public class LeaderChangeStateCleanupTest extends TestLogger {
private static FiniteDuration timeout = TestingUtils.TESTING_DURATION();
private int numJMs = 2;
private int numTMs = 2;
private int numSlotsPerTM = 2;
private int parallelism = numTMs * numSlotsPerTM;
private Configuration configuration;
private LeaderElectionRetrievalTestingCluster cluster = null;
private JobGraph job = createBlockingJob(parallelism);
@Before
public void before() throws Exception {
Tasks.BlockingOnceReceiver$.MODULE$.blocking_$eq(true);
configuration = new Configuration();
configuration.setInteger(ConfigConstants.LOCAL_NUMBER_JOB_MANAGER, numJMs);
configuration.setInteger(ConfigConstants.LOCAL_NUMBER_TASK_MANAGER, numTMs);
configuration.setInteger(ConfigConstants.TASK_MANAGER_NUM_TASK_SLOTS, numSlotsPerTM);
cluster =
new LeaderElectionRetrievalTestingCluster(
configuration, true, false, StreamingMode.BATCH_ONLY);
cluster.start(false); // TaskManagers don't have to register at the JobManager
cluster.waitForActorsToBeAlive(); // we only wait until all actors are alive
}
@After
public void after() {
if (cluster != null) {
cluster.stop();
}
}
/**
* Tests that a job is properly canceled in the case of a leader change. In such an event all
* TaskManagers have to disconnect from the previous leader and connect to the newly elected
* leader.
*/
@Test
public void testStateCleanupAfterNewLeaderElectionAndListenerNotification() throws Exception {
UUID leaderSessionID1 = UUID.randomUUID();
UUID leaderSessionID2 = UUID.randomUUID();
// first make JM(0) the leader
cluster.grantLeadership(0, leaderSessionID1);
// notify all listeners
cluster.notifyRetrievalListeners(0, leaderSessionID1);
cluster.waitForTaskManagersToBeRegistered();
// submit blocking job so that it is not finished when we cancel it
cluster.submitJobDetached(job);
ActorGateway jm = cluster.getLeaderGateway(timeout);
Future<Object> wait =
jm.ask(new WaitForAllVerticesToBeRunningOrFinished(job.getJobID()), timeout);
Await.ready(wait, timeout);
Future<Object> jobRemoval = jm.ask(new NotifyWhenJobRemoved(job.getJobID()), timeout);
// make the JM(1) the new leader
cluster.grantLeadership(1, leaderSessionID2);
// notify all listeners about the event
cluster.notifyRetrievalListeners(1, leaderSessionID2);
Await.ready(jobRemoval, timeout);
cluster.waitForTaskManagersToBeRegistered();
ActorGateway jm2 = cluster.getLeaderGateway(timeout);
Future<Object> futureNumberSlots =
jm2.ask(JobManagerMessages.getRequestTotalNumberOfSlots(), timeout);
// check that all TMs have registered at the new leader
int numberSlots = (Integer) Await.result(futureNumberSlots, timeout);
assertEquals(parallelism, numberSlots);
// try to resubmit now the non-blocking job, it should complete successfully
Tasks.BlockingOnceReceiver$.MODULE$.blocking_$eq(false);
cluster.submitJobAndWait(job, false, timeout);
}
/**
* Tests that a job is properly canceled in the case of a leader change. However, this time only
* the JMs are notified about the leader change and the TMs still believe the old leader to have
* leadership.
*/
@Test
public void testStateCleanupAfterNewLeaderElection() throws Exception {
UUID leaderSessionID = UUID.randomUUID();
UUID newLeaderSessionID = UUID.randomUUID();
cluster.grantLeadership(0, leaderSessionID);
cluster.notifyRetrievalListeners(0, leaderSessionID);
cluster.waitForTaskManagersToBeRegistered();
// submit blocking job so that we can test job clean up
cluster.submitJobDetached(job);
ActorGateway jm = cluster.getLeaderGateway(timeout);
Future<Object> wait =
jm.ask(new WaitForAllVerticesToBeRunningOrFinished(job.getJobID()), timeout);
Await.ready(wait, timeout);
Future<Object> jobRemoval = jm.ask(new NotifyWhenJobRemoved(job.getJobID()), timeout);
// only notify the JMs about the new leader JM(1)
cluster.grantLeadership(1, newLeaderSessionID);
// job should be removed anyway
Await.ready(jobRemoval, timeout);
}
/**
* Tests that a job is properly canceled in the event of a leader change. However, this time only
* the TMs are notified about the changing leader. This should be enough to cancel the currently
* running job, though.
*/
@Test
public void testStateCleanupAfterListenerNotification() throws Exception {
UUID leaderSessionID = UUID.randomUUID();
UUID newLeaderSessionID = UUID.randomUUID();
cluster.grantLeadership(0, leaderSessionID);
cluster.notifyRetrievalListeners(0, leaderSessionID);
cluster.waitForTaskManagersToBeRegistered();
// submit blocking job
cluster.submitJobDetached(job);
ActorGateway jm = cluster.getLeaderGateway(timeout);
Future<Object> wait =
jm.ask(new WaitForAllVerticesToBeRunningOrFinished(job.getJobID()), timeout);
Await.ready(wait, timeout);
Future<Object> jobRemoval = jm.ask(new NotifyWhenJobRemoved(job.getJobID()), timeout);
// notify listeners (TMs) about the leader change
cluster.notifyRetrievalListeners(1, newLeaderSessionID);
Await.ready(jobRemoval, timeout);
}
/**
* Tests that the same JobManager can be reelected as the leader. Even though, the same JM is
* elected as the next leader, all currently running jobs should be canceled properly and all TMs
* should disconnect from the leader and then reconnect to it.
*/
@Test
public void testReelectionOfSameJobManager() throws Exception {
UUID leaderSessionID = UUID.randomUUID();
UUID newLeaderSessionID = UUID.randomUUID();
FiniteDuration shortTimeout = new FiniteDuration(20, TimeUnit.SECONDS);
cluster.grantLeadership(0, leaderSessionID);
cluster.notifyRetrievalListeners(0, leaderSessionID);
cluster.waitForTaskManagersToBeRegistered();
// submit blocking job
cluster.submitJobDetached(job);
ActorGateway jm = cluster.getLeaderGateway(timeout);
Future<Object> wait =
jm.ask(new WaitForAllVerticesToBeRunningOrFinished(job.getJobID()), timeout);
Await.ready(wait, timeout);
Future<Object> jobRemoval = jm.ask(new NotifyWhenJobRemoved(job.getJobID()), timeout);
// make JM(0) again the leader --> this implies first a leadership revokal
cluster.grantLeadership(0, newLeaderSessionID);
Await.ready(jobRemoval, timeout);
// The TMs should not be able to reconnect since they don't know the current leader
// session ID
try {
cluster.waitForTaskManagersToBeRegistered(shortTimeout);
fail("TaskManager should not be able to register at JobManager.");
} catch (TimeoutException e) {
// expected exception since the TMs have still the old leader session ID
}
// notify the TMs about the new (old) leader
cluster.notifyRetrievalListeners(0, newLeaderSessionID);
cluster.waitForTaskManagersToBeRegistered();
// try to resubmit now the non-blocking job, it should complete successfully
Tasks.BlockingOnceReceiver$.MODULE$.blocking_$eq(false);
cluster.submitJobAndWait(job, false, timeout);
}
public JobGraph createBlockingJob(int parallelism) {
Tasks.BlockingOnceReceiver$.MODULE$.blocking_$eq(true);
JobVertex sender = new JobVertex("sender");
JobVertex receiver = new JobVertex("receiver");
sender.setInvokableClass(Tasks.Sender.class);
receiver.setInvokableClass(Tasks.BlockingOnceReceiver.class);
sender.setParallelism(parallelism);
receiver.setParallelism(parallelism);
receiver.connectNewDataSetAsInput(sender, DistributionPattern.POINTWISE);
SlotSharingGroup slotSharingGroup = new SlotSharingGroup();
sender.setSlotSharingGroup(slotSharingGroup);
receiver.setSlotSharingGroup(slotSharingGroup);
return new JobGraph("Blocking test job", sender, receiver);
}
}
private void submitJobGraphAndWait(final JobGraph jobGraph) throws JobExecutionException {
flink.submitJobAndWait(jobGraph, false, TestingUtils.TESTING_DURATION());
}
