kafka ConsumerCoordinator 源码
kafka ConsumerCoordinator 代码
文件路径：/clients/src/main/java/org/apache/kafka/clients/consumer/internals/ConsumerCoordinator.java
/*
* 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.kafka.clients.consumer.internals;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.kafka.clients.GroupRebalanceConfig;
import org.apache.kafka.clients.consumer.CommitFailedException;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerGroupMetadata;
import org.apache.kafka.clients.consumer.ConsumerPartitionAssignor;
import org.apache.kafka.clients.consumer.ConsumerPartitionAssignor.Assignment;
import org.apache.kafka.clients.consumer.ConsumerPartitionAssignor.GroupSubscription;
import org.apache.kafka.clients.consumer.ConsumerPartitionAssignor.RebalanceProtocol;
import org.apache.kafka.clients.consumer.ConsumerPartitionAssignor.Subscription;
import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
import org.apache.kafka.clients.consumer.OffsetAndMetadata;
import org.apache.kafka.clients.consumer.OffsetCommitCallback;
import org.apache.kafka.clients.consumer.RetriableCommitFailedException;
import org.apache.kafka.clients.consumer.internals.Utils.TopicPartitionComparator;
import org.apache.kafka.common.Cluster;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.Node;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.errors.FencedInstanceIdException;
import org.apache.kafka.common.errors.GroupAuthorizationException;
import org.apache.kafka.common.errors.InterruptException;
import org.apache.kafka.common.errors.UnstableOffsetCommitException;
import org.apache.kafka.common.errors.RebalanceInProgressException;
import org.apache.kafka.common.errors.RetriableException;
import org.apache.kafka.common.errors.TimeoutException;
import org.apache.kafka.common.errors.TopicAuthorizationException;
import org.apache.kafka.common.errors.WakeupException;
import org.apache.kafka.common.message.JoinGroupRequestData;
import org.apache.kafka.common.message.JoinGroupResponseData;
import org.apache.kafka.common.message.OffsetCommitRequestData;
import org.apache.kafka.common.message.OffsetCommitResponseData;
import org.apache.kafka.common.metrics.Measurable;
import org.apache.kafka.common.metrics.Metrics;
import org.apache.kafka.common.metrics.Sensor;
import org.apache.kafka.common.metrics.stats.Avg;
import org.apache.kafka.common.metrics.stats.Max;
import org.apache.kafka.common.protocol.ApiKeys;
import org.apache.kafka.common.protocol.Errors;
import org.apache.kafka.common.record.RecordBatch;
import org.apache.kafka.common.requests.JoinGroupRequest;
import org.apache.kafka.common.requests.OffsetCommitRequest;
import org.apache.kafka.common.requests.OffsetCommitResponse;
import org.apache.kafka.common.requests.OffsetFetchRequest;
import org.apache.kafka.common.requests.OffsetFetchResponse;
import org.apache.kafka.common.utils.LogContext;
import org.apache.kafka.common.utils.Time;
import org.apache.kafka.common.utils.Timer;
import org.apache.kafka.common.utils.Utils;
import org.slf4j.Logger;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import java.util.stream.Collectors;
import static org.apache.kafka.clients.consumer.ConsumerConfig.ASSIGN_FROM_SUBSCRIBED_ASSIGNORS;
import static org.apache.kafka.clients.consumer.CooperativeStickyAssignor.COOPERATIVE_STICKY_ASSIGNOR_NAME;
/**
* This class manages the coordination process with the consumer coordinator.
*/
public final class ConsumerCoordinator extends AbstractCoordinator {
private final static TopicPartitionComparator COMPARATOR = new TopicPartitionComparator();
private final GroupRebalanceConfig rebalanceConfig;
private final Logger log;
private final List<ConsumerPartitionAssignor> assignors;
private final ConsumerMetadata metadata;
private final ConsumerCoordinatorMetrics sensors;
private final SubscriptionState subscriptions;
private final OffsetCommitCallback defaultOffsetCommitCallback;
private final boolean autoCommitEnabled;
private final int autoCommitIntervalMs;
private final ConsumerInterceptors<?, ?> interceptors;
private final AtomicInteger pendingAsyncCommits;
// this collection must be thread-safe because it is modified from the response handler
// of offset commit requests, which may be invoked from the heartbeat thread
private final ConcurrentLinkedQueue<OffsetCommitCompletion> completedOffsetCommits;
private boolean isLeader = false;
private Set<String> joinedSubscription;
private MetadataSnapshot metadataSnapshot;
private MetadataSnapshot assignmentSnapshot;
private Timer nextAutoCommitTimer;
private AtomicBoolean asyncCommitFenced;
private ConsumerGroupMetadata groupMetadata;
private final boolean throwOnFetchStableOffsetsUnsupported;
// hold onto request&future for committed offset requests to enable async calls.
private PendingCommittedOffsetRequest pendingCommittedOffsetRequest = null;
private static class PendingCommittedOffsetRequest {
private final Set<TopicPartition> requestedPartitions;
private final Generation requestedGeneration;
private final RequestFuture<Map<TopicPartition, OffsetAndMetadata>> response;
private PendingCommittedOffsetRequest(final Set<TopicPartition> requestedPartitions,
final Generation generationAtRequestTime,
final RequestFuture<Map<TopicPartition, OffsetAndMetadata>> response) {
this.requestedPartitions = Objects.requireNonNull(requestedPartitions);
this.response = Objects.requireNonNull(response);
this.requestedGeneration = generationAtRequestTime;
}
private boolean sameRequest(final Set<TopicPartition> currentRequest, final Generation currentGeneration) {
return Objects.equals(requestedGeneration, currentGeneration) && requestedPartitions.equals(currentRequest);
}
}
private final RebalanceProtocol protocol;
// pending commit offset request in onJoinPrepare
private RequestFuture<Void> autoCommitOffsetRequestFuture = null;
// a timer for join prepare to know when to stop.
// it'll set to rebalance timeout so that the member can join the group successfully
// even though offset commit failed.
private Timer joinPrepareTimer = null;
/**
* Initialize the coordination manager.
*/
public ConsumerCoordinator(GroupRebalanceConfig rebalanceConfig,
LogContext logContext,
ConsumerNetworkClient client,
List<ConsumerPartitionAssignor> assignors,
ConsumerMetadata metadata,
SubscriptionState subscriptions,
Metrics metrics,
String metricGrpPrefix,
Time time,
boolean autoCommitEnabled,
int autoCommitIntervalMs,
ConsumerInterceptors<?, ?> interceptors,
boolean throwOnFetchStableOffsetsUnsupported) {
super(rebalanceConfig,
logContext,
client,
metrics,
metricGrpPrefix,
time);
this.rebalanceConfig = rebalanceConfig;
this.log = logContext.logger(ConsumerCoordinator.class);
this.metadata = metadata;
this.metadataSnapshot = new MetadataSnapshot(subscriptions, metadata.fetch(), metadata.updateVersion());
this.subscriptions = subscriptions;
this.defaultOffsetCommitCallback = new DefaultOffsetCommitCallback();
this.autoCommitEnabled = autoCommitEnabled;
this.autoCommitIntervalMs = autoCommitIntervalMs;
this.assignors = assignors;
this.completedOffsetCommits = new ConcurrentLinkedQueue<>();
this.sensors = new ConsumerCoordinatorMetrics(metrics, metricGrpPrefix);
this.interceptors = interceptors;
this.pendingAsyncCommits = new AtomicInteger();
this.asyncCommitFenced = new AtomicBoolean(false);
this.groupMetadata = new ConsumerGroupMetadata(rebalanceConfig.groupId,
JoinGroupRequest.UNKNOWN_GENERATION_ID, JoinGroupRequest.UNKNOWN_MEMBER_ID, rebalanceConfig.groupInstanceId);
this.throwOnFetchStableOffsetsUnsupported = throwOnFetchStableOffsetsUnsupported;
if (autoCommitEnabled)
this.nextAutoCommitTimer = time.timer(autoCommitIntervalMs);
// select the rebalance protocol such that:
// 1. only consider protocols that are supported by all the assignors. If there is no common protocols supported
// across all the assignors, throw an exception.
// 2. if there are multiple protocols that are commonly supported, select the one with the highest id (i.e. the
// id number indicates how advanced the protocol is).
// we know there are at least one assignor in the list, no need to double check for NPE
if (!assignors.isEmpty()) {
List<RebalanceProtocol> supportedProtocols = new ArrayList<>(assignors.get(0).supportedProtocols());
for (ConsumerPartitionAssignor assignor : assignors) {
supportedProtocols.retainAll(assignor.supportedProtocols());
}
if (supportedProtocols.isEmpty()) {
throw new IllegalArgumentException("Specified assignors " +
assignors.stream().map(ConsumerPartitionAssignor::name).collect(Collectors.toSet()) +
" do not have commonly supported rebalance protocol");
}
Collections.sort(supportedProtocols);
protocol = supportedProtocols.get(supportedProtocols.size() - 1);
} else {
protocol = null;
}
this.metadata.requestUpdate();
}
// package private for testing
boolean isLeader() {
return this.isLeader;
}
// package private for testing
SubscriptionState subscriptionState() {
return this.subscriptions;
}
@Override
public String protocolType() {
return ConsumerProtocol.PROTOCOL_TYPE;
}
@Override
protected JoinGroupRequestData.JoinGroupRequestProtocolCollection metadata() {
log.debug("Joining group with current subscription: {}", subscriptions.subscription());
this.joinedSubscription = subscriptions.subscription();
JoinGroupRequestData.JoinGroupRequestProtocolCollection protocolSet = new JoinGroupRequestData.JoinGroupRequestProtocolCollection();
List<String> topics = new ArrayList<>(joinedSubscription);
for (ConsumerPartitionAssignor assignor : assignors) {
Subscription subscription = new Subscription(topics,
assignor.subscriptionUserData(joinedSubscription),
subscriptions.assignedPartitionsList());
ByteBuffer metadata = ConsumerProtocol.serializeSubscription(subscription);
protocolSet.add(new JoinGroupRequestData.JoinGroupRequestProtocol()
.setName(assignor.name())
.setMetadata(Utils.toArray(metadata)));
}
return protocolSet;
}
public void updatePatternSubscription(Cluster cluster) {
final Set<String> topicsToSubscribe = cluster.topics().stream()
.filter(subscriptions::matchesSubscribedPattern)
.collect(Collectors.toSet());
if (subscriptions.subscribeFromPattern(topicsToSubscribe))
metadata.requestUpdateForNewTopics();
}
private ConsumerPartitionAssignor lookupAssignor(String name) {
for (ConsumerPartitionAssignor assignor : this.assignors) {
if (assignor.name().equals(name))
return assignor;
}
return null;
}
private void maybeUpdateJoinedSubscription(Set<TopicPartition> assignedPartitions) {
if (subscriptions.hasPatternSubscription()) {
// Check if the assignment contains some topics that were not in the original
// subscription, if yes we will obey what leader has decided and add these topics
// into the subscriptions as long as they still match the subscribed pattern
Set<String> addedTopics = new HashSet<>();
// this is a copy because its handed to listener below
for (TopicPartition tp : assignedPartitions) {
if (!joinedSubscription.contains(tp.topic()))
addedTopics.add(tp.topic());
}
if (!addedTopics.isEmpty()) {
Set<String> newSubscription = new HashSet<>(subscriptions.subscription());
Set<String> newJoinedSubscription = new HashSet<>(joinedSubscription);
newSubscription.addAll(addedTopics);
newJoinedSubscription.addAll(addedTopics);
if (this.subscriptions.subscribeFromPattern(newSubscription))
metadata.requestUpdateForNewTopics();
this.joinedSubscription = newJoinedSubscription;
}
}
}
private Exception invokeOnAssignment(final ConsumerPartitionAssignor assignor, final Assignment assignment) {
log.info("Notifying assignor about the new {}", assignment);
try {
assignor.onAssignment(assignment, groupMetadata);
} catch (Exception e) {
return e;
}
return null;
}
private Exception invokePartitionsAssigned(final SortedSet<TopicPartition> assignedPartitions) {
log.info("Adding newly assigned partitions: {}", Utils.join(assignedPartitions, ", "));
ConsumerRebalanceListener listener = subscriptions.rebalanceListener();
try {
final long startMs = time.milliseconds();
listener.onPartitionsAssigned(assignedPartitions);
sensors.assignCallbackSensor.record(time.milliseconds() - startMs);
} catch (WakeupException | InterruptException e) {
throw e;
} catch (Exception e) {
log.error("User provided listener {} failed on invocation of onPartitionsAssigned for partitions {}",
listener.getClass().getName(), assignedPartitions, e);
return e;
}
return null;
}
private Exception invokePartitionsRevoked(final SortedSet<TopicPartition> revokedPartitions) {
log.info("Revoke previously assigned partitions {}", Utils.join(revokedPartitions, ", "));
Set<TopicPartition> revokePausedPartitions = subscriptions.pausedPartitions();
revokePausedPartitions.retainAll(revokedPartitions);
if (!revokePausedPartitions.isEmpty())
log.info("The pause flag in partitions [{}] will be removed due to revocation.", Utils.join(revokePausedPartitions, ", "));
ConsumerRebalanceListener listener = subscriptions.rebalanceListener();
try {
final long startMs = time.milliseconds();
listener.onPartitionsRevoked(revokedPartitions);
sensors.revokeCallbackSensor.record(time.milliseconds() - startMs);
} catch (WakeupException | InterruptException e) {
throw e;
} catch (Exception e) {
log.error("User provided listener {} failed on invocation of onPartitionsRevoked for partitions {}",
listener.getClass().getName(), revokedPartitions, e);
return e;
}
return null;
}
private Exception invokePartitionsLost(final SortedSet<TopicPartition> lostPartitions) {
log.info("Lost previously assigned partitions {}", Utils.join(lostPartitions, ", "));
Set<TopicPartition> lostPausedPartitions = subscriptions.pausedPartitions();
lostPausedPartitions.retainAll(lostPartitions);
if (!lostPausedPartitions.isEmpty())
log.info("The pause flag in partitions [{}] will be removed due to partition lost.", Utils.join(lostPausedPartitions, ", "));
ConsumerRebalanceListener listener = subscriptions.rebalanceListener();
try {
final long startMs = time.milliseconds();
listener.onPartitionsLost(lostPartitions);
sensors.loseCallbackSensor.record(time.milliseconds() - startMs);
} catch (WakeupException | InterruptException e) {
throw e;
} catch (Exception e) {
log.error("User provided listener {} failed on invocation of onPartitionsLost for partitions {}",
listener.getClass().getName(), lostPartitions, e);
return e;
}
return null;
}
@Override
protected void onJoinComplete(int generation,
String memberId,
String assignmentStrategy,
ByteBuffer assignmentBuffer) {
log.debug("Executing onJoinComplete with generation {} and memberId {}", generation, memberId);
// Only the leader is responsible for monitoring for metadata changes (i.e. partition changes)
if (!isLeader)
assignmentSnapshot = null;
ConsumerPartitionAssignor assignor = lookupAssignor(assignmentStrategy);
if (assignor == null)
throw new IllegalStateException("Coordinator selected invalid assignment protocol: " + assignmentStrategy);
// Give the assignor a chance to update internal state based on the received assignment
groupMetadata = new ConsumerGroupMetadata(rebalanceConfig.groupId, generation, memberId, rebalanceConfig.groupInstanceId);
SortedSet<TopicPartition> ownedPartitions = new TreeSet<>(COMPARATOR);
ownedPartitions.addAll(subscriptions.assignedPartitions());
// should at least encode the short version
if (assignmentBuffer.remaining() < 2)
throw new IllegalStateException("There are insufficient bytes available to read assignment from the sync-group response (" +
"actual byte size " + assignmentBuffer.remaining() + ") , this is not expected; " +
"it is possible that the leader's assign function is buggy and did not return any assignment for this member, " +
"or because static member is configured and the protocol is buggy hence did not get the assignment for this member");
Assignment assignment = ConsumerProtocol.deserializeAssignment(assignmentBuffer);
SortedSet<TopicPartition> assignedPartitions = new TreeSet<>(COMPARATOR);
assignedPartitions.addAll(assignment.partitions());
if (!subscriptions.checkAssignmentMatchedSubscription(assignedPartitions)) {
final String fullReason = String.format("received assignment %s does not match the current subscription %s; " +
"it is likely that the subscription has changed since we joined the group, will re-join with current subscription",
assignment.partitions(), subscriptions.prettyString());
requestRejoin("received assignment does not match the current subscription", fullReason);
return;
}
final AtomicReference<Exception> firstException = new AtomicReference<>(null);
SortedSet<TopicPartition> addedPartitions = new TreeSet<>(COMPARATOR);
addedPartitions.addAll(assignedPartitions);
addedPartitions.removeAll(ownedPartitions);
if (protocol == RebalanceProtocol.COOPERATIVE) {
SortedSet<TopicPartition> revokedPartitions = new TreeSet<>(COMPARATOR);
revokedPartitions.addAll(ownedPartitions);
revokedPartitions.removeAll(assignedPartitions);
log.info("Updating assignment with\n" +
"\tAssigned partitions: {}\n" +
"\tCurrent owned partitions: {}\n" +
"\tAdded partitions (assigned - owned): {}\n" +
"\tRevoked partitions (owned - assigned): {}\n",
assignedPartitions,
ownedPartitions,
addedPartitions,
revokedPartitions
);
if (!revokedPartitions.isEmpty()) {
// Revoke partitions that were previously owned but no longer assigned;
// note that we should only change the assignment (or update the assignor's state)
// AFTER we've triggered the revoke callback
firstException.compareAndSet(null, invokePartitionsRevoked(revokedPartitions));
// If revoked any partitions, need to re-join the group afterwards
final String fullReason = String.format("need to revoke partitions %s as indicated " +
"by the current assignment and re-join", revokedPartitions);
requestRejoin("need to revoke partitions and re-join", fullReason);
}
}
// The leader may have assigned partitions which match our subscription pattern, but which
// were not explicitly requested, so we update the joined subscription here.
maybeUpdateJoinedSubscription(assignedPartitions);
// Catch any exception here to make sure we could complete the user callback.
firstException.compareAndSet(null, invokeOnAssignment(assignor, assignment));
// Reschedule the auto commit starting from now
if (autoCommitEnabled)
this.nextAutoCommitTimer.updateAndReset(autoCommitIntervalMs);
subscriptions.assignFromSubscribed(assignedPartitions);
// Add partitions that were not previously owned but are now assigned
firstException.compareAndSet(null, invokePartitionsAssigned(addedPartitions));
if (firstException.get() != null) {
if (firstException.get() instanceof KafkaException) {
throw (KafkaException) firstException.get();
} else {
throw new KafkaException("User rebalance callback throws an error", firstException.get());
}
}
}
void maybeUpdateSubscriptionMetadata() {
int version = metadata.updateVersion();
if (version > metadataSnapshot.version) {
Cluster cluster = metadata.fetch();
if (subscriptions.hasPatternSubscription())
updatePatternSubscription(cluster);
// Update the current snapshot, which will be used to check for subscription
// changes that would require a rebalance (e.g. new partitions).
metadataSnapshot = new MetadataSnapshot(subscriptions, cluster, version);
}
}
private boolean coordinatorUnknownAndUnreadySync(Timer timer) {
return coordinatorUnknown() && !ensureCoordinatorReady(timer);
}
private boolean coordinatorUnknownAndUnreadyAsync() {
return coordinatorUnknown() && !ensureCoordinatorReadyAsync();
}
/**
* Poll for coordinator events. This ensures that the coordinator is known and that the consumer
* has joined the group (if it is using group management). This also handles periodic offset commits
* if they are enabled.
* <p>
* Returns early if the timeout expires or if waiting on rejoin is not required
*
* @param timer Timer bounding how long this method can block
* @param waitForJoinGroup Boolean flag indicating if we should wait until re-join group completes
* @throws KafkaException if the rebalance callback throws an exception
* @return true iff the operation succeeded
*/
public boolean poll(Timer timer, boolean waitForJoinGroup) {
maybeUpdateSubscriptionMetadata();
invokeCompletedOffsetCommitCallbacks();
if (subscriptions.hasAutoAssignedPartitions()) {
if (protocol == null) {
throw new IllegalStateException("User configured " + ConsumerConfig.PARTITION_ASSIGNMENT_STRATEGY_CONFIG +
" to empty while trying to subscribe for group protocol to auto assign partitions");
}
// Always update the heartbeat last poll time so that the heartbeat thread does not leave the
// group proactively due to application inactivity even if (say) the coordinator cannot be found.
pollHeartbeat(timer.currentTimeMs());
if (coordinatorUnknownAndUnreadySync(timer)) {
return false;
}
if (rejoinNeededOrPending()) {
// due to a race condition between the initial metadata fetch and the initial rebalance,
// we need to ensure that the metadata is fresh before joining initially. This ensures
// that we have matched the pattern against the cluster's topics at least once before joining.
if (subscriptions.hasPatternSubscription()) {
// For consumer group that uses pattern-based subscription, after a topic is created,
// any consumer that discovers the topic after metadata refresh can trigger rebalance
// across the entire consumer group. Multiple rebalances can be triggered after one topic
// creation if consumers refresh metadata at vastly different times. We can significantly
// reduce the number of rebalances caused by single topic creation by asking consumer to
// refresh metadata before re-joining the group as long as the refresh backoff time has
// passed.
if (this.metadata.timeToAllowUpdate(timer.currentTimeMs()) == 0) {
this.metadata.requestUpdate();
}
if (!client.ensureFreshMetadata(timer)) {
return false;
}
maybeUpdateSubscriptionMetadata();
}
// if not wait for join group, we would just use a timer of 0
if (!ensureActiveGroup(waitForJoinGroup ? timer : time.timer(0L))) {
// since we may use a different timer in the callee, we'd still need
// to update the original timer's current time after the call
timer.update(time.milliseconds());
return false;
}
}
} else {
// For manually assigned partitions, we do not try to pro-actively lookup coordinator;
// instead we only try to refresh metadata when necessary.
// If connections to all nodes fail, wakeups triggered while attempting to send fetch
// requests result in polls returning immediately, causing a tight loop of polls. Without
// the wakeup, poll() with no channels would block for the timeout, delaying re-connection.
// awaitMetadataUpdate() in ensureCoordinatorReady initiates new connections with configured backoff and avoids the busy loop.
if (metadata.updateRequested() && !client.hasReadyNodes(timer.currentTimeMs())) {
client.awaitMetadataUpdate(timer);
}
// if there is pending coordinator requests, ensure they have a chance to be transmitted.
client.pollNoWakeup();
}
maybeAutoCommitOffsetsAsync(timer.currentTimeMs());
return true;
}
/**
* Return the time to the next needed invocation of {@link ConsumerNetworkClient#poll(Timer)}.
* @param now current time in milliseconds
* @return the maximum time in milliseconds the caller should wait before the next invocation of poll()
*/
public long timeToNextPoll(long now) {
if (!autoCommitEnabled)
return timeToNextHeartbeat(now);
return Math.min(nextAutoCommitTimer.remainingMs(), timeToNextHeartbeat(now));
}
private void updateGroupSubscription(Set<String> topics) {
// the leader will begin watching for changes to any of the topics the group is interested in,
// which ensures that all metadata changes will eventually be seen
if (this.subscriptions.groupSubscribe(topics))
metadata.requestUpdateForNewTopics();
// update metadata (if needed) and keep track of the metadata used for assignment so that
// we can check after rebalance completion whether anything has changed
if (!client.ensureFreshMetadata(time.timer(Long.MAX_VALUE)))
throw new TimeoutException();
maybeUpdateSubscriptionMetadata();
}
private boolean isAssignFromSubscribedTopicsAssignor(String name) {
return ASSIGN_FROM_SUBSCRIBED_ASSIGNORS.contains(name);
}
/**
* user-customized assignor may have created some topics that are not in the subscription list
* and assign their partitions to the members; in this case we would like to update the leader's
* own metadata with the newly added topics so that it will not trigger a subsequent rebalance
* when these topics gets updated from metadata refresh.
*
* We skip the check for in-product assignors since this will not happen in in-product assignors.
*
* TODO: this is a hack and not something we want to support long-term unless we push regex into the protocol
* we may need to modify the ConsumerPartitionAssignor API to better support this case.
*
* @param assignorName the selected assignor name
* @param assignments the assignments after assignor assigned
* @param allSubscribedTopics all consumers' subscribed topics
*/
private void maybeUpdateGroupSubscription(String assignorName,
Map<String, Assignment> assignments,
Set<String> allSubscribedTopics) {
if (!isAssignFromSubscribedTopicsAssignor(assignorName)) {
Set<String> assignedTopics = new HashSet<>();
for (Assignment assigned : assignments.values()) {
for (TopicPartition tp : assigned.partitions())
assignedTopics.add(tp.topic());
}
if (!assignedTopics.containsAll(allSubscribedTopics)) {
SortedSet<String> notAssignedTopics = new TreeSet<>(allSubscribedTopics);
notAssignedTopics.removeAll(assignedTopics);
log.warn("The following subscribed topics are not assigned to any members: {} ", notAssignedTopics);
}
if (!allSubscribedTopics.containsAll(assignedTopics)) {
SortedSet<String> newlyAddedTopics = new TreeSet<>(assignedTopics);
newlyAddedTopics.removeAll(allSubscribedTopics);
log.info("The following not-subscribed topics are assigned, and their metadata will be " +
"fetched from the brokers: {}", newlyAddedTopics);
allSubscribedTopics.addAll(newlyAddedTopics);
updateGroupSubscription(allSubscribedTopics);
}
}
}
@Override
protected Map<String, ByteBuffer> onLeaderElected(String leaderId,
String assignmentStrategy,
List<JoinGroupResponseData.JoinGroupResponseMember> allSubscriptions,
boolean skipAssignment) {
ConsumerPartitionAssignor assignor = lookupAssignor(assignmentStrategy);
if (assignor == null)
throw new IllegalStateException("Coordinator selected invalid assignment protocol: " + assignmentStrategy);
String assignorName = assignor.name();
Set<String> allSubscribedTopics = new HashSet<>();
Map<String, Subscription> subscriptions = new HashMap<>();
// collect all the owned partitions
Map<String, List<TopicPartition>> ownedPartitions = new HashMap<>();
for (JoinGroupResponseData.JoinGroupResponseMember memberSubscription : allSubscriptions) {
Subscription subscription = ConsumerProtocol.deserializeSubscription(ByteBuffer.wrap(memberSubscription.metadata()));
subscription.setGroupInstanceId(Optional.ofNullable(memberSubscription.groupInstanceId()));
subscriptions.put(memberSubscription.memberId(), subscription);
allSubscribedTopics.addAll(subscription.topics());
ownedPartitions.put(memberSubscription.memberId(), subscription.ownedPartitions());
}
// the leader will begin watching for changes to any of the topics the group is interested in,
// which ensures that all metadata changes will eventually be seen
updateGroupSubscription(allSubscribedTopics);
isLeader = true;
if (skipAssignment) {
log.info("Skipped assignment for returning static leader at generation {}. The static leader " +
"will continue with its existing assignment.", generation().generationId);
assignmentSnapshot = metadataSnapshot;
return Collections.emptyMap();
}
log.debug("Performing assignment using strategy {} with subscriptions {}", assignorName, subscriptions);
Map<String, Assignment> assignments = assignor.assign(metadata.fetch(), new GroupSubscription(subscriptions)).groupAssignment();
// skip the validation for built-in cooperative sticky assignor since we've considered
// the "generation" of ownedPartition inside the assignor
if (protocol == RebalanceProtocol.COOPERATIVE && !assignorName.equals(COOPERATIVE_STICKY_ASSIGNOR_NAME)) {
validateCooperativeAssignment(ownedPartitions, assignments);
}
maybeUpdateGroupSubscription(assignorName, assignments, allSubscribedTopics);
// metadataSnapshot could be updated when the subscription is updated therefore
// we must take the assignment snapshot after.
assignmentSnapshot = metadataSnapshot;
log.info("Finished assignment for group at generation {}: {}", generation().generationId, assignments);
Map<String, ByteBuffer> groupAssignment = new HashMap<>();
for (Map.Entry<String, Assignment> assignmentEntry : assignments.entrySet()) {
ByteBuffer buffer = ConsumerProtocol.serializeAssignment(assignmentEntry.getValue());
groupAssignment.put(assignmentEntry.getKey(), buffer);
}
return groupAssignment;
}
/**
* Used by COOPERATIVE rebalance protocol only.
*
* Validate the assignments returned by the assignor such that no owned partitions are going to
* be reassigned to a different consumer directly: if the assignor wants to reassign an owned partition,
* it must first remove it from the new assignment of the current owner so that it is not assigned to any
* member, and then in the next rebalance it can finally reassign those partitions not owned by anyone to consumers.
*/
private void validateCooperativeAssignment(final Map<String, List<TopicPartition>> ownedPartitions,
final Map<String, Assignment> assignments) {
Set<TopicPartition> totalRevokedPartitions = new HashSet<>();
SortedSet<TopicPartition> totalAddedPartitions = new TreeSet<>(COMPARATOR);
for (final Map.Entry<String, Assignment> entry : assignments.entrySet()) {
final Assignment assignment = entry.getValue();
final Set<TopicPartition> addedPartitions = new HashSet<>(assignment.partitions());
addedPartitions.removeAll(ownedPartitions.get(entry.getKey()));
final Set<TopicPartition> revokedPartitions = new HashSet<>(ownedPartitions.get(entry.getKey()));
revokedPartitions.removeAll(assignment.partitions());
totalAddedPartitions.addAll(addedPartitions);
totalRevokedPartitions.addAll(revokedPartitions);
}
// if there are overlap between revoked partitions and added partitions, it means some partitions
// immediately gets re-assigned to another member while it is still claimed by some member
totalAddedPartitions.retainAll(totalRevokedPartitions);
if (!totalAddedPartitions.isEmpty()) {
log.error("With the COOPERATIVE protocol, owned partitions cannot be " +
"reassigned to other members; however the assignor has reassigned partitions {} which are still owned " +
"by some members", totalAddedPartitions);
throw new IllegalStateException("Assignor supporting the COOPERATIVE protocol violates its requirements");
}
}
@Override
protected boolean onJoinPrepare(Timer timer, int generation, String memberId) {
log.debug("Executing onJoinPrepare with generation {} and memberId {}", generation, memberId);
if (joinPrepareTimer == null) {
// We should complete onJoinPrepare before rebalanceTimeout,
// and continue to join group to avoid member got kicked out from group
joinPrepareTimer = time.timer(rebalanceConfig.rebalanceTimeoutMs);
} else {
joinPrepareTimer.update();
}
// async commit offsets prior to rebalance if auto-commit enabled
// and there is no in-flight offset commit request
if (autoCommitEnabled && autoCommitOffsetRequestFuture == null) {
maybeMarkPartitionsPendingRevocation();
autoCommitOffsetRequestFuture = maybeAutoCommitOffsetsAsync();
}
// wait for commit offset response before timer expired
if (autoCommitOffsetRequestFuture != null) {
Timer pollTimer = timer.remainingMs() < joinPrepareTimer.remainingMs() ?
timer : joinPrepareTimer;
client.poll(autoCommitOffsetRequestFuture, pollTimer);
joinPrepareTimer.update();
// Keep retrying/waiting the offset commit when:
// 1. offset commit haven't done (and joinPrepareTimer not expired)
// 2. failed with retryable exception (and joinPrepareTimer not expired)
// Otherwise, continue to revoke partitions, ex:
// 1. if joinPrepareTime has expired
// 2. if offset commit failed with no-retryable exception
// 3. if offset commit success
boolean onJoinPrepareAsyncCommitCompleted = true;
if (joinPrepareTimer.isExpired()) {
log.error("Asynchronous auto-commit of offsets failed: joinPrepare timeout. Will continue to join group");
} else if (!autoCommitOffsetRequestFuture.isDone()) {
onJoinPrepareAsyncCommitCompleted = false;
} else if (autoCommitOffsetRequestFuture.failed() && autoCommitOffsetRequestFuture.isRetriable()) {
log.debug("Asynchronous auto-commit of offsets failed with retryable error: {}. Will retry it.",
autoCommitOffsetRequestFuture.exception().getMessage());
onJoinPrepareAsyncCommitCompleted = false;
} else if (autoCommitOffsetRequestFuture.failed() && !autoCommitOffsetRequestFuture.isRetriable()) {
log.error("Asynchronous auto-commit of offsets failed: {}. Will continue to join group.",
autoCommitOffsetRequestFuture.exception().getMessage());
}
if (autoCommitOffsetRequestFuture.isDone()) {
autoCommitOffsetRequestFuture = null;
}
if (!onJoinPrepareAsyncCommitCompleted) {
pollTimer.sleep(Math.min(pollTimer.remainingMs(), rebalanceConfig.retryBackoffMs));
timer.update();
return false;
}
}
// the generation / member-id can possibly be reset by the heartbeat thread
// upon getting errors or heartbeat timeouts; in this case whatever is previously
// owned partitions would be lost, we should trigger the callback and cleanup the assignment;
// otherwise we can proceed normally and revoke the partitions depending on the protocol,
// and in that case we should only change the assignment AFTER the revoke callback is triggered
// so that users can still access the previously owned partitions to commit offsets etc.
Exception exception = null;
final SortedSet<TopicPartition> revokedPartitions = new TreeSet<>(COMPARATOR);
if (generation == Generation.NO_GENERATION.generationId ||
memberId.equals(Generation.NO_GENERATION.memberId)) {
revokedPartitions.addAll(subscriptions.assignedPartitions());
if (!revokedPartitions.isEmpty()) {
log.info("Giving away all assigned partitions as lost since generation/memberID has been reset," +
"indicating that consumer is in old state or no longer part of the group");
exception = invokePartitionsLost(revokedPartitions);
subscriptions.assignFromSubscribed(Collections.emptySet());
}
} else {
switch (protocol) {
case EAGER:
// revoke all partitions
revokedPartitions.addAll(subscriptions.assignedPartitions());
exception = invokePartitionsRevoked(revokedPartitions);
subscriptions.assignFromSubscribed(Collections.emptySet());
break;
case COOPERATIVE:
// only revoke those partitions that are not in the subscription any more.
Set<TopicPartition> ownedPartitions = new HashSet<>(subscriptions.assignedPartitions());
revokedPartitions.addAll(ownedPartitions.stream()
.filter(tp -> !subscriptions.subscription().contains(tp.topic()))
.collect(Collectors.toSet()));
if (!revokedPartitions.isEmpty()) {
exception = invokePartitionsRevoked(revokedPartitions);
ownedPartitions.removeAll(revokedPartitions);
subscriptions.assignFromSubscribed(ownedPartitions);
}
break;
}
}
isLeader = false;
subscriptions.resetGroupSubscription();
joinPrepareTimer = null;
autoCommitOffsetRequestFuture = null;
timer.update();
if (exception != null) {
throw new KafkaException("User rebalance callback throws an error", exception);
}
return true;
}
private void maybeMarkPartitionsPendingRevocation() {
if (protocol != RebalanceProtocol.EAGER) {
return;
}
// When asynchronously committing offsets prior to the revocation of a set of partitions, there will be a
// window of time between when the offset commit is sent and when it returns and revocation completes. It is
// possible for pending fetches for these partitions to return during this time, which means the application's
// position may get ahead of the committed position prior to revocation. This can cause duplicate consumption.
// To prevent this, we mark the partitions as "pending revocation," which stops the Fetcher from sending new
// fetches or returning data from previous fetches to the user.
Set<TopicPartition> partitions = subscriptions.assignedPartitions();
log.debug("Marking assigned partitions pending for revocation: {}", partitions);
subscriptions.markPendingRevocation(partitions);
}
@Override
public void onLeavePrepare() {
// Save the current Generation, as the hb thread can change it at any time
final Generation currentGeneration = generation();
log.debug("Executing onLeavePrepare with generation {}", currentGeneration);
// we should reset assignment and trigger the callback before leaving group
SortedSet<TopicPartition> droppedPartitions = new TreeSet<>(COMPARATOR);
droppedPartitions.addAll(subscriptions.assignedPartitions());
if (subscriptions.hasAutoAssignedPartitions() && !droppedPartitions.isEmpty()) {
final Exception e;
if ((currentGeneration.generationId == Generation.NO_GENERATION.generationId ||
currentGeneration.memberId.equals(Generation.NO_GENERATION.memberId)) ||
rebalanceInProgress()) {
e = invokePartitionsLost(droppedPartitions);
} else {
e = invokePartitionsRevoked(droppedPartitions);
}
subscriptions.assignFromSubscribed(Collections.emptySet());
if (e != null) {
throw new KafkaException("User rebalance callback throws an error", e);
}
}
}
/**
* @throws KafkaException if the callback throws exception
*/
@Override
public boolean rejoinNeededOrPending() {
if (!subscriptions.hasAutoAssignedPartitions())
return false;
// we need to rejoin if we performed the assignment and metadata has changed;
// also for those owned-but-no-longer-existed partitions we should drop them as lost
if (assignmentSnapshot != null && !assignmentSnapshot.matches(metadataSnapshot)) {
final String fullReason = String.format("cached metadata has changed from %s at the beginning of the rebalance to %s",
assignmentSnapshot, metadataSnapshot);
requestRejoinIfNecessary("cached metadata has changed", fullReason);
return true;
}
// we need to join if our subscription has changed since the last join
if (joinedSubscription != null && !joinedSubscription.equals(subscriptions.subscription())) {
final String fullReason = String.format("subscription has changed from %s at the beginning of the rebalance to %s",
joinedSubscription, subscriptions.subscription());
requestRejoinIfNecessary("subscription has changed", fullReason);
return true;
}
return super.rejoinNeededOrPending();
}
/**
* Refresh the committed offsets for provided partitions.
*
* @param timer Timer bounding how long this method can block
* @return true iff the operation completed within the timeout
*/
public boolean refreshCommittedOffsetsIfNeeded(Timer timer) {
final Set<TopicPartition> initializingPartitions = subscriptions.initializingPartitions();
final Map<TopicPartition, OffsetAndMetadata> offsets = fetchCommittedOffsets(initializingPartitions, timer);
if (offsets == null) return false;
for (final Map.Entry<TopicPartition, OffsetAndMetadata> entry : offsets.entrySet()) {
final TopicPartition tp = entry.getKey();
final OffsetAndMetadata offsetAndMetadata = entry.getValue();
if (offsetAndMetadata != null) {
// first update the epoch if necessary
entry.getValue().leaderEpoch().ifPresent(epoch -> this.metadata.updateLastSeenEpochIfNewer(entry.getKey(), epoch));
// it's possible that the partition is no longer assigned when the response is received,
// so we need to ignore seeking if that's the case
if (this.subscriptions.isAssigned(tp)) {
final ConsumerMetadata.LeaderAndEpoch leaderAndEpoch = metadata.currentLeader(tp);
final SubscriptionState.FetchPosition position = new SubscriptionState.FetchPosition(
offsetAndMetadata.offset(), offsetAndMetadata.leaderEpoch(),
leaderAndEpoch);
this.subscriptions.seekUnvalidated(tp, position);
log.info("Setting offset for partition {} to the committed offset {}", tp, position);
} else {
log.info("Ignoring the returned {} since its partition {} is no longer assigned",
offsetAndMetadata, tp);
}
}
}
return true;
}
/**
* Fetch the current committed offsets from the coordinator for a set of partitions.
*
* @param partitions The partitions to fetch offsets for
* @return A map from partition to the committed offset or null if the operation timed out
*/
public Map<TopicPartition, OffsetAndMetadata> fetchCommittedOffsets(final Set<TopicPartition> partitions,
final Timer timer) {
if (partitions.isEmpty()) return Collections.emptyMap();
final Generation generationForOffsetRequest = generationIfStable();
if (pendingCommittedOffsetRequest != null &&
!pendingCommittedOffsetRequest.sameRequest(partitions, generationForOffsetRequest)) {
// if we were waiting for a different request, then just clear it.
pendingCommittedOffsetRequest = null;
}
do {
if (!ensureCoordinatorReady(timer)) return null;
// contact coordinator to fetch committed offsets
final RequestFuture<Map<TopicPartition, OffsetAndMetadata>> future;
if (pendingCommittedOffsetRequest != null) {
future = pendingCommittedOffsetRequest.response;
} else {
future = sendOffsetFetchRequest(partitions);
pendingCommittedOffsetRequest = new PendingCommittedOffsetRequest(partitions, generationForOffsetRequest, future);
}
client.poll(future, timer);
if (future.isDone()) {
pendingCommittedOffsetRequest = null;
if (future.succeeded()) {
return future.value();
} else if (!future.isRetriable()) {
throw future.exception();
} else {
timer.sleep(rebalanceConfig.retryBackoffMs);
}
} else {
return null;
}
} while (timer.notExpired());
return null;
}
/**
* Return the consumer group metadata.
*
* @return the current consumer group metadata
*/
public ConsumerGroupMetadata groupMetadata() {
return groupMetadata;
}
/**
* @throws KafkaException if the rebalance callback throws exception
*/
public void close(final Timer timer) {
// we do not need to re-enable wakeups since we are closing already
client.disableWakeups();
try {
maybeAutoCommitOffsetsSync(timer);
while (pendingAsyncCommits.get() > 0 && timer.notExpired()) {
ensureCoordinatorReady(timer);
client.poll(timer);
invokeCompletedOffsetCommitCallbacks();
}
} finally {
super.close(timer);
}
}
// visible for testing
void invokeCompletedOffsetCommitCallbacks() {
if (asyncCommitFenced.get()) {
throw new FencedInstanceIdException("Get fenced exception for group.instance.id "
+ rebalanceConfig.groupInstanceId.orElse("unset_instance_id")
+ ", current member.id is " + memberId());
}
while (true) {
OffsetCommitCompletion completion = completedOffsetCommits.poll();
if (completion == null) {
break;
}
completion.invoke();
}
}
public RequestFuture<Void> commitOffsetsAsync(final Map<TopicPartition, OffsetAndMetadata> offsets, final OffsetCommitCallback callback) {
invokeCompletedOffsetCommitCallbacks();
RequestFuture<Void> future = null;
if (offsets.isEmpty()) {
// No need to check coordinator if offsets is empty since commit of empty offsets is completed locally.
future = doCommitOffsetsAsync(offsets, callback);
} else if (!coordinatorUnknownAndUnreadyAsync()) {
// we need to make sure coordinator is ready before committing, since
// this is for async committing we do not try to block, but just try once to
// clear the previous discover-coordinator future, resend, or get responses;
// if the coordinator is not ready yet then we would just proceed and put that into the
// pending requests, and future poll calls would still try to complete them.
//
// the key here though is that we have to try sending the discover-coordinator if
// it's not known or ready, since this is the only place we can send such request
// under manual assignment (there we would not have heartbeat thread trying to auto-rediscover
// the coordinator).
future = doCommitOffsetsAsync(offsets, callback);
} else {
// we don't know the current coordinator, so try to find it and then send the commit
// or fail (we don't want recursive retries which can cause offset commits to arrive
// out of order). Note that there may be multiple offset commits chained to the same
// coordinator lookup request. This is fine because the listeners will be invoked in
// the same order that they were added. Note also that AbstractCoordinator prevents
// multiple concurrent coordinator lookup requests.
pendingAsyncCommits.incrementAndGet();
lookupCoordinator().addListener(new RequestFutureListener<Void>() {
@Override
public void onSuccess(Void value) {
pendingAsyncCommits.decrementAndGet();
doCommitOffsetsAsync(offsets, callback);
client.pollNoWakeup();
}
@Override
public void onFailure(RuntimeException e) {
pendingAsyncCommits.decrementAndGet();
completedOffsetCommits.add(new OffsetCommitCompletion(callback, offsets,
new RetriableCommitFailedException(e)));
}
});
}
// ensure the commit has a chance to be transmitted (without blocking on its completion).
// Note that commits are treated as heartbeats by the coordinator, so there is no need to
// explicitly allow heartbeats through delayed task execution.
client.pollNoWakeup();
return future;
}
private RequestFuture<Void> doCommitOffsetsAsync(final Map<TopicPartition, OffsetAndMetadata> offsets, final OffsetCommitCallback callback) {
RequestFuture<Void> future = sendOffsetCommitRequest(offsets);
final OffsetCommitCallback cb = callback == null ? defaultOffsetCommitCallback : callback;
future.addListener(new RequestFutureListener<Void>() {
@Override
public void onSuccess(Void value) {
if (interceptors != null)
interceptors.onCommit(offsets);
completedOffsetCommits.add(new OffsetCommitCompletion(cb, offsets, null));
}
@Override
public void onFailure(RuntimeException e) {
Exception commitException = e;
if (e instanceof RetriableException) {
commitException = new RetriableCommitFailedException(e);
}
completedOffsetCommits.add(new OffsetCommitCompletion(cb, offsets, commitException));
if (commitException instanceof FencedInstanceIdException) {
asyncCommitFenced.set(true);
}
}
});
return future;
}
/**
* Commit offsets synchronously. This method will retry until the commit completes successfully
* or an unrecoverable error is encountered.
* @param offsets The offsets to be committed
* @throws org.apache.kafka.common.errors.AuthorizationException if the consumer is not authorized to the group
* or to any of the specified partitions. See the exception for more details
* @throws CommitFailedException if an unrecoverable error occurs before the commit can be completed
* @throws FencedInstanceIdException if a static member gets fenced
* @return If the offset commit was successfully sent and a successful response was received from
* the coordinator
*/
public boolean commitOffsetsSync(Map<TopicPartition, OffsetAndMetadata> offsets, Timer timer) {
invokeCompletedOffsetCommitCallbacks();
if (offsets.isEmpty())
return true;
do {
if (coordinatorUnknownAndUnreadySync(timer)) {
return false;
}
RequestFuture<Void> future = sendOffsetCommitRequest(offsets);
client.poll(future, timer);
// We may have had in-flight offset commits when the synchronous commit began. If so, ensure that
// the corresponding callbacks are invoked prior to returning in order to preserve the order that
// the offset commits were applied.
invokeCompletedOffsetCommitCallbacks();
if (future.succeeded()) {
if (interceptors != null)
interceptors.onCommit(offsets);
return true;
}
if (future.failed() && !future.isRetriable())
throw future.exception();
timer.sleep(rebalanceConfig.retryBackoffMs);
} while (timer.notExpired());
return false;
}
private void maybeAutoCommitOffsetsSync(Timer timer) {
if (autoCommitEnabled) {
Map<TopicPartition, OffsetAndMetadata> allConsumedOffsets = subscriptions.allConsumed();
try {
log.debug("Sending synchronous auto-commit of offsets {}", allConsumedOffsets);
if (!commitOffsetsSync(allConsumedOffsets, timer))
log.debug("Auto-commit of offsets {} timed out before completion", allConsumedOffsets);
} catch (WakeupException | InterruptException e) {
log.debug("Auto-commit of offsets {} was interrupted before completion", allConsumedOffsets);
// rethrow wakeups since they are triggered by the user
throw e;
} catch (Exception e) {
// consistent with async auto-commit failures, we do not propagate the exception
log.warn("Synchronous auto-commit of offsets {} failed: {}", allConsumedOffsets, e.getMessage());
}
}
}
public void maybeAutoCommitOffsetsAsync(long now) {
if (autoCommitEnabled) {
nextAutoCommitTimer.update(now);
if (nextAutoCommitTimer.isExpired()) {
nextAutoCommitTimer.reset(autoCommitIntervalMs);
autoCommitOffsetsAsync();
}
}
}
private RequestFuture<Void> autoCommitOffsetsAsync() {
Map<TopicPartition, OffsetAndMetadata> allConsumedOffsets = subscriptions.allConsumed();
log.debug("Sending asynchronous auto-commit of offsets {}", allConsumedOffsets);
return commitOffsetsAsync(allConsumedOffsets, (offsets, exception) -> {
if (exception != null) {
if (exception instanceof RetriableCommitFailedException) {
log.debug("Asynchronous auto-commit of offsets {} failed due to retriable error: {}", offsets,
exception);
nextAutoCommitTimer.updateAndReset(rebalanceConfig.retryBackoffMs);
} else {
log.warn("Asynchronous auto-commit of offsets {} failed: {}", offsets, exception.getMessage());
}
} else {
log.debug("Completed asynchronous auto-commit of offsets {}", offsets);
}
});
}
private RequestFuture<Void> maybeAutoCommitOffsetsAsync() {
if (autoCommitEnabled)
return autoCommitOffsetsAsync();
return null;
}
private class DefaultOffsetCommitCallback implements OffsetCommitCallback {
@Override
public void onComplete(Map<TopicPartition, OffsetAndMetadata> offsets, Exception exception) {
if (exception != null)
log.error("Offset commit with offsets {} failed", offsets, exception);
}
}
/**
* Commit offsets for the specified list of topics and partitions. This is a non-blocking call
* which returns a request future that can be polled in the case of a synchronous commit or ignored in the
* asynchronous case.
*
* NOTE: This is visible only for testing
*
* @param offsets The list of offsets per partition that should be committed.
* @return A request future whose value indicates whether the commit was successful or not
*/
RequestFuture<Void> sendOffsetCommitRequest(final Map<TopicPartition, OffsetAndMetadata> offsets) {
if (offsets.isEmpty())
return RequestFuture.voidSuccess();
Node coordinator = checkAndGetCoordinator();
if (coordinator == null)
return RequestFuture.coordinatorNotAvailable();
// create the offset commit request
Map<String, OffsetCommitRequestData.OffsetCommitRequestTopic> requestTopicDataMap = new HashMap<>();
for (Map.Entry<TopicPartition, OffsetAndMetadata> entry : offsets.entrySet()) {
TopicPartition topicPartition = entry.getKey();
OffsetAndMetadata offsetAndMetadata = entry.getValue();
if (offsetAndMetadata.offset() < 0) {
return RequestFuture.failure(new IllegalArgumentException("Invalid offset: " + offsetAndMetadata.offset()));
}
OffsetCommitRequestData.OffsetCommitRequestTopic topic = requestTopicDataMap
.getOrDefault(topicPartition.topic(),
new OffsetCommitRequestData.OffsetCommitRequestTopic()
.setName(topicPartition.topic())
);
topic.partitions().add(new OffsetCommitRequestData.OffsetCommitRequestPartition()
.setPartitionIndex(topicPartition.partition())
.setCommittedOffset(offsetAndMetadata.offset())
.setCommittedLeaderEpoch(offsetAndMetadata.leaderEpoch().orElse(RecordBatch.NO_PARTITION_LEADER_EPOCH))
.setCommittedMetadata(offsetAndMetadata.metadata())
);
requestTopicDataMap.put(topicPartition.topic(), topic);
}
final Generation generation;
final String groupInstanceId;
if (subscriptions.hasAutoAssignedPartitions()) {
generation = generationIfStable();
groupInstanceId = rebalanceConfig.groupInstanceId.orElse(null);
// if the generation is null, we are not part of an active group (and we expect to be).
// the only thing we can do is fail the commit and let the user rejoin the group in poll().
if (generation == null) {
log.info("Failing OffsetCommit request since the consumer is not part of an active group");
if (rebalanceInProgress()) {
// if the client knows it is already rebalancing, we can use RebalanceInProgressException instead of
// CommitFailedException to indicate this is not a fatal error
return RequestFuture.failure(new RebalanceInProgressException("Offset commit cannot be completed since the " +
"consumer is undergoing a rebalance for auto partition assignment. You can try completing the rebalance " +
"by calling poll() and then retry the operation."));
} else {
return RequestFuture.failure(new CommitFailedException("Offset commit cannot be completed since the " +
"consumer is not part of an active group for auto partition assignment; it is likely that the consumer " +
"was kicked out of the group."));
}
}
} else {
generation = Generation.NO_GENERATION;
groupInstanceId = null;
}
OffsetCommitRequest.Builder builder = new OffsetCommitRequest.Builder(
new OffsetCommitRequestData()
.setGroupId(this.rebalanceConfig.groupId)
.setGenerationId(generation.generationId)
.setMemberId(generation.memberId)
.setGroupInstanceId(groupInstanceId)
.setTopics(new ArrayList<>(requestTopicDataMap.values()))
);
log.trace("Sending OffsetCommit request with {} to coordinator {}", offsets, coordinator);
return client.send(coordinator, builder)
.compose(new OffsetCommitResponseHandler(offsets, generation));
}
private class OffsetCommitResponseHandler extends CoordinatorResponseHandler<OffsetCommitResponse, Void> {
private final Map<TopicPartition, OffsetAndMetadata> offsets;
private OffsetCommitResponseHandler(Map<TopicPartition, OffsetAndMetadata> offsets, Generation generation) {
super(generation);
this.offsets = offsets;
}
@Override
public void handle(OffsetCommitResponse commitResponse, RequestFuture<Void> future) {
sensors.commitSensor.record(response.requestLatencyMs());
Set<String> unauthorizedTopics = new HashSet<>();
for (OffsetCommitResponseData.OffsetCommitResponseTopic topic : commitResponse.data().topics()) {
for (OffsetCommitResponseData.OffsetCommitResponsePartition partition : topic.partitions()) {
TopicPartition tp = new TopicPartition(topic.name(), partition.partitionIndex());
OffsetAndMetadata offsetAndMetadata = this.offsets.get(tp);
long offset = offsetAndMetadata.offset();
Errors error = Errors.forCode(partition.errorCode());
if (error == Errors.NONE) {
log.debug("Committed offset {} for partition {}", offset, tp);
} else {
if (error.exception() instanceof RetriableException) {
log.warn("Offset commit failed on partition {} at offset {}: {}", tp, offset, error.message());
} else {
log.error("Offset commit failed on partition {} at offset {}: {}", tp, offset, error.message());
}
if (error == Errors.GROUP_AUTHORIZATION_FAILED) {
future.raise(GroupAuthorizationException.forGroupId(rebalanceConfig.groupId));
return;
} else if (error == Errors.TOPIC_AUTHORIZATION_FAILED) {
unauthorizedTopics.add(tp.topic());
} else if (error == Errors.OFFSET_METADATA_TOO_LARGE
|| error == Errors.INVALID_COMMIT_OFFSET_SIZE) {
// raise the error to the user
future.raise(error);
return;
} else if (error == Errors.COORDINATOR_LOAD_IN_PROGRESS
|| error == Errors.UNKNOWN_TOPIC_OR_PARTITION) {
// just retry
future.raise(error);
return;
} else if (error == Errors.COORDINATOR_NOT_AVAILABLE
|| error == Errors.NOT_COORDINATOR
|| error == Errors.REQUEST_TIMED_OUT) {
markCoordinatorUnknown(error);
future.raise(error);
return;
} else if (error == Errors.FENCED_INSTANCE_ID) {
log.info("OffsetCommit failed with {} due to group instance id {} fenced", sentGeneration, rebalanceConfig.groupInstanceId);
// if the generation has changed or we are not in rebalancing, do not raise the fatal error but rebalance-in-progress
if (generationUnchanged()) {
future.raise(error);
} else {
KafkaException exception;
synchronized (ConsumerCoordinator.this) {
if (ConsumerCoordinator.this.state == MemberState.PREPARING_REBALANCE) {
exception = new RebalanceInProgressException("Offset commit cannot be completed since the " +
"consumer member's old generation is fenced by its group instance id, it is possible that " +
"this consumer has already participated another rebalance and got a new generation");
} else {
exception = new CommitFailedException();
}
}
future.raise(exception);
}
return;
} else if (error == Errors.REBALANCE_IN_PROGRESS) {
/* Consumer should not try to commit offset in between join-group and sync-group,
* and hence on broker-side it is not expected to see a commit offset request
* during CompletingRebalance phase; if it ever happens then broker would return
* this error to indicate that we are still in the middle of a rebalance.
* In this case we would throw a RebalanceInProgressException,
* request re-join but do not reset generations. If the callers decide to retry they
* can go ahead and call poll to finish up the rebalance first, and then try commit again.
*/
requestRejoin("offset commit failed since group is already rebalancing");
future.raise(new RebalanceInProgressException("Offset commit cannot be completed since the " +
"consumer group is executing a rebalance at the moment. You can try completing the rebalance " +
"by calling poll() and then retry commit again"));
return;
} else if (error == Errors.UNKNOWN_MEMBER_ID
|| error == Errors.ILLEGAL_GENERATION) {
log.info("OffsetCommit failed with {}: {}", sentGeneration, error.message());
// only need to reset generation and re-join group if generation has not changed or we are not in rebalancing;
// otherwise only raise rebalance-in-progress error
KafkaException exception;
synchronized (ConsumerCoordinator.this) {
if (!generationUnchanged() && ConsumerCoordinator.this.state == MemberState.PREPARING_REBALANCE) {
exception = new RebalanceInProgressException("Offset commit cannot be completed since the " +
"consumer member's generation is already stale, meaning it has already participated another rebalance and " +
"got a new generation. You can try completing the rebalance by calling poll() and then retry commit again");
} else {
// don't reset generation member ID when ILLEGAL_GENERATION, since the member might be still valid
resetStateOnResponseError(ApiKeys.OFFSET_COMMIT, error, error != Errors.ILLEGAL_GENERATION);
exception = new CommitFailedException();
}
}
future.raise(exception);
return;
} else {
future.raise(new KafkaException("Unexpected error in commit: " + error.message()));
return;
}
}
}
}
if (!unauthorizedTopics.isEmpty()) {
log.error("Not authorized to commit to topics {}", unauthorizedTopics);
future.raise(new TopicAuthorizationException(unauthorizedTopics));
} else {
future.complete(null);
}
}
}
/**
* Fetch the committed offsets for a set of partitions. This is a non-blocking call. The
* returned future can be polled to get the actual offsets returned from the broker.
*
* @param partitions The set of partitions to get offsets for.
* @return A request future containing the committed offsets.
*/
private RequestFuture<Map<TopicPartition, OffsetAndMetadata>> sendOffsetFetchRequest(Set<TopicPartition> partitions) {
Node coordinator = checkAndGetCoordinator();
if (coordinator == null)
return RequestFuture.coordinatorNotAvailable();
log.debug("Fetching committed offsets for partitions: {}", partitions);
// construct the request
OffsetFetchRequest.Builder requestBuilder =
new OffsetFetchRequest.Builder(this.rebalanceConfig.groupId, true, new ArrayList<>(partitions), throwOnFetchStableOffsetsUnsupported);
// send the request with a callback
return client.send(coordinator, requestBuilder)
.compose(new OffsetFetchResponseHandler());
}
private class OffsetFetchResponseHandler extends CoordinatorResponseHandler<OffsetFetchResponse, Map<TopicPartition, OffsetAndMetadata>> {
private OffsetFetchResponseHandler() {
super(Generation.NO_GENERATION);
}
@Override
public void handle(OffsetFetchResponse response, RequestFuture<Map<TopicPartition, OffsetAndMetadata>> future) {
Errors responseError = response.groupLevelError(rebalanceConfig.groupId);
if (responseError != Errors.NONE) {
log.debug("Offset fetch failed: {}", responseError.message());
if (responseError == Errors.COORDINATOR_LOAD_IN_PROGRESS) {
// just retry
future.raise(responseError);
} else if (responseError == Errors.NOT_COORDINATOR) {
// re-discover the coordinator and retry
markCoordinatorUnknown(responseError);
future.raise(responseError);
} else if (responseError == Errors.GROUP_AUTHORIZATION_FAILED) {
future.raise(GroupAuthorizationException.forGroupId(rebalanceConfig.groupId));
} else {
future.raise(new KafkaException("Unexpected error in fetch offset response: " + responseError.message()));
}
return;
}
Set<String> unauthorizedTopics = null;
Map<TopicPartition, OffsetFetchResponse.PartitionData> responseData =
response.partitionDataMap(rebalanceConfig.groupId);
Map<TopicPartition, OffsetAndMetadata> offsets = new HashMap<>(responseData.size());
Set<TopicPartition> unstableTxnOffsetTopicPartitions = new HashSet<>();
for (Map.Entry<TopicPartition, OffsetFetchResponse.PartitionData> entry : responseData.entrySet()) {
TopicPartition tp = entry.getKey();
OffsetFetchResponse.PartitionData partitionData = entry.getValue();
if (partitionData.hasError()) {
Errors error = partitionData.error;
log.debug("Failed to fetch offset for partition {}: {}", tp, error.message());
if (error == Errors.UNKNOWN_TOPIC_OR_PARTITION) {
future.raise(new KafkaException("Topic or Partition " + tp + " does not exist"));
return;
} else if (error == Errors.TOPIC_AUTHORIZATION_FAILED) {
if (unauthorizedTopics == null) {
unauthorizedTopics = new HashSet<>();
}
unauthorizedTopics.add(tp.topic());
} else if (error == Errors.UNSTABLE_OFFSET_COMMIT) {
unstableTxnOffsetTopicPartitions.add(tp);
} else {
future.raise(new KafkaException("Unexpected error in fetch offset response for partition " +
tp + ": " + error.message()));
return;
}
} else if (partitionData.offset >= 0) {
// record the position with the offset (-1 indicates no committed offset to fetch);
// if there's no committed offset, record as null
offsets.put(tp, new OffsetAndMetadata(partitionData.offset, partitionData.leaderEpoch, partitionData.metadata));
} else {
log.info("Found no committed offset for partition {}", tp);
offsets.put(tp, null);
}
}
if (unauthorizedTopics != null) {
future.raise(new TopicAuthorizationException(unauthorizedTopics));
} else if (!unstableTxnOffsetTopicPartitions.isEmpty()) {
// just retry
log.info("The following partitions still have unstable offsets " +
"which are not cleared on the broker side: {}" +
", this could be either " +
"transactional offsets waiting for completion, or " +
"normal offsets waiting for replication after appending to local log", unstableTxnOffsetTopicPartitions);
future.raise(new UnstableOffsetCommitException("There are unstable offsets for the requested topic partitions"));
} else {
future.complete(offsets);
}
}
}
private class ConsumerCoordinatorMetrics {
private final String metricGrpName;
private final Sensor commitSensor;
private final Sensor revokeCallbackSensor;
private final Sensor assignCallbackSensor;
private final Sensor loseCallbackSensor;
private ConsumerCoordinatorMetrics(Metrics metrics, String metricGrpPrefix) {
this.metricGrpName = metricGrpPrefix + "-coordinator-metrics";
this.commitSensor = metrics.sensor("commit-latency");
this.commitSensor.add(metrics.metricName("commit-latency-avg",
this.metricGrpName,
"The average time taken for a commit request"), new Avg());
this.commitSensor.add(metrics.metricName("commit-latency-max",
this.metricGrpName,
"The max time taken for a commit request"), new Max());
this.commitSensor.add(createMeter(metrics, metricGrpName, "commit", "commit calls"));
this.revokeCallbackSensor = metrics.sensor("partition-revoked-latency");
this.revokeCallbackSensor.add(metrics.metricName("partition-revoked-latency-avg",
this.metricGrpName,
"The average time taken for a partition-revoked rebalance listener callback"), new Avg());
this.revokeCallbackSensor.add(metrics.metricName("partition-revoked-latency-max",
this.metricGrpName,
"The max time taken for a partition-revoked rebalance listener callback"), new Max());
this.assignCallbackSensor = metrics.sensor("partition-assigned-latency");
this.assignCallbackSensor.add(metrics.metricName("partition-assigned-latency-avg",
this.metricGrpName,
"The average time taken for a partition-assigned rebalance listener callback"), new Avg());
this.assignCallbackSensor.add(metrics.metricName("partition-assigned-latency-max",
this.metricGrpName,
"The max time taken for a partition-assigned rebalance listener callback"), new Max());
this.loseCallbackSensor = metrics.sensor("partition-lost-latency");
this.loseCallbackSensor.add(metrics.metricName("partition-lost-latency-avg",
this.metricGrpName,
"The average time taken for a partition-lost rebalance listener callback"), new Avg());
this.loseCallbackSensor.add(metrics.metricName("partition-lost-latency-max",
this.metricGrpName,
"The max time taken for a partition-lost rebalance listener callback"), new Max());
Measurable numParts = (config, now) -> subscriptions.numAssignedPartitions();
metrics.addMetric(metrics.metricName("assigned-partitions",
this.metricGrpName,
"The number of partitions currently assigned to this consumer"), numParts);
}
}
private static class MetadataSnapshot {
private final int version;
private final Map<String, Integer> partitionsPerTopic;
private MetadataSnapshot(SubscriptionState subscription, Cluster cluster, int version) {
Map<String, Integer> partitionsPerTopic = new HashMap<>();
for (String topic : subscription.metadataTopics()) {
Integer numPartitions = cluster.partitionCountForTopic(topic);
if (numPartitions != null)
partitionsPerTopic.put(topic, numPartitions);
}
this.partitionsPerTopic = partitionsPerTopic;
this.version = version;
}
boolean matches(MetadataSnapshot other) {
return version == other.version || partitionsPerTopic.equals(other.partitionsPerTopic);
}
@Override
public String toString() {
return "(version" + version + ": " + partitionsPerTopic + ")";
}
}
private static class OffsetCommitCompletion {
private final OffsetCommitCallback callback;
private final Map<TopicPartition, OffsetAndMetadata> offsets;
private final Exception exception;
private OffsetCommitCompletion(OffsetCommitCallback callback, Map<TopicPartition, OffsetAndMetadata> offsets, Exception exception) {
this.callback = callback;
this.offsets = offsets;
this.exception = exception;
}
public void invoke() {
if (callback != null)
callback.onComplete(offsets, exception);
}
}
/* test-only classes below */
RebalanceProtocol getProtocol() {
return protocol;
}
boolean poll(Timer timer) {
return poll(timer, true);
}
}
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