) {
+            return;
+        }
         CompletableFuture<Boolean> promise = streamidPromiseMap.get(streamId);
         if (promise != null) {
             try {
-                promise.get(client.getTimeout(), TimeUnit.MILLISECONDS);
+                long millis = client.getClientConfig().getReadTimeoutMillis();
+                Request request = fromStreamId(streamId);
+                if (request != null && request.getTimeoutInMillis() > 0) {
+                    millis = request.getTimeoutInMillis();
+                }
+                promise.get(millis, TimeUnit.MILLISECONDS);
             } catch (InterruptedException | ExecutionException | TimeoutException e) {
-                logger.log(Level.WARNING, "streamId=" + streamId + " " + e.getMessage(), e);
+                this.throwable = e;
+                throw new IOException(e);
             } finally {
                 streamidPromiseMap.remove(streamId);
             }
@@ -153,7 +143,14 @@ public class Http2Transport extends BaseTransport implements Transport {
     @Override
     public Transport get() {
         for (Integer streamId : streamidPromiseMap.keySet()) {
-            awaitResponse(streamId);
+            try {
+                awaitResponse(streamId);
+            } catch (IOException e) {
+                notifyRequest(streamId, e);
+            }
+        }
+        if (throwable != null) {
+            streamidPromiseMap.clear();
         }
         return this;
     }
@@ -165,10 +162,32 @@ public class Http2Transport extends BaseTransport implements Transport {
         }
     }
 
+    /**
+     * The underlying network layer failed, not possible to know the request.
+     * So we fail all (open) promises.
+     * @param throwable the exception
+     */
     @Override
     public void fail(Throwable throwable) {
+        // fail fast, do not fail more than once
+        if (this.throwable != null) {
+            return;
+        }
+        this.throwable = throwable;
         for (CompletableFuture<Boolean> promise : streamidPromiseMap.values()) {
             promise.completeExceptionally(throwable);
         }
     }
+
+    /**
+     * Try to notify request about failure.
+     * @param streamId stream ID
+     * @param throwable the exception
+     */
+    private void notifyRequest(Integer streamId, Throwable throwable) {
+        Request request = fromStreamId(streamId);
+        if (request != null && request.getCompletableFuture() != null) {
+            request.getCompletableFuture().completeExceptionally(throwable);
+        }
+    }
 }

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

@@ -2,18 +2,12 @@ package org.xbib.netty.http.client.transport;
 
 import io.netty.channel.Channel;
 import io.netty.handler.codec.http.FullHttpResponse;
-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;
@@ -27,7 +21,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class HttpTransport extends BaseTransport implements Transport {
+public class HttpTransport extends BaseTransport {
 
     private static final Logger logger = Logger.getLogger(HttpTransport.class.getName());
 
@@ -43,7 +37,7 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public Integer nextStream() {
-        Integer streamId = sequentialCounter.getAndAdd(1);
+        Integer streamId = sequentialCounter.getAndIncrement();
         if (streamId == Integer.MIN_VALUE) {
             // reset if overflow, Java wraps atomic integers to Integer.MIN_VALUE
             sequentialCounter.set(0);
@@ -71,9 +65,18 @@ public class HttpTransport extends BaseTransport implements Transport {
             }
         }
         try {
-            request = continuation(null, fullHttpResponse);
+            Request retryRequest = retry(request, fullHttpResponse);
-            if (request != null) {
+            if (retryRequest != null) {
-                client.continuation(this, request);
+                // retry transport, wait for completion
+                client.retry(this, retryRequest);
+                retryRequest.close();
+            } else {
+                Request continueRequest = continuation(request, fullHttpResponse);
+                if (continueRequest != null) {
+                    // continue with new transport, synchronous call here, wait for completion
+                    client.continuation(this, continueRequest);
+                    continueRequest.close();
+                }
             }
         } catch (URLSyntaxException | IOException e) {
             logger.log(Level.WARNING, e.getMessage(), e);
@@ -86,40 +89,25 @@ 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) {
+    public void awaitResponse(Integer streamId) throws IOException {
         if (streamId == null) {
             return;
         }
+        if (throwable != null) {
+            return;
+        }
         CompletableFuture<Boolean> promise = sequentialPromiseMap.get(streamId);
         if (promise != null) {
             try {
-                promise.get(client.getTimeout(), TimeUnit.MILLISECONDS);
+                promise.get(client.getClientConfig().getReadTimeoutMillis(), TimeUnit.MILLISECONDS);
             } catch (InterruptedException | ExecutionException | TimeoutException e) {
-                logger.log(Level.WARNING, "streamId=" + streamId + " " + e.getMessage(), e);
+                this.throwable = e;
+                throw new IOException(e);
             } finally {
                 sequentialPromiseMap.remove(streamId);
             }
@@ -128,8 +116,15 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public Transport get() {
-        for (Integer streamId : sequentialPromiseMap.keySet()) {
+        try {
-            awaitResponse(streamId);
+            for (Integer streamId : sequentialPromiseMap.keySet()) {
+                awaitResponse(streamId);
+                client.releaseChannel(channel);
+            }
+        } catch (IOException e) {
+            logger.log(Level.WARNING, e.getMessage(), e);
+        } finally {
+            sequentialPromiseMap.clear();
         }
         return this;
     }
@@ -143,9 +138,9 @@ public class HttpTransport extends BaseTransport implements Transport {
 
     @Override
     public void fail(Throwable throwable) {
+        this.throwable = throwable;
         for (CompletableFuture<Boolean> promise : sequentialPromiseMap.values()) {
             promise.completeExceptionally(throwable);
         }
     }
-
 }

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

@@ -7,7 +7,6 @@ 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 java.io.IOException;
@@ -19,8 +18,6 @@ public interface Transport {
 
     AttributeKey<Transport> TRANSPORT_ATTRIBUTE_KEY = AttributeKey.valueOf("transport");
 
-    HttpAddress httpAddress();
-
     Transport execute(Request request) throws IOException;
 
     <T> CompletableFuture<T> execute(Request request, Function<FullHttpResponse, T> supplier) throws IOException;
@@ -41,7 +38,7 @@ public interface Transport {
 
     void pushPromiseReceived(Integer streamId, Integer promisedStreamId, Http2Headers headers);
 
-    void awaitResponse(Integer streamId);
+    void awaitResponse(Integer streamId) throws IOException;
 
     Transport get();
 
@@ -49,5 +46,9 @@ public interface Transport {
 
     void fail(Throwable throwable);
 
-    void close();
+    boolean isFailed();
+
+    Throwable getFailure();
+
+    void close() throws IOException;
 }

src/main/java/org/xbib/netty/http/client/util/NetworkUtils.java

@@ -395,10 +395,8 @@ public class NetworkUtils {
             if (predicate.test(networkInterface)) {
                 networkInterfaces.add(networkInterface);
                 Enumeration<NetworkInterface> subInterfaces = networkInterface.getSubInterfaces();
-                if (subInterfaces.hasMoreElements()) {
+                while (subInterfaces.hasMoreElements()) {
-                    while (subInterfaces.hasMoreElements()) {
+                    networkInterfaces.add(subInterfaces.nextElement());
-                        networkInterfaces.add(subInterfaces.nextElement());
-                    }
                 }
             }
         }

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

@@ -26,7 +26,7 @@ public class CompletableFutureTest {
             final Function<FullHttpResponse, String> httpResponseStringFunction = response ->
                     response.content().toString(StandardCharsets.UTF_8);
             Request request = Request.get()
-                    .url("http://alkmene.hbz-nrw.de/repository/org/xbib/content/2.0.0-SNAPSHOT/maven-metadata-local.xml")
+                    .url("https://repo.maven.apache.org/maven2/org/xbib/netty-http-client/maven-metadata.xml.sha1")
                     .build();
             CompletableFuture<String> completableFuture = client.execute(request, httpResponseStringFunction)
                     .exceptionally(Throwable::getMessage)

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

@@ -17,15 +17,14 @@ public class ConscryptTest extends LoggingBase {
     @Test
     public void testConscrypt() throws IOException {
         Client client = Client.builder()
-                .enableDebug()
                 .setJdkSslProvider()
                 .setSslContextProvider(Conscrypt.newProvider())
                 .build();
         logger.log(Level.INFO, client.getClientConfig().toString());
         try {
             Request request = Request.get()
-                    .url("https://fl-test.hbz-nrw.de")
+                    .url("https://xbib.org")
-                    .setVersion("HTTP/2.0")
+                    .setVersion("HTTP/1.1")
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);

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

@@ -26,7 +26,7 @@ public class CookieSetterHttpBinTest extends LoggingBase {
      *     }
      *   }
      * </pre>
-     * @throws Exception
+     * @throws IOException if test fails
      */
     @Test
     public void testHttpBinCookies() throws IOException {

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

@@ -83,7 +83,7 @@ public class ElasticsearchTest extends LoggingBase {
                 .build()
                 .setResponseListener(fullHttpResponse ->
                     logger.log(Level.FINE, "status = " + fullHttpResponse.status() +
-                            " counter = " + count.incrementAndGet() +
+                            " counter = " + count.getAndIncrement() +
                             " response body = " + fullHttpResponse.content().toString(StandardCharsets.UTF_8)));
     }
 

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

@@ -1,24 +1,34 @@
 package org.xbib.netty.http.client.test;
 
 import io.netty.handler.codec.http.HttpMethod;
+import org.junit.After;
+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.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class Http1Test {
+public class Http1Test extends LoggingBase {
 
     private static final Logger logger = Logger.getLogger(Http1Test.class.getName());
 
+    @After
+    public void checkThreads() {
+        Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
+        logger.log(Level.INFO, "threads = " + threadSet.size() );
+        threadSet.forEach( thread -> logger.log(Level.INFO, thread.toString()));
+    }
+
     @Test
     public void testHttp1() throws Exception {
         Client client = new Client();
         try {
-            Request request = Request.get().url("http://fl.hbz-nrw.de").build()
+            Request request = Request.get().url("http://xbib.org").build()
                     .setResponseListener(msg -> logger.log(Level.INFO, "got response: " +
                             msg.headers().entries() +
                             msg.content().toString(StandardCharsets.UTF_8) +
@@ -30,26 +40,29 @@ public class Http1Test {
     }
 
     @Test
-    public void testHttp1ParallelRequests() throws IOException {
+    @Ignore
-        Client client = new Client();
+    public void testParallelRequests() throws IOException {
+        Client client = Client.builder().enableDebug().build();
         try {
             Request request1 = Request.builder(HttpMethod.GET)
-                    .url("http://fl.hbz-nrw.de").setVersion("HTTP/1.1")
+                    .url("http://xbib.org").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")
+                    .url("http://xbib.org").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);
+            for (int i = 0; i < 10; i++) {
-            client.execute(request2);
+                client.execute(request1);
+                client.execute(request2);
+            }
 
         } finally {
             client.shutdownGracefully();
@@ -57,7 +70,8 @@ public class Http1Test {
     }
 
     @Test
-    public void testTwoTransports() throws Exception {
+    @Ignore
+    public void testSequentialRequests() throws Exception {
         Client client = Client.builder().enableDebug().build();
         try {
             Request request1 = Request.get().url("http://xbib.org").build()

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

@@ -11,25 +11,39 @@ import java.nio.charset.StandardCharsets;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class Http2Test {
+public class Http2Test extends LoggingBase {
 
     private static final Logger logger = Logger.getLogger(Http2Test.class.getName());
 
     /**
+     * Problems with akamai:
+     *
+     * 2018-03-07 16:02:52.385 FEIN    [client] io.netty.handler.codec.http2.Http2FrameLogger logRstStream
+     * [id: 0x57cc65bb, L:/10.1.1.94:52834 - R:http2.akamai.com/104.94.191.203:443] INBOUND RST_STREAM: streamId=2 errorCode=8
+     * 2018-03-07 16:02:52.385 FEIN    [client] io.netty.handler.codec.http2.Http2FrameLogger logGoAway
+     * [id: 0x57cc65bb, L:/10.1.1.94:52834 - R:http2.akamai.com/104.94.191.203:443] OUTBOUND GO_AWAY: lastStreamId=2 errorCode=0 length=0 bytes=
+     *
+     * demo/h2_demo_frame.html sends no content, only a push promise, and does not continue
+     *
+     * @throws IOException
      */
     @Test
+    @Ignore
     public void testAkamai() throws IOException {
-        Client client = Client.builder().enableDebug().build();
+        Client client = Client.builder()
+                .enableDebug()
+                .addServerNameForIdentification("http2.akamai.com")
+                .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 -> {
+                    .setResponseListener(msg -> {
-                        String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
+                        String response = msg.content().toString(StandardCharsets.UTF_8);
-                        logger.log(Level.INFO, "status = " + fullHttpResponse.status()
+                        logger.log(Level.INFO, "status = " + msg.status() +
-                                + " response body = " + response);
+                                msg.headers().entries() + " " + response);
                     });
             client.execute(request).get();
         } finally {
@@ -55,17 +69,18 @@ public class Http2Test {
 
     @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()
-        Client client = Client.builder().enableDebug().build();
+                .enableDebug()
+                .addServerNameForIdentification("http2-push.io")
+                .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) +
+                            //msg.content().toString(StandardCharsets.UTF_8) +
                             " status=" + msg.status().code()));
             client.execute(request).get();
 
@@ -75,7 +90,7 @@ public class Http2Test {
     }
 
     @Test
-    public void testWebtideTwoRequestsOnSameConnection() {
+    public void testWebtideTwoRequestsOnSameConnection() throws IOException {
         Client client = new Client();
         try {
             Request request1 = Request.builder(HttpMethod.GET)
@@ -95,8 +110,6 @@ public class Http2Test {
                             " status=" + msg.status().code()));
 
             client.execute(request1).execute(request2);
-        } catch (IOException e) {
-            //
         } finally {
             client.shutdownGracefully();
         }

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

@@ -0,0 +1,28 @@
+package org.xbib.netty.http.client.test;
+
+import org.junit.After;
+import org.junit.Test;
+import org.xbib.netty.http.client.Client;
+
+import java.io.IOException;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class LeakTest {
+
+    private static final Logger logger = Logger.getLogger(LeakTest.class.getName());
+
+    @After
+    public void checkThreads() {
+        Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
+        logger.log(Level.INFO, "threads = " + threadSet.size() );
+        threadSet.forEach( thread -> logger.log(Level.INFO, thread.toString()));
+    }
+
+    @Test
+    public void testForLeaks() throws IOException, InterruptedException {
+        Client client = new Client();
+        client.shutdownGracefully();
+    }
+}

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

@@ -17,7 +17,7 @@ public class LoggingBase {
         Handler handler = new ConsoleHandler();
         handler.setFormatter(new SimpleFormatter());
         rootLogger.addHandler(handler);
-        rootLogger.setLevel(Level.INFO);
+        rootLogger.setLevel(Level.ALL);
         for (Handler h : rootLogger.getHandlers()) {
             handler.setFormatter(new SimpleFormatter());
             h.setLevel(Level.ALL);

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

@@ -0,0 +1,65 @@
+package org.xbib.netty.http.client.test;
+
+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 java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class PooledClientTest extends LoggingBase {
+
+    private static final Logger logger = Logger.getLogger("");
+
+    @Test
+    public void testPooledClientWithSingleNode() throws IOException {
+        int loop = 10;
+        HttpAddress httpAddress = HttpAddress.http1("xbib.org", 80);
+        Client client = Client.builder()
+                .addPoolNode(httpAddress)
+                .setPoolSecure(httpAddress.isSecure())
+                .setPoolNodeConnectionLimit(16)
+                .build();
+        AtomicInteger count = new AtomicInteger();
+        try {
+            int threads = 16;
+            ExecutorService executorService = Executors.newFixedThreadPool(threads);
+            for (int n = 0; n < threads; n++) {
+                executorService.submit(() -> {
+                    try {
+                        logger.log(Level.INFO, "starting " + Thread.currentThread());
+                        for (int i = 0; i < loop; i++) {
+                            Request request = Request.get()
+                                    .url("http://xbib.org/repository/")
+                                    .setVersion("HTTP/1.1")
+                                    .build()
+                                    .setResponseListener(fullHttpResponse -> {
+                                        String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);
+                                        //logger.log(Level.INFO, "status = " + fullHttpResponse.status() + " response body = " + response);
+                                    });
+                            client.pooledExecute(request).get();
+                            count.getAndIncrement();
+                        }
+                        logger.log(Level.INFO, "done " + Thread.currentThread());
+                    } catch (IOException e) {
+                        logger.log(Level.WARNING, e.getMessage(), e);
+                    }
+                });
+            }
+            executorService.shutdown();
+            executorService.awaitTermination(60, TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
+            logger.log(Level.WARNING, e.getMessage(), e);
+        } finally {
+            client.shutdownGracefully();
+        }
+        logger.log(Level.INFO, "count = " + count.get());
+    }
+}

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

@@ -88,11 +88,11 @@ public class XbibTest extends LoggingBase {
     @Test
     public void testXbibOrgWithVeryShortReadTimeout() throws IOException {
         Client httpClient = Client.builder()
-                .setReadTimeoutMillis(50)
                 .build();
         try {
             httpClient.execute(Request.get()
                     .url("http://xbib.org")
+                    .setTimeoutInMillis(10)
                     .build()
                     .setResponseListener(fullHttpResponse -> {
                         String response = fullHttpResponse.content().toString(StandardCharsets.UTF_8);

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

@@ -13,13 +13,14 @@ import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.epoll.EpollSocketChannel;
 import io.netty.channel.socket.SocketChannel;
 
+import io.netty.handler.codec.http.HttpVersion;
 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 org.xbib.netty.http.client.pool.BoundedChannelPool;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -34,6 +35,7 @@ import java.util.concurrent.atomic.LongAdder;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+@Ignore
 public class EpollTest {
 
     private static final Logger logger = Logger.getLogger(EpollTest.class.getName());
@@ -74,7 +76,8 @@ public class EpollTest {
             .option(ChannelOption.SO_KEEPALIVE, true)
             .option(ChannelOption.SO_REUSEADDR, true)
             .option(ChannelOption.TCP_NODELAY, true);
-        channelPool = new SimpleChannelPool<>(semaphore, NODES, bootstrap, null, 0);
+        channelPool = new BoundedChannelPool<>(semaphore, HttpVersion.HTTP_1_1,false,
+                NODES, bootstrap, null, 0);
         channelPool.prepare(CONCURRENCY);
     }
 
@@ -85,7 +88,6 @@ public class EpollTest {
         mockEpollServer.close();
     }
 
-    @Ignore
     @Test
     public void testPoolEpoll() throws Exception {
         LongAdder longAdder = new LongAdder();

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

@@ -12,12 +12,13 @@ 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 io.netty.handler.codec.http.HttpVersion;
 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 org.xbib.netty.http.client.pool.BoundedChannelPool;
 
 import java.util.Collections;
 import java.util.List;
@@ -72,7 +73,8 @@ public class NioTest {
             .option(ChannelOption.SO_KEEPALIVE, true)
             .option(ChannelOption.SO_REUSEADDR, true)
             .option(ChannelOption.TCP_NODELAY, true);
-        channelPool = new SimpleChannelPool<>(semaphore, NODES, bootstrap, null, 0);
+        channelPool = new BoundedChannelPool<>(semaphore, HttpVersion.HTTP_1_1,false,
+                NODES, bootstrap, null, 0);
         channelPool.prepare(CONCURRENCY);
     }
 

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

@@ -2,6 +2,14 @@ package org.xbib.netty.http.client.test.pool;
 
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
+import io.netty.handler.codec.http.HttpVersion;
+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.BoundedChannelPool;
+import org.xbib.netty.http.client.pool.Pool;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -17,21 +25,13 @@ 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 {
+public class PoolTest {
 
-    private static final Logger logger = Logger.getLogger(SimplePoolTest.class.getName());
+    private static final Logger logger = Logger.getLogger(PoolTest.class.getName());
 
     private static final int TEST_STEP_TIME_SECONDS = 50;
 
@@ -51,14 +51,14 @@ public class SimplePoolTest {
                 });
     }
 
-    public SimplePoolTest(int concurrencyLevel, int nodeCount) {
+    public PoolTest(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(),
+        try (Pool<Channel> pool = new BoundedChannelPool<>(new Semaphore(concurrencyLevel), HttpVersion.HTTP_1_1, false,
-                        null, 0)) {
+                nodes, new Bootstrap(), null, 0)) {
             int n = Runtime.getRuntime().availableProcessors();
             ExecutorService executorService = Executors.newFixedThreadPool(n);
             for(int i = 0; i < n; i ++) {

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

@@ -3,7 +3,6 @@ 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;
@@ -136,7 +135,7 @@ public class ExponentialBackOffTest {
         assertEquals(testMaxInterval, backOffPolicy.getCurrentIntervalMillis());
     }
 
-    static class MyNanoClock implements NanoClock {
+    static class MyNanoClock implements ExponentialBackOff.NanoClock {
 
         private int i = 0;
         private long startSeconds;

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

@@ -23,11 +23,13 @@ public class MockBackOff implements BackOff {
     /** Number of tries so far. */
     private int numTries;
 
-    public void reset() throws IOException {
+    @Override
+    public void reset() {
         numTries = 0;
     }
 
-    public long nextBackOffMillis() throws IOException {
+    @Override
+    public long nextBackOffMillis() {
         if (numTries >= maxTries || backOffMillis == STOP) {
             return STOP;
         }

src/test/java/org/xbib/netty/http/client/test/simple/SimpleHttp1Test.java

@@ -1,11 +1,9 @@
 package org.xbib.netty.http.client.test.simple;
 
 import io.netty.bootstrap.Bootstrap;
-import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInitializer;
-import io.netty.channel.ChannelPromise;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.SimpleChannelInboundHandler;
 import io.netty.channel.nio.NioEventLoopGroup;
@@ -20,11 +18,8 @@ import io.netty.handler.codec.http.HttpHeaderValues;
 import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpVersion;
-import io.netty.handler.codec.http2.Http2Settings;
-import io.netty.handler.codec.http2.HttpConversionUtil;
-import io.netty.handler.logging.LogLevel;
-import io.netty.handler.logging.LoggingHandler;
 import io.netty.util.AttributeKey;
+import org.junit.After;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -32,6 +27,7 @@ import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
@@ -46,17 +42,26 @@ public class SimpleHttp1Test {
 
     private static final Logger logger = Logger.getLogger(SimpleHttp1Test.class.getName());
 
+    @After
+    public void checkThreads() {
+        Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
+        logger.log(Level.INFO, "threads = " + threadSet.size() );
+        threadSet.forEach( thread -> {
+            if (thread.getName().equals("ObjectCleanerThread")) {
+                logger.log(Level.INFO, thread.toString());
+            }
+        });
+    }
+
     @Test
     public void testHttp1() throws Exception {
         Client client = new Client();
         try {
-            HttpTransport transport = client.newTransport("fl.hbz-nrw.de", 80);
+            HttpTransport transport = client.newTransport("xbib.org", 80);
             transport.onResponse(string -> logger.log(Level.INFO, "got messsage: " + string));
             transport.connect();
-            transport.awaitSettings();
             sendRequest(transport);
-            transport.awaitResponses();
+            transport.awaitResponse();
-            transport.close();
         } finally {
             client.shutdown();
         }
@@ -67,20 +72,18 @@ public class SimpleHttp1Test {
         if (channel == null) {
             return;
         }
-        Integer streamId = transport.nextStream();
         String host = transport.inetSocketAddress().getHostString();
         int port = transport.inetSocketAddress().getPort();
-        String uri = "https://" + host + ":" + port;
+        String uri = "http://" + host + ":" + port;
         FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, uri);
         request.headers().add(HttpHeaderNames.HOST, host + ":" + port);
         request.headers().add(HttpHeaderNames.USER_AGENT, "Java");
         request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
         request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
-        if (streamId != null) {
-            request.headers().add(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(), Integer.toString(streamId));
-        }
         logger.log(Level.INFO, () -> "writing request = " + request);
-        channel.writeAndFlush(request);
+        if (channel.isWritable()) {
+            channel.writeAndFlush(request);
+        }
     }
 
     private AttributeKey<HttpTransport> TRANSPORT_ATTRIBUTE_KEY = AttributeKey.valueOf("transport");
@@ -115,16 +118,14 @@ public class SimpleHttp1Test {
             return bootstrap;
         }
 
-        Initializer initializer() {
-            return initializer;
-        }
-
-        HttpResponseHandler responseHandler() {
-            return httpResponseHandler;
-        }
-
         void shutdown() {
+            close();
             eventLoopGroup.shutdownGracefully();
+            try {
+                eventLoopGroup.awaitTermination(10L, TimeUnit.SECONDS);
+            } catch (InterruptedException e) {
+                logger.log(Level.WARNING, e.getMessage(), e);
+            }
         }
 
         HttpTransport newTransport(String host, int port) {
@@ -133,18 +134,11 @@ public class SimpleHttp1Test {
             return transport;
         }
 
-        List<HttpTransport> transports() {
+        synchronized void close() {
-            return transports;
-        }
-
-        void close(HttpTransport transport) {
-            transports.remove(transport);
-        }
-
-        void close() {
             for (HttpTransport transport : transports) {
                 transport.close();
             }
+            transports.clear();
         }
     }
 
@@ -165,10 +159,6 @@ public class SimpleHttp1Test {
             this.inetSocketAddress = inetSocketAddress;
         }
 
-        Client client() {
-            return client;
-        }
-
         InetSocketAddress inetSocketAddress() {
             return inetSocketAddress;
         }
@@ -176,52 +166,33 @@ public class SimpleHttp1Test {
         void connect() throws InterruptedException {
             channel = client.bootstrap().connect(inetSocketAddress).sync().await().channel();
             channel.attr(TRANSPORT_ATTRIBUTE_KEY).set(this);
+            promise = new CompletableFuture<>();
         }
 
         Channel channel() {
             return channel;
         }
 
-        Integer nextStream() {
-            promise = new CompletableFuture<>();
-            return null;
-        }
-
         void onResponse(ResponseWriter responseWriter) {
             this.responseWriter = responseWriter;
         }
 
-        void settingsReceived(Channel channel, Http2Settings http2Settings) {
+        void responseReceived(FullHttpResponse msg) {
-        }
+            if (responseWriter != null) {
-
+                responseWriter.write(msg.content().toString(StandardCharsets.UTF_8));
-        void awaitSettings() {
-        }
-
-        void responseReceived(Integer streamId, String message) {
-            if (promise == null) {
-                logger.log(Level.WARNING, "message received for unknown stream id " + streamId);
-            } else {
-                if (responseWriter != null) {
-                    responseWriter.write(message);
-                }
             }
         }
-        void awaitResponse(Integer streamId) {
+
+        void awaitResponse() {
             if (promise != null) {
                 try {
-                    logger.log(Level.INFO, "waiting for response");
                     promise.get(5, TimeUnit.SECONDS);
-                    logger.log(Level.INFO, "response received");
                 } catch (InterruptedException | ExecutionException | TimeoutException e) {
                     logger.log(Level.WARNING, e.getMessage(), e);
                 }
             }
         }
 
-        void awaitResponses() {
-            awaitResponse(null);
-        }
-
         void complete() {
             if (promise != null) {
                 promise.complete(true);
@@ -238,7 +209,6 @@ public class SimpleHttp1Test {
             if (channel != null) {
                 channel.close();
             }
-            client.close(this);
         }
     }
 
@@ -252,7 +222,6 @@ public class SimpleHttp1Test {
 
         @Override
         protected void initChannel(SocketChannel ch) {
-            ch.pipeline().addLast(new TrafficLoggingHandler());
             ch.pipeline().addLast(new HttpClientCodec());
             ch.pipeline().addLast(new HttpObjectAggregator(1048576));
             ch.pipeline().addLast(httpResponseHandler);
@@ -265,7 +234,7 @@ public class SimpleHttp1Test {
         protected void channelRead0(ChannelHandlerContext ctx, FullHttpResponse msg) {
             HttpTransport transport = ctx.channel().attr(TRANSPORT_ATTRIBUTE_KEY).get();
             if (msg.content().isReadable()) {
-                transport.responseReceived(null, msg.content().toString(StandardCharsets.UTF_8));
+                transport.responseReceived(msg);
             }
         }
 
@@ -290,35 +259,4 @@ public class SimpleHttp1Test {
             ctx.channel().close();
         }
     }
-
-    class TrafficLoggingHandler extends LoggingHandler {
-
-        TrafficLoggingHandler() {
-            super("client", LogLevel.INFO);
-        }
-
-        @Override
-        public void channelRegistered(ChannelHandlerContext ctx) {
-            ctx.fireChannelRegistered();
-        }
-
-        @Override
-        public void channelUnregistered(ChannelHandlerContext ctx) {
-            ctx.fireChannelUnregistered();
-        }
-
-        @Override
-        public void flush(ChannelHandlerContext ctx) {
-            ctx.flush();
-        }
-
-        @Override
-        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
-            if (msg instanceof ByteBuf && !((ByteBuf) msg).isReadable()) {
-                ctx.write(msg, promise);
-            } else {
-                super.write(ctx, msg, promise);
-            }
-        }
-    }
 }