| /** |
| * 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.curator.framework.recipes.leader; |
| |
| import static org.junit.jupiter.api.Assertions.assertEquals; |
| import static org.junit.jupiter.api.Assertions.assertNotNull; |
| import com.google.common.collect.Lists; |
| import org.apache.curator.framework.CuratorFramework; |
| import org.apache.curator.framework.CuratorFrameworkFactory; |
| import org.apache.curator.retry.ExponentialBackoffRetry; |
| import org.apache.curator.test.InstanceSpec; |
| import org.apache.curator.test.TestingCluster; |
| import org.apache.curator.test.compatibility.CuratorTestBase; |
| import org.apache.curator.test.compatibility.Timing2; |
| import org.apache.curator.utils.CloseableUtils; |
| import org.junit.jupiter.api.Test; |
| |
| import java.util.Collection; |
| import java.util.List; |
| |
| public class TestLeaderLatchCluster extends CuratorTestBase |
| { |
| private static final int MAX_LOOPS = 5; |
| |
| private static class ClientAndLatch |
| { |
| final CuratorFramework client; |
| final LeaderLatch latch; |
| final int index; |
| |
| private ClientAndLatch(CuratorFramework client, LeaderLatch latch, int index) |
| { |
| this.client = client; |
| this.latch = latch; |
| this.index = index; |
| } |
| } |
| |
| @Test |
| public void testInCluster() throws Exception |
| { |
| final int PARTICIPANT_QTY = 3; |
| final int sessionLength = timing.session() / 4; |
| |
| List<ClientAndLatch> clients = Lists.newArrayList(); |
| TestingCluster cluster = createAndStartCluster(PARTICIPANT_QTY); |
| try |
| { |
| List<InstanceSpec> instances = Lists.newArrayList(cluster.getInstances()); |
| for ( int i = 0; i < PARTICIPANT_QTY; ++i ) |
| { |
| CuratorFramework client = CuratorFrameworkFactory.newClient(instances.get(i).getConnectString(), sessionLength, sessionLength, new ExponentialBackoffRetry(100, 3)); |
| LeaderLatch latch = new LeaderLatch(client, "/latch"); |
| |
| clients.add(new ClientAndLatch(client, latch, i)); |
| client.start(); |
| latch.start(); |
| } |
| |
| ClientAndLatch leader = waitForALeader(clients, timing); |
| assertNotNull(leader); |
| |
| cluster.killServer(instances.get(leader.index)); |
| |
| Thread.sleep(sessionLength * 2); |
| |
| leader = waitForALeader(clients, timing); |
| assertNotNull(leader); |
| |
| assertEquals(getLeaders(clients).size(), 1); |
| } |
| finally |
| { |
| for ( ClientAndLatch client : clients ) |
| { |
| CloseableUtils.closeQuietly(client.latch); |
| CloseableUtils.closeQuietly(client.client); |
| } |
| CloseableUtils.closeQuietly(cluster); |
| } |
| } |
| |
| @Override |
| protected void createServer() |
| { |
| // NOP |
| } |
| |
| private ClientAndLatch waitForALeader(List<ClientAndLatch> latches, Timing2 timing) throws InterruptedException |
| { |
| for ( int i = 0; i < MAX_LOOPS; ++i ) |
| { |
| List<ClientAndLatch> leaders = getLeaders(latches); |
| if ( leaders.size() != 0 ) |
| { |
| return leaders.get(0); |
| } |
| timing.sleepABit(); |
| } |
| return null; |
| } |
| |
| private List<ClientAndLatch> getLeaders(Collection<ClientAndLatch> latches) |
| { |
| List<ClientAndLatch> leaders = Lists.newArrayList(); |
| for ( ClientAndLatch clientAndLatch : latches ) |
| { |
| if ( clientAndLatch.latch.hasLeadership() ) |
| { |
| leaders.add(clientAndLatch); |
| } |
| } |
| return leaders; |
| } |
| } |