| /** |
| * 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 org.apache.distributedlog.client.routing; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.collect.Sets; |
| import org.apache.distributedlog.client.resolver.RegionResolver; |
| import com.twitter.finagle.NoBrokersAvailableException; |
| import com.twitter.finagle.stats.NullStatsReceiver; |
| import com.twitter.finagle.stats.StatsReceiver; |
| import java.net.SocketAddress; |
| import java.util.Set; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Chain multiple routing services. |
| */ |
| public class RegionsRoutingService implements RoutingService { |
| |
| private static final Logger logger = LoggerFactory.getLogger(RegionsRoutingService.class); |
| |
| /** |
| * Create a multiple regions routing services based on a list of region routing {@code services}. |
| * |
| * <p>It is deprecated. Please use {@link Builder} to build multiple regions routing service. |
| * |
| * @param regionResolver region resolver |
| * @param services a list of region routing services. |
| * @return multiple regions routing service |
| * @see Builder |
| */ |
| @Deprecated |
| public static RegionsRoutingService of(RegionResolver regionResolver, |
| RoutingService...services) { |
| return new RegionsRoutingService(regionResolver, services); |
| } |
| |
| /** |
| * Create a builder to build a multiple-regions routing service. |
| * |
| * @return builder to build a multiple-regions routing service. |
| */ |
| public static Builder newBuilder() { |
| return new Builder(); |
| } |
| |
| /** |
| * Builder to build a multiple-regions routing service. |
| */ |
| public static class Builder implements RoutingService.Builder { |
| |
| private RegionResolver resolver; |
| private RoutingService.Builder[] routingServiceBuilders; |
| private StatsReceiver statsReceiver = NullStatsReceiver.get(); |
| |
| private Builder() {} |
| |
| public Builder routingServiceBuilders(RoutingService.Builder...builders) { |
| this.routingServiceBuilders = builders; |
| return this; |
| } |
| |
| public Builder resolver(RegionResolver regionResolver) { |
| this.resolver = regionResolver; |
| return this; |
| } |
| |
| @Override |
| public RoutingService.Builder statsReceiver(StatsReceiver statsReceiver) { |
| this.statsReceiver = statsReceiver; |
| return this; |
| } |
| |
| @Override |
| public RegionsRoutingService build() { |
| checkNotNull(routingServiceBuilders, "No routing service builder provided."); |
| checkNotNull(resolver, "No region resolver provided."); |
| checkNotNull(statsReceiver, "No stats receiver provided"); |
| RoutingService[] services = new RoutingService[routingServiceBuilders.length]; |
| for (int i = 0; i < services.length; i++) { |
| String statsScope; |
| if (0 == i) { |
| statsScope = "local"; |
| } else { |
| statsScope = "remote_" + i; |
| } |
| services[i] = routingServiceBuilders[i] |
| .statsReceiver(statsReceiver.scope(statsScope)) |
| .build(); |
| } |
| return new RegionsRoutingService(resolver, services); |
| } |
| } |
| |
| protected final RegionResolver regionResolver; |
| protected final RoutingService[] routingServices; |
| |
| private RegionsRoutingService(RegionResolver resolver, |
| RoutingService[] routingServices) { |
| this.regionResolver = resolver; |
| this.routingServices = routingServices; |
| } |
| |
| @Override |
| public Set<SocketAddress> getHosts() { |
| Set<SocketAddress> hosts = Sets.newHashSet(); |
| for (RoutingService rs : routingServices) { |
| hosts.addAll(rs.getHosts()); |
| } |
| return hosts; |
| } |
| |
| @Override |
| public void startService() { |
| for (RoutingService service : routingServices) { |
| service.startService(); |
| } |
| logger.info("Regions Routing Service Started"); |
| } |
| |
| @Override |
| public void stopService() { |
| for (RoutingService service : routingServices) { |
| service.stopService(); |
| } |
| logger.info("Regions Routing Service Stopped"); |
| } |
| |
| @Override |
| public RoutingService registerListener(RoutingListener listener) { |
| for (RoutingService service : routingServices) { |
| service.registerListener(listener); |
| } |
| return this; |
| } |
| |
| @Override |
| public RoutingService unregisterListener(RoutingListener listener) { |
| for (RoutingService service : routingServices) { |
| service.registerListener(listener); |
| } |
| return this; |
| } |
| |
| @Override |
| public SocketAddress getHost(String key, RoutingContext routingContext) |
| throws NoBrokersAvailableException { |
| for (RoutingService service : routingServices) { |
| try { |
| SocketAddress addr = service.getHost(key, routingContext); |
| if (routingContext.hasUnavailableRegions()) { |
| // current region is unavailable |
| String region = regionResolver.resolveRegion(addr); |
| if (routingContext.isUnavailableRegion(region)) { |
| continue; |
| } |
| } |
| if (!routingContext.isTriedHost(addr)) { |
| return addr; |
| } |
| } catch (NoBrokersAvailableException nbae) { |
| // if there isn't broker available in current service, try next service. |
| logger.debug("No brokers available in region {} : ", service, nbae); |
| } |
| } |
| throw new NoBrokersAvailableException("No host found for " + key + ", routing context : " + routingContext); |
| } |
| |
| @Override |
| public void removeHost(SocketAddress address, Throwable reason) { |
| for (RoutingService service : routingServices) { |
| service.removeHost(address, reason); |
| } |
| } |
| } |