tillrohrmann commented on a change in pull request #13055:
URL: https://github.com/apache/flink/pull/13055#discussion_r465074689
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/leaderretrieval/ZooKeeperLeaderRetrievalService.java
##########
@@ -192,15 +184,21 @@ protected void handleStateChange(ConnectionState
newState) {
LOG.debug("Connected to ZooKeeper quorum.
Leader retrieval can start.");
break;
case SUSPENDED:
- LOG.warn("Connection to ZooKeeper suspended.
Can no longer retrieve the leader from " +
- "ZooKeeper.");
+ synchronized (lock) {
+ LOG.warn("Connection to ZooKeeper
suspended. Can no longer retrieve the leader from " +
+ "ZooKeeper.");
Review comment:
Logging statements can happen outside of the `lock`.
##########
File path:
flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/ZooKeeperLeaderElectionConnectionHandlingTest.java
##########
@@ -0,0 +1,171 @@
+/*
+ * 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 {
+ QueueLeaderElectionListener queueLeaderElectionListener = new
QueueLeaderElectionListener(1, Duration.ofMillis(50));
+
+ 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 {
+ String leaderAddress = "localhost";
+ LeaderElectionService leaderElectionService =
ZooKeeperUtils.createLeaderElectionService(zooKeeperClient, config);
+ TestingContender contender = new
TestingContender(leaderAddress, leaderElectionService);
+ leaderElectionService.start(contender);
+
+ QueueLeaderElectionListener queueLeaderElectionListener = new
QueueLeaderElectionListener(2);
+
+ 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())));
Review comment:
```suggestion
assertThat("The next result must not be missing.",
secondAddress, is(not(nullValue())));
```
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/leaderretrieval/ZooKeeperLeaderRetrievalService.java
##########
@@ -192,15 +184,21 @@ protected void handleStateChange(ConnectionState
newState) {
LOG.debug("Connected to ZooKeeper quorum.
Leader retrieval can start.");
break;
case SUSPENDED:
- LOG.warn("Connection to ZooKeeper suspended.
Can no longer retrieve the leader from " +
- "ZooKeeper.");
+ synchronized (lock) {
+ LOG.warn("Connection to ZooKeeper
suspended. Can no longer retrieve the leader from " +
+ "ZooKeeper.");
+ notifyLeaderLoss();
+ }
break;
case RECONNECTED:
LOG.info("Connection to ZooKeeper was
reconnected. Leader retrieval can be restarted.");
break;
case LOST:
- LOG.warn("Connection to ZooKeeper lost. Can no
longer retrieve the leader from " +
- "ZooKeeper.");
+ synchronized (lock) {
+ LOG.warn("Connection to ZooKeeper lost.
Can no longer retrieve the leader from " +
+ "ZooKeeper.");
Review comment:
Same here.
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