| /* |
| * 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.pulsar.proxy.server; |
| |
| import static org.apache.bookkeeper.common.util.MathUtils.signSafeMod; |
| import io.netty.util.concurrent.DefaultThreadFactory; |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import org.apache.bookkeeper.common.annotation.InterfaceAudience; |
| import org.apache.bookkeeper.common.util.OrderedScheduler; |
| import org.apache.pulsar.broker.PulsarServerException; |
| import org.apache.pulsar.broker.resources.MetadataStoreCacheLoader; |
| import org.apache.pulsar.broker.resources.PulsarResources; |
| import org.apache.pulsar.common.classification.InterfaceStability; |
| import org.apache.pulsar.policies.data.loadbalancer.LoadManagerReport; |
| import org.apache.pulsar.policies.data.loadbalancer.ServiceLookupData; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Maintains available active broker list and returns next active broker in round-robin for discovery service. |
| * This is an API used by Proxy Extensions. |
| */ |
| @InterfaceStability.Evolving |
| @InterfaceAudience.LimitedPrivate |
| public class BrokerDiscoveryProvider implements Closeable { |
| |
| final MetadataStoreCacheLoader metadataStoreCacheLoader; |
| final PulsarResources pulsarResources; |
| |
| private final AtomicInteger counter = new AtomicInteger(); |
| |
| private final OrderedScheduler orderedExecutor = OrderedScheduler.newSchedulerBuilder().numThreads(4) |
| .name("pulsar-proxy-ordered").build(); |
| private final ScheduledExecutorService scheduledExecutorScheduler = Executors.newScheduledThreadPool(4, |
| new DefaultThreadFactory("pulsar-proxy-scheduled-executor")); |
| |
| public BrokerDiscoveryProvider(ProxyConfiguration config, PulsarResources pulsarResources) |
| throws PulsarServerException { |
| try { |
| this.pulsarResources = pulsarResources; |
| this.metadataStoreCacheLoader = new MetadataStoreCacheLoader(pulsarResources, |
| config.getMetadataStoreSessionTimeoutMillis()); |
| } catch (Exception e) { |
| LOG.error("Failed to start ZooKeeper {}", e.getMessage(), e); |
| throw new PulsarServerException("Failed to start zookeeper :" + e.getMessage(), e); |
| } |
| } |
| |
| /** |
| * Access the list of available brokers. |
| * Used by Protocol Handlers |
| * @return the list of available brokers |
| * @throws PulsarServerException |
| */ |
| public List<? extends ServiceLookupData> getAvailableBrokers() throws PulsarServerException { |
| return metadataStoreCacheLoader.getAvailableBrokers(); |
| } |
| |
| /** |
| * Find next broker {@link LoadManagerReport} in round-robin fashion. |
| * |
| * @return |
| * @throws PulsarServerException |
| */ |
| LoadManagerReport nextBroker() throws PulsarServerException { |
| List<LoadManagerReport> availableBrokers = metadataStoreCacheLoader.getAvailableBrokers(); |
| |
| if (availableBrokers.isEmpty()) { |
| throw new PulsarServerException("No active broker is available"); |
| } else { |
| int brokersCount = availableBrokers.size(); |
| int nextIdx = signSafeMod(counter.getAndIncrement(), brokersCount); |
| return availableBrokers.get(nextIdx); |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| metadataStoreCacheLoader.close(); |
| orderedExecutor.shutdown(); |
| scheduledExecutorScheduler.shutdownNow(); |
| } |
| |
| private static final Logger LOG = LoggerFactory.getLogger(BrokerDiscoveryProvider.class); |
| |
| } |