聊聊JerseyEurekaHttpClient的參數

序

本文主要研究一下JerseyEurekaHttpClient的參數

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);
        }

這裏開業看到build的時候，指定了connectionTimeout、readTimeout、maxConnectionsPerHost、maxTotalConnections、connectionIdleTimeout參數。

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);
            }
            //......
        }

其中能夠看到maxConnectionsPerHost以及maxTotalConnections是配置在MonitoredConnectionManager；而connectionTimeout、readTimeout、connectionIdleTimeout則是配置在apache http client的HttpConnectionParams上。

參數配置

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());
    }

能夠看到這裏從EurekaClientConfig讀取，其映射關係以下：

屬性	配置	默認值	說明
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

小結

能夠經過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參數來配置及管理eureka client請求eureka server的http鏈接。

doc

• EurekaJerseyClientImpl