nicoweidner commented on a change in pull request #16801: URL: https://github.com/apache/flink/pull/16801#discussion_r688590842
########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderRetrievalConnectionHandlingTest.java ########## @@ -0,0 +1,390 @@ +/* + * 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.flink.runtime.leaderelection; + +import org.apache.flink.api.common.time.Deadline; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalDriver; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalEventHandler; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalDriver; +import org.apache.flink.runtime.testutils.CommonTestUtils; +import org.apache.flink.runtime.util.TestingFatalErrorHandlerResource; +import org.apache.flink.runtime.util.ZooKeeperUtils; +import org.apache.flink.util.Preconditions; +import org.apache.flink.util.TestLogger; + +import org.apache.flink.shaded.curator4.org.apache.curator.framework.CuratorFramework; + +import org.apache.curator.test.TestingServer; +import org.junit.After; +import org.junit.Before; +import org.junit.Rule; +import org.junit.Test; + +import javax.annotation.Nullable; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.ObjectOutputStream; +import java.time.Duration; +import java.util.UUID; +import java.util.concurrent.ArrayBlockingQueue; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.TimeUnit; + +import static org.hamcrest.CoreMatchers.is; +import static org.hamcrest.CoreMatchers.notNullValue; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.hamcrest.MatcherAssert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance when + * retrieving the leader information. + */ +public class ZooKeeperLeaderRetrievalConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @Rule + public final TestingFatalErrorHandlerResource fatalErrorHandlerResource = + new TestingFatalErrorHandlerResource(); + + @Before + public void before() throws Exception { + testingServer = new TestingServer(); + + config = new Configuration(); + config.setString(HighAvailabilityOptions.HA_MODE, "zookeeper"); + config.setString( + HighAvailabilityOptions.HA_ZOOKEEPER_QUORUM, testingServer.getConnectString()); + + zooKeeperClient = ZooKeeperUtils.startCuratorFramework(config); + zooKeeperClient.blockUntilConnected(); + } + + @After + public void after() throws Exception { + closeTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + final QueueLeaderElectionListener queueLeaderElectionListener = + new QueueLeaderElectionListener(1); + + LeaderRetrievalDriver leaderRetrievalDriver = null; + try { + leaderRetrievalDriver = + ZooKeeperUtils.createLeaderRetrievalDriverFactory(zooKeeperClient) + .createLeaderRetrievalDriver( + queueLeaderElectionListener, + fatalErrorHandlerResource.getFatalErrorHandler()); + + // do the testing + final CompletableFuture<String> firstAddress = + queueLeaderElectionListener.next(Duration.ofMillis(50)); + assertThat( + "No results are expected, yet, since no leader was elected.", + firstAddress, + is(nullValue())); + + closeTestServer(); + + // QueueLeaderElectionListener will be notified with an empty leader when ZK connection + // is suspended + final CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("The next result must not be missing.", secondAddress, is(notNullValue())); + assertThat( + "The next result is expected to be null.", + secondAddress.get(), + is(nullValue())); + } finally { + if (leaderRetrievalDriver != null) { + leaderRetrievalDriver.close(); + } + } + } + + @Test + public void testConnectionSuspendedHandling() throws Exception { + final String retrievalPath = "/testConnectionSuspendedHandling"; + final String leaderAddress = "localhost"; + + final QueueLeaderElectionListener queueLeaderElectionListener = + new QueueLeaderElectionListener(1); + ZooKeeperLeaderRetrievalDriver leaderRetrievalDriver = null; + try { + leaderRetrievalDriver = + new ZooKeeperLeaderRetrievalDriver( + zooKeeperClient, + retrievalPath, + queueLeaderElectionListener, + ZooKeeperLeaderRetrievalDriver.LeaderInformationClearancePolicy + .ON_SUSPENDED_CONNECTION, + fatalErrorHandlerResource.getFatalErrorHandler()); + + writeLeaderInformationToZooKeeper( + leaderRetrievalDriver.getConnectionInformationPath(), + leaderAddress, + UUID.randomUUID()); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat( + "The first result is expected to be the initially set leader address.", + firstAddress.get(), + is(leaderAddress)); + + closeTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("The next result must not be missing.", secondAddress, is(notNullValue())); + assertThat( + "The next result is expected to be null.", + secondAddress.get(), + is(nullValue())); + } finally { + if (leaderRetrievalDriver != null) { + leaderRetrievalDriver.close(); + } + } + } + + @Test + public void testSuspendedConnectionDoesNotClearLeaderInformationIfClearanceOnLostConnection() + throws Exception { + final String retrievalPath = "/testConnectionSuspendedHandling"; + final String leaderAddress = "localhost"; + + final QueueLeaderElectionListener queueLeaderElectionListener = + new QueueLeaderElectionListener(1); + ZooKeeperLeaderRetrievalDriver leaderRetrievalDriver = null; + try { + leaderRetrievalDriver = + new ZooKeeperLeaderRetrievalDriver( + zooKeeperClient, + retrievalPath, + queueLeaderElectionListener, + ZooKeeperLeaderRetrievalDriver.LeaderInformationClearancePolicy + .ON_LOST_CONNECTION, + fatalErrorHandlerResource.getFatalErrorHandler()); + + writeLeaderInformationToZooKeeper( + leaderRetrievalDriver.getConnectionInformationPath(), + leaderAddress, + UUID.randomUUID()); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat( + "The first result is expected to be the initially set leader address.", + firstAddress.get(), + is(leaderAddress)); + + closeTestServer(); Review comment: Ah, I did not check exactly which code was old. I assumed this part was at least modified. It's fine either way! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
