tillrohrmann commented on a change in pull request #13055: URL: https://github.com/apache/flink/pull/13055#discussion_r464889065
########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(1, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat("No results are expected, yet, since no leader was elected.", firstAddress, is(nullValue())); + + stopTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("No result is expected since there was no leader elected before stopping the server, yet.", secondAddress, is(nullValue())); + } + + @Test + public void testConnectionSuspendedHandling() throws Exception { + // initialize LeaderElection-related instances + String leaderAddress = "localhost"; + LeaderElectionService leaderElectionService = ZooKeeperUtils.createLeaderElectionService(zooKeeperClient, config); + TestingContender contender = new TestingContender(leaderAddress, leaderElectionService); + leaderElectionService.start(contender); + + // initialize LeaderRetrievalService Review comment: This is somewhat obvious. ########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/leaderretrieval/ZooKeeperLeaderRetrievalService.java ########## @@ -209,4 +211,15 @@ protected void handleStateChange(ConnectionState newState) { public void unhandledError(String s, Throwable throwable) { leaderListener.handleError(new FlinkException("Unhandled error in ZooKeeperLeaderRetrievalService:" + s, throwable)); } + + private void notifyLeaderLoss() { + if (lastLeaderAddress != null || lastLeaderSessionID != null) { + LOG.debug( + "No leader information could be retrieved. Any listeners will be notified."); + + lastLeaderAddress = null; + lastLeaderSessionID = null; + leaderListener.notifyLeaderAddress(null, null); + } + } Review comment: This method is duplicating logic which is already contained in `ZooKeeperLeaderRetrievalService.nodeChanged`. I would suggest to factor out a method `notifyIfNewLeaderAddress(String newLeaderAddress, UUID newLeaderSessionID)`. `notifyLeaderLoss` could call this method with `notifyIfNewLeaderAddress(null, null)`. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { Review comment: The class uses whitespaces for indentation. The Flink community uses tabs. Here is a pointer on how to set up your IDE to import Flink's checkstyle definition: https://ci.apache.org/projects/flink/flink-docs-stable/flinkDev/ide_setup.html. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(1, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat("No results are expected, yet, since no leader was elected.", firstAddress, is(nullValue())); + + stopTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("No result is expected since there was no leader elected before stopping the server, yet.", secondAddress, is(nullValue())); + } + + @Test + public void testConnectionSuspendedHandling() throws Exception { + // initialize LeaderElection-related instances + String leaderAddress = "localhost"; + LeaderElectionService leaderElectionService = ZooKeeperUtils.createLeaderElectionService(zooKeeperClient, config); + TestingContender contender = new TestingContender(leaderAddress, leaderElectionService); + leaderElectionService.start(contender); + + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(2, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // 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)); + + stopTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("The next result must not be missing.", secondAddress, not(is(nullValue()))); + assertThat("The next result is expected to be null.", secondAddress.get(), is(nullValue())); + } + + private void stopTestServer() throws IOException { + if (testingServer != null) { + testingServer.stop(); + testingServer = null; + } + } + + private static class QueueLeaderElectionListener implements LeaderRetrievalListener { + + private final BlockingQueue<CompletableFuture<String>> queue; + private final Duration timeout; + + public QueueLeaderElectionListener(int expectedCalls, Duration timeout) { + this.queue = new ArrayBlockingQueue<>(expectedCalls); + this.timeout = timeout; + } + + @Override + public void notifyLeaderAddress(String leaderAddress, UUID leaderSessionID) { + try { + this.queue.offer(CompletableFuture.completedFuture(leaderAddress), timeout.toMillis(), TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + throw new IllegalStateException(e); + } + } + + public CompletableFuture<String> next() { + try { + return this.queue.poll(timeout.toMillis(), TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + throw new IllegalStateException(e); + } + } + + @Override + public void handleError(Exception exception) { + // nothing to do Review comment: Let's throw the exception at least. Otherwise we might swallow it which could hide a problem and which makes debugging harder. ########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/leaderretrieval/ZooKeeperLeaderRetrievalService.java ########## @@ -209,4 +211,15 @@ protected void handleStateChange(ConnectionState newState) { public void unhandledError(String s, Throwable throwable) { leaderListener.handleError(new FlinkException("Unhandled error in ZooKeeperLeaderRetrievalService:" + s, throwable)); } + + private void notifyLeaderLoss() { + if (lastLeaderAddress != null || lastLeaderSessionID != null) { + LOG.debug( + "No leader information could be retrieved. Any listeners will be notified."); + + lastLeaderAddress = null; + lastLeaderSessionID = null; Review comment: The state changes are not happening under the `lock`. If you introduce `notifyIfNewLeaderAddress`, then this call should happen under the `lock` and we could add `@GuardedBy("lock")` to `notifyIfNewLeaderAddress` to state this contract. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(1, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat("No results are expected, yet, since no leader was elected.", firstAddress, is(nullValue())); + + stopTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("No result is expected since there was no leader elected before stopping the server, yet.", secondAddress, is(nullValue())); + } + + @Test + public void testConnectionSuspendedHandling() throws Exception { + // initialize LeaderElection-related instances Review comment: Somewhat obvious. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(1, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); + assertThat("No results are expected, yet, since no leader was elected.", firstAddress, is(nullValue())); + + stopTestServer(); + + CompletableFuture<String> secondAddress = queueLeaderElectionListener.next(); + assertThat("No result is expected since there was no leader elected before stopping the server, yet.", secondAddress, is(nullValue())); + } + + @Test + public void testConnectionSuspendedHandling() throws Exception { + // initialize LeaderElection-related instances + String leaderAddress = "localhost"; + LeaderElectionService leaderElectionService = ZooKeeperUtils.createLeaderElectionService(zooKeeperClient, config); + TestingContender contender = new TestingContender(leaderAddress, leaderElectionService); + leaderElectionService.start(contender); + + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(2, Duration.ofSeconds(1)); Review comment: A timeout of 1 second can be too low for slow testing machines. I would suggest to not use a timeout here since we are expecting that the future will be delivered. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService + QueueLeaderElectionListener queueLeaderElectionListener = new QueueLeaderElectionListener(1, Duration.ofSeconds(1)); + + ZooKeeperLeaderRetrievalService testInstance = ZooKeeperUtils.createLeaderRetrievalService(zooKeeperClient, config); + testInstance.start(queueLeaderElectionListener); + + // do the testing + CompletableFuture<String> firstAddress = queueLeaderElectionListener.next(); Review comment: This call adds a delay of 1s. Since we are calling it twice it adds 2s to the test duration. Since it is generally hard to test the absence of something I would suggest to decrease the timeout to 50 ms. ########## File path: flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java ########## @@ -0,0 +1,162 @@ +/* + * 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.configuration.Configuration; +import org.apache.flink.configuration.HighAvailabilityOptions; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener; +import org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService; +import org.apache.flink.runtime.util.ZooKeeperUtils; +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.Test; + +import java.io.IOException; +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.not; +import static org.hamcrest.CoreMatchers.nullValue; +import static org.junit.Assert.assertThat; + +/** + * Tests for the error handling in case of a suspended connection to the ZooKeeper instance. + */ +public class ZooKeeperLeaderElectionConnectionHandlingTest extends TestLogger { + + private TestingServer testingServer; + + private Configuration config; + + private CuratorFramework zooKeeperClient; + + @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); + } + + @After + public void after() throws Exception { + stopTestServer(); + + if (zooKeeperClient != null) { + zooKeeperClient.close(); + zooKeeperClient = null; + } + } + + @Test + public void testConnectionSuspendedHandlingDuringInitialization() throws Exception { + // initialize LeaderRetrievalService Review comment: Somewhat obvious. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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