聊聊JerseyEurekaHttpClient的参数

序

本文主要研究一下JerseyEurekaHttpClient的参数

JerseyEurekaHttpClientFactory

eureka-client-1.8.8-sources.jar!/com/netflix/discovery/shared/transport/jersey/JerseyEurekaHttpClientFactory.java

        private JerseyEurekaHttpClientFactory buildLegacy(Map<String, String> additionalHeaders, boolean systemSSL) {
            EurekaJerseyClientBuilder clientBuilder = new EurekaJerseyClientBuilder()
                    .withClientName(clientName)
                    .withUserAgent("Java-EurekaClient")
                    .withConnectionTimeout(connectionTimeout)
                    .withReadTimeout(readTimeout)
                    .withMaxConnectionsPerHost(maxConnectionsPerHost)
                    .withMaxTotalConnections(maxTotalConnections)
                    .withConnectionIdleTimeout((int) connectionIdleTimeout)
                    .withEncoderWrapper(encoderWrapper)
                    .withDecoderWrapper(decoderWrapper);

            if (systemSSL) {
                clientBuilder.withSystemSSLConfiguration();
            } else if (sslContext != null) {
                clientBuilder.withCustomSSL(sslContext);
            }
            
            if (hostnameVerifier != null) {
                clientBuilder.withHostnameVerifier(hostnameVerifier);
            }

            EurekaJerseyClient jerseyClient = clientBuilder.build();
            ApacheHttpClient4 discoveryApacheClient = jerseyClient.getClient();
            addFilters(discoveryApacheClient);

            return new JerseyEurekaHttpClientFactory(jerseyClient, additionalHeaders);
        }

这里开业看到build的时候，指定了connectionTimeout、readTimeout、maxConnectionsPerHost、maxTotalConnections、connectionIdleTimeout参数。

EurekaJerseyClientImpl

eureka-client-1.8.8-sources.jar!/com/netflix/discovery/shared/transport/jersey/EurekaJerseyClientImpl.java

    public EurekaJerseyClientImpl(int connectionTimeout, int readTimeout, final int connectionIdleTimeout,
                                  ClientConfig clientConfig) {
        try {
            jerseyClientConfig = clientConfig;
            apacheHttpClient = ApacheHttpClient4.create(jerseyClientConfig);
            HttpParams params = apacheHttpClient.getClientHandler().getHttpClient().getParams();

            HttpConnectionParams.setConnectionTimeout(params, connectionTimeout);
            HttpConnectionParams.setSoTimeout(params, readTimeout);

            this.apacheHttpClientConnectionCleaner = new ApacheHttpClientConnectionCleaner(apacheHttpClient, connectionIdleTimeout);
        } catch (Throwable e) {
            throw new RuntimeException("Cannot create Jersey client", e);
        }
    }
    
    public EurekaJerseyClient build() {
            MyDefaultApacheHttpClient4Config config = new MyDefaultApacheHttpClient4Config();
            try {
                return new EurekaJerseyClientImpl(connectionTimeout, readTimeout, connectionIdleTimeout, config);
            } catch (Throwable e) {
                throw new RuntimeException("Cannot create Jersey client ", e);
            }
        }

        class MyDefaultApacheHttpClient4Config extends DefaultApacheHttpClient4Config {
            MyDefaultApacheHttpClient4Config() {
                MonitoredConnectionManager cm;

                if (systemSSL) {
                    cm = createSystemSslCM();
                } else if (sslContext != null || hostnameVerifier != null || trustStoreFileName != null) {
                    cm = createCustomSslCM();
                } else {
                    cm = createDefaultSslCM();
                }

                if (proxyHost != null) {
                    addProxyConfiguration(cm);
                }

                DiscoveryJerseyProvider discoveryJerseyProvider = new DiscoveryJerseyProvider(encoderWrapper, decoderWrapper);
                getSingletons().add(discoveryJerseyProvider);

                // Common properties to all clients
                cm.setDefaultMaxPerRoute(maxConnectionsPerHost);
                cm.setMaxTotal(maxTotalConnections);
                getProperties().put(ApacheHttpClient4Config.PROPERTY_CONNECTION_MANAGER, cm);

                String fullUserAgentName = (userAgent == null ? clientName : userAgent) + "/v" + buildVersion();
                getProperties().put(CoreProtocolPNames.USER_AGENT, fullUserAgentName);

                // To pin a client to specific server in case redirect happens, we handle redirects directly
                // (see DiscoveryClient.makeRemoteCall methods).
                getProperties().put(PROPERTY_FOLLOW_REDIRECTS, Boolean.FALSE);
                getProperties().put(ClientPNames.HANDLE_REDIRECTS, Boolean.FALSE);
            }
            //......
        }            

其中可以看到maxConnectionsPerHost以及maxTotalConnections是配置在MonitoredConnectionManager；而connectionTimeout、readTimeout、connectionIdleTimeout则是配置在apache http client的HttpConnectionParams上。

参数配置

eureka-client-1.8.8-sources.jar!/com/netflix/discovery/shared/transport/EurekaClientFactoryBuilder.java

    public B withClientConfig(EurekaClientConfig clientConfig) {
        withClientAccept(EurekaAccept.fromString(clientConfig.getClientDataAccept()));
        withAllowRedirect(clientConfig.allowRedirects());
        withConnectionTimeout(clientConfig.getEurekaServerConnectTimeoutSeconds() * 1000);
        withReadTimeout(clientConfig.getEurekaServerReadTimeoutSeconds() * 1000);
        withMaxConnectionsPerHost(clientConfig.getEurekaServerTotalConnectionsPerHost());
        withMaxTotalConnections(clientConfig.getEurekaServerTotalConnections());
        withConnectionIdleTimeout(clientConfig.getEurekaConnectionIdleTimeoutSeconds() * 1000);
        withEncoder(clientConfig.getEncoderName());
        return withDecoder(clientConfig.getDecoderName(), clientConfig.getClientDataAccept());
    }

可以看到这里从EurekaClientConfig读取，其映射关系如下：

属性	配置	默认值	说明
connectionTimeout	eureka.client.eureka-server-connect-timeout-seconds	5	Indicates how long to wait (in seconds) before a connection to eureka server needs to timeout. Note that the connections in the client are pooled by org.apache.http.client.HttpClient and this setting affects the actual connection creation and also the wait time to get the connection from the pool.
readTimeout	eureka.client.eureka-server-read-timeout-seconds	8	Indicates how long to wait (in seconds) before a read from eureka server needs to timeout.
maxConnectionsPerHost	eureka.client.eureka-server-total-connections-per-host	50	Gets the total number of connections that is allowed from eureka client to a eureka server host.
maxTotalConnections	eureka.client.eureka-server-total-connections	200	Gets the total number of connections that is allowed from eureka client to all eureka servers.
connectionIdleTimeout	eureka.client.eureka-connection-idle-timeout-seconds	30	Indicates how much time (in seconds) that the HTTP connections to eureka server can stay idle before it can be closed. In the AWS environment, it is recommended that the values is 30 seconds or less, since the firewall cleans up the connection information after a few mins leaving the connection hanging in limbo

小结

可以通过eureka-server-connect-timeout-seconds、eureka-server-read-timeout-seconds、eureka-server-total-connections-per-host、eureka-server-total-connections、eureka-connection-idle-timeout-seconds参数来配置及管理eureka client请求eureka server的http连接。

doc

• EurekaJerseyClientImpl