Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 com.twitter.distributedlog.service; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Preconditions; import com.twitter.common.zookeeper.ServerSet; import com.twitter.distributedlog.client.ClientConfig; import com.twitter.distributedlog.client.DistributedLogClientImpl; import com.twitter.distributedlog.client.monitor.MonitorServiceClient; import com.twitter.distributedlog.client.resolver.RegionResolver; import com.twitter.distributedlog.client.resolver.DefaultRegionResolver; import com.twitter.distributedlog.client.routing.RegionsRoutingService; import com.twitter.distributedlog.client.routing.RoutingService; import com.twitter.distributedlog.client.routing.RoutingUtils; import com.twitter.finagle.builder.ClientBuilder; import com.twitter.finagle.stats.NullStatsReceiver; import com.twitter.finagle.stats.StatsReceiver; import com.twitter.finagle.thrift.ClientId; import org.apache.commons.lang.StringUtils; import java.net.SocketAddress; import java.net.URI; import java.util.Random; public final class DistributedLogClientBuilder { private static final Random random = new Random(System.currentTimeMillis()); private String _name = null; private ClientId _clientId = null; private RoutingService.Builder _routingServiceBuilder = null; private ClientBuilder _clientBuilder = null; private StatsReceiver _statsReceiver = new NullStatsReceiver(); private StatsReceiver _streamStatsReceiver = new NullStatsReceiver(); private ClientConfig _clientConfig = new ClientConfig(); private boolean _enableRegionStats = false; private final RegionResolver _regionResolver = new DefaultRegionResolver(); /** * Create a client builder * * @return client builder */ public static DistributedLogClientBuilder newBuilder() { return new DistributedLogClientBuilder(); } public static DistributedLogClientBuilder newBuilder(DistributedLogClientBuilder builder) { DistributedLogClientBuilder newBuilder = new DistributedLogClientBuilder(); newBuilder._name = builder._name; newBuilder._clientId = builder._clientId; newBuilder._clientBuilder = builder._clientBuilder; newBuilder._routingServiceBuilder = builder._routingServiceBuilder; newBuilder._statsReceiver = builder._statsReceiver; newBuilder._streamStatsReceiver = builder._streamStatsReceiver; newBuilder._enableRegionStats = builder._enableRegionStats; newBuilder._clientConfig = ClientConfig.newConfig(builder._clientConfig); return newBuilder; } // private constructor private DistributedLogClientBuilder() { } /** * Client Name. * * @param name * client name * @return client builder. */ public DistributedLogClientBuilder name(String name) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._name = name; return newBuilder; } /** * Client ID. * * @param clientId * client id * @return client builder. */ public DistributedLogClientBuilder clientId(ClientId clientId) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientId = clientId; return newBuilder; } /** * Serverset to access proxy services. * * @param serverSet * server set. * @return client builder. */ public DistributedLogClientBuilder serverSet(ServerSet serverSet) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._routingServiceBuilder = RoutingUtils.buildRoutingService(serverSet); newBuilder._enableRegionStats = false; return newBuilder; } /** * Server Sets to access proxy services. The <i>local</i> server set will be tried first, * then <i>remotes</i>. * * @param local local server set. * @param remotes remote server sets. * @return client builder. */ public DistributedLogClientBuilder serverSets(ServerSet local, ServerSet... remotes) { DistributedLogClientBuilder newBuilder = newBuilder(this); RoutingService.Builder[] builders = new RoutingService.Builder[remotes.length + 1]; builders[0] = RoutingUtils.buildRoutingService(local); for (int i = 1; i < builders.length; i++) { builders[i] = RoutingUtils.buildRoutingService(remotes[i - 1]); } newBuilder._routingServiceBuilder = RegionsRoutingService.newBuilder().resolver(_regionResolver) .routingServiceBuilders(builders); newBuilder._enableRegionStats = remotes.length > 0; return newBuilder; } /** * Name to access proxy services. * * @param finagleNameStr * finagle name string. * @return client builder. */ public DistributedLogClientBuilder finagleNameStr(String finagleNameStr) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._routingServiceBuilder = RoutingUtils.buildRoutingService(finagleNameStr); newBuilder._enableRegionStats = false; return newBuilder; } /** * Finagle name strs to access proxy services. The <i>local</i> finalge name str will be tried first, * then <i>remotes</i>. * * @param local local server set. * @param remotes remote server sets. * @return client builder. */ public DistributedLogClientBuilder finagleNameStrs(String local, String... remotes) { DistributedLogClientBuilder newBuilder = newBuilder(this); RoutingService.Builder[] builders = new RoutingService.Builder[remotes.length + 1]; builders[0] = RoutingUtils.buildRoutingService(local); for (int i = 1; i < builders.length; i++) { builders[i] = RoutingUtils.buildRoutingService(remotes[i - 1]); } newBuilder._routingServiceBuilder = RegionsRoutingService.newBuilder().routingServiceBuilders(builders) .resolver(_regionResolver); newBuilder._enableRegionStats = remotes.length > 0; return newBuilder; } /** * URI to access proxy services. Assuming the write proxies are announced under `.write_proxy` of * the provided namespace uri. * <p> * The builder will convert the dl uri (e.g. distributedlog://{zkserver}/path/to/namespace) to * zookeeper serverset based finagle name str (`zk!{zkserver}!/path/to/namespace/.write_proxy`) * * @param uri namespace uri to access the serverset of write proxies * @return distributedlog builder */ public DistributedLogClientBuilder uri(URI uri) { DistributedLogClientBuilder newBuilder = newBuilder(this); String zkServers = uri.getAuthority().replace(";", ","); String[] zkServerList = StringUtils.split(zkServers, ','); String finagleNameStr = String.format("zk!%s!%s/.write_proxy", zkServerList[random.nextInt(zkServerList.length)], // zk server uri.getPath()); newBuilder._routingServiceBuilder = RoutingUtils.buildRoutingService(finagleNameStr); newBuilder._enableRegionStats = false; return newBuilder; } /** * Address of write proxy to connect. * * @param address * write proxy address. * @return client builder. */ public DistributedLogClientBuilder host(SocketAddress address) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._routingServiceBuilder = RoutingUtils.buildRoutingService(address); newBuilder._enableRegionStats = false; return newBuilder; } private DistributedLogClientBuilder routingServiceBuilder(RoutingService.Builder builder) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._routingServiceBuilder = builder; newBuilder._enableRegionStats = false; return newBuilder; } /** * Routing Service to access proxy services. * * @param routingService * routing service * @return client builder. */ @VisibleForTesting public DistributedLogClientBuilder routingService(RoutingService routingService) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._routingServiceBuilder = RoutingUtils.buildRoutingService(routingService); newBuilder._enableRegionStats = false; return newBuilder; } /** * Stats receiver to expose client stats. * * @param statsReceiver * stats receiver. * @return client builder. */ public DistributedLogClientBuilder statsReceiver(StatsReceiver statsReceiver) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._statsReceiver = statsReceiver; return newBuilder; } /** * Stream Stats Receiver to expose per stream stats. * * @param streamStatsReceiver * stream stats receiver * @return client builder. */ public DistributedLogClientBuilder streamStatsReceiver(StatsReceiver streamStatsReceiver) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._streamStatsReceiver = streamStatsReceiver; return newBuilder; } /** * Set underlying finagle client builder. * * @param builder * finagle client builder. * @return client builder. */ public DistributedLogClientBuilder clientBuilder(ClientBuilder builder) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientBuilder = builder; return newBuilder; } /** * Backoff time when redirecting to an already retried host. * * @param ms * backoff time. * @return client builder. */ public DistributedLogClientBuilder redirectBackoffStartMs(int ms) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setRedirectBackoffStartMs(ms); return newBuilder; } /** * Max backoff time when redirecting to an already retried host. * * @param ms * backoff time. * @return client builder. */ public DistributedLogClientBuilder redirectBackoffMaxMs(int ms) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setRedirectBackoffMaxMs(ms); return newBuilder; } /** * Max redirects that is allowed per request. If <i>redirects</i> are * exhausted, fail the request immediately. * * @param redirects * max redirects allowed before failing a request. * @return client builder. */ public DistributedLogClientBuilder maxRedirects(int redirects) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setMaxRedirects(redirects); return newBuilder; } /** * Timeout per request in millis. * * @param timeoutMs * timeout per request in millis. * @return client builder. */ public DistributedLogClientBuilder requestTimeoutMs(int timeoutMs) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setRequestTimeoutMs(timeoutMs); return newBuilder; } /** * Set thriftmux enabled. * * @param enabled * is thriftmux enabled * @return client builder. */ public DistributedLogClientBuilder thriftmux(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setThriftMux(enabled); return newBuilder; } /** * Set failfast stream exception handling enabled. * * @param enabled * is failfast exception handling enabled * @return client builder. */ public DistributedLogClientBuilder streamFailfast(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setStreamFailfast(enabled); return newBuilder; } /** * Set the regex to match stream names that the client cares about. * * @param nameRegex * stream name regex * @return client builder */ public DistributedLogClientBuilder streamNameRegex(String nameRegex) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setStreamNameRegex(nameRegex); return newBuilder; } /** * Whether to use the new handshake endpoint to exchange ownership cache. Enable this * when the servers are updated to support handshaking with client info. * * @param enabled * new handshake endpoint is enabled. * @return client builder. */ public DistributedLogClientBuilder handshakeWithClientInfo(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setHandshakeWithClientInfo(enabled); return newBuilder; } /** * Set the periodic handshake interval in milliseconds. Every <code>intervalMs</code>, * the DL client will handshake with existing proxies again. If the interval is less than * ownership sync interval, the handshake won't sync ownerships. Otherwise, it will. * * @see #periodicOwnershipSyncIntervalMs(long) * @param intervalMs * handshake interval * @return client builder. */ public DistributedLogClientBuilder periodicHandshakeIntervalMs(long intervalMs) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setPeriodicHandshakeIntervalMs(intervalMs); return newBuilder; } /** * Set the periodic ownership sync interval in milliseconds. If periodic handshake is enabled, * the handshake will sync ownership if the elapsed time is larger than sync interval. * * @see #periodicHandshakeIntervalMs(long) * @param intervalMs * interval that handshake should sync ownerships. * @return client builder */ public DistributedLogClientBuilder periodicOwnershipSyncIntervalMs(long intervalMs) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setPeriodicOwnershipSyncIntervalMs(intervalMs); return newBuilder; } /** * Enable/Disable periodic dumping ownership cache. * * @param enabled * flag to enable/disable periodic dumping ownership cache * @return client builder. */ public DistributedLogClientBuilder periodicDumpOwnershipCache(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setPeriodicDumpOwnershipCacheEnabled(enabled); return newBuilder; } /** * Set periodic dumping ownership cache interval. * * @param intervalMs * interval on dumping ownership cache, in millis. * @return client builder */ public DistributedLogClientBuilder periodicDumpOwnershipCacheIntervalMs(long intervalMs) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setPeriodicDumpOwnershipCacheIntervalMs(intervalMs); return newBuilder; } /** * Enable handshake tracing. * * @param enabled * flag to enable/disable handshake tracing * @return client builder */ public DistributedLogClientBuilder handshakeTracing(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setHandshakeTracingEnabled(enabled); return newBuilder; } /** * Enable checksum on requests to the proxy. * * @param enabled * flag to enable/disable checksum * @return client builder */ public DistributedLogClientBuilder checksum(boolean enabled) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig.setChecksumEnabled(enabled); return newBuilder; } DistributedLogClientBuilder clientConfig(ClientConfig clientConfig) { DistributedLogClientBuilder newBuilder = newBuilder(this); newBuilder._clientConfig = ClientConfig.newConfig(clientConfig); return newBuilder; } /** * Build distributedlog client. * * @return distributedlog client. */ public DistributedLogClient build() { return buildClient(); } /** * Build monitor service client. * * @return monitor service client. */ public MonitorServiceClient buildMonitorClient() { return buildClient(); } DistributedLogClientImpl buildClient() { Preconditions.checkNotNull(_name, "No name provided."); Preconditions.checkNotNull(_clientId, "No client id provided."); Preconditions.checkNotNull(_routingServiceBuilder, "No routing service builder provided."); Preconditions.checkNotNull(_statsReceiver, "No stats receiver provided."); if (null == _streamStatsReceiver) { _streamStatsReceiver = new NullStatsReceiver(); } RoutingService routingService = _routingServiceBuilder.statsReceiver(_statsReceiver.scope("routing")) .build(); DistributedLogClientImpl clientImpl = new DistributedLogClientImpl(_name, _clientId, routingService, _clientBuilder, _clientConfig, _statsReceiver, _streamStatsReceiver, _regionResolver, _enableRegionStats); routingService.startService(); clientImpl.handshake(); return clientImpl; } }