cadonna commented on code in PR #18551: URL: https://github.com/apache/kafka/pull/18551#discussion_r1933839618
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/StreamsMembershipManager.java: ########## @@ -0,0 +1,1009 @@ +/* + * 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 org.apache.kafka.clients.consumer.internals.events.StreamsOnAllTasksLostCallbackCompletedEvent; +import org.apache.kafka.clients.consumer.internals.events.StreamsOnTasksAssignedCallbackCompletedEvent; +import org.apache.kafka.clients.consumer.internals.events.StreamsOnTasksRevokedCallbackCompletedEvent; +import org.apache.kafka.clients.consumer.internals.metrics.ConsumerRebalanceMetricsManager; +import org.apache.kafka.clients.consumer.internals.metrics.RebalanceMetricsManager; +import org.apache.kafka.common.KafkaException; +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.message.StreamsGroupHeartbeatResponseData; +import org.apache.kafka.common.metrics.Metrics; +import org.apache.kafka.common.protocol.Errors; +import org.apache.kafka.common.requests.StreamsGroupHeartbeatRequest; +import org.apache.kafka.common.requests.StreamsGroupHeartbeatResponse; +import org.apache.kafka.common.utils.LogContext; +import org.apache.kafka.common.utils.Time; + +import org.slf4j.Logger; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Optional; +import java.util.SortedSet; +import java.util.TreeSet; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * Tracks state the state of a single member in relationship to a group: + * <p/> + * Responsible for: + * <ul> + * <li>Keeping member state</li> + * <li>Keeping assignment for the member</li> + * <li>Computing assignment for the group if the member is required to do so</li> + * <li>Calling the assignment and revocation callbacks on the Streams client</li> + * </ul> + */ +public class StreamsMembershipManager implements RequestManager { + + /** + * A data structure to represent the current task assignment, and current target task assignment of a member in a + * streams group. + * <p/> + * Besides the assigned tasks, it contains a local epoch that is bumped whenever the assignment changes, to ensure + * that two assignments with the same tasks but different local epochs are not considered equal. + */ + private static class LocalAssignment { + public static final long NONE_EPOCH = -1; + public static final LocalAssignment NONE = new LocalAssignment( + NONE_EPOCH, + Collections.emptyMap(), + Collections.emptyMap(), + Collections.emptyMap() + ); + + public final long localEpoch; + public final Map<String, SortedSet<Integer>> activeTasks; + public final Map<String, SortedSet<Integer>> standbyTasks; + public final Map<String, SortedSet<Integer>> warmupTasks; + + public LocalAssignment(final long localEpoch, + final Map<String, SortedSet<Integer>> activeTasks, + final Map<String, SortedSet<Integer>> standbyTasks, + final Map<String, SortedSet<Integer>> warmupTasks) { + this.localEpoch = localEpoch; + this.activeTasks = activeTasks; + this.standbyTasks = standbyTasks; + this.warmupTasks = warmupTasks; + if (localEpoch == NONE_EPOCH && + (!activeTasks.isEmpty() || !standbyTasks.isEmpty() || !warmupTasks.isEmpty())) { + throw new IllegalArgumentException("Local epoch must be set if tasks are assigned."); + } + } + + Optional<LocalAssignment> updateWith(final Map<String, SortedSet<Integer>> activeTasks, + final Map<String, SortedSet<Integer>> standbyTasks, + final Map<String, SortedSet<Integer>> warmupTasks) { + if (localEpoch != NONE_EPOCH) { + if (activeTasks.equals(this.activeTasks) && + standbyTasks.equals(this.standbyTasks) && + warmupTasks.equals(this.warmupTasks)) { + + return Optional.empty(); + } + } + + long nextLocalEpoch = localEpoch + 1; + return Optional.of(new LocalAssignment(nextLocalEpoch, activeTasks, standbyTasks, warmupTasks)); + } + + @Override + public String toString() { + return "LocalAssignment{" + + "localEpoch=" + localEpoch + + ", activeTasks=" + activeTasks + + ", standbyTasks=" + standbyTasks + + ", warmupTasks=" + warmupTasks + + '}'; + } + + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + LocalAssignment that = (LocalAssignment) o; + return localEpoch == that.localEpoch && + Objects.equals(activeTasks, that.activeTasks) && + Objects.equals(standbyTasks, that.standbyTasks) && + Objects.equals(warmupTasks, that.warmupTasks); + } + + @Override + public int hashCode() { + return Objects.hash(localEpoch, activeTasks, standbyTasks, warmupTasks); + } + } + + static final Utils.TopicPartitionComparator TOPIC_PARTITION_COMPARATOR = new Utils.TopicPartitionComparator(); + + private final Logger log; + + private final StreamsRebalanceEventsProcessor streamsRebalanceEventsProcessor; + + private final StreamsRebalanceData streamsRebalanceData; + + private final SubscriptionState subscriptionState; + + private MemberState state; + + private final String groupId; + + private final String memberId = Uuid.randomUuid().toString(); + + private final Optional<String> groupInstanceId = Optional.empty(); + + private int memberEpoch = 0; + + private Optional<CompletableFuture<Void>> leaveGroupInProgress = Optional.empty(); + + private CompletableFuture<Void> staleMemberAssignmentRelease; + + private boolean reconciliationInProgress; + + private boolean rejoinedWhileReconciliationInProgress; + + private final List<MemberStateListener> stateUpdatesListeners = new ArrayList<>(); + + private LocalAssignment targetAssignment = LocalAssignment.NONE; + + private LocalAssignment currentAssignment = LocalAssignment.NONE; + + private final AtomicBoolean subscriptionUpdated = new AtomicBoolean(false); + + private final RebalanceMetricsManager metricsManager; + + private final Time time; + + private boolean isPollTimerExpired; + + /** + * Constructs the Streams membership manager. + * + * @param groupId The ID of the group. + * @param streamsRebalanceEventsProcessor The processor that handles Streams rebalance events like requests for + * invocation of assignment/revocation callbacks. + * @param streamsRebalanceData Data needed to participate in the Streams rebalance protocol. + * @param subscriptionState The subscription state of the member. + * @param logContext The log context. + * @param time The time. + * @param metrics The metrics. + */ + public StreamsMembershipManager(final String groupId, + final StreamsRebalanceEventsProcessor streamsRebalanceEventsProcessor, + final StreamsRebalanceData streamsRebalanceData, + final SubscriptionState subscriptionState, + final LogContext logContext, + final Time time, + final Metrics metrics) { + log = logContext.logger(StreamsMembershipManager.class); + this.state = MemberState.UNSUBSCRIBED; + this.groupId = groupId; + this.streamsRebalanceEventsProcessor = streamsRebalanceEventsProcessor; + this.streamsRebalanceData = streamsRebalanceData; + this.subscriptionState = subscriptionState; + metricsManager = new ConsumerRebalanceMetricsManager(metrics); + this.time = time; + } + + public String groupId() { + return groupId; + } + + public String memberId() { + return memberId; + } + + public Optional<String> groupInstanceId() { + return groupInstanceId; + } + + public int memberEpoch() { + return memberEpoch; + } + + public MemberState state() { + return state; + } + + public boolean isLeavingGroup() { + MemberState state = state(); + return state == MemberState.PREPARE_LEAVING || state == MemberState.LEAVING; + } + + private boolean isNotInGroup() { + MemberState state = state(); + return state == MemberState.UNSUBSCRIBED || + state == MemberState.FENCED || + state == MemberState.FATAL || + state == MemberState.STALE; + } + + public void registerStateListener(MemberStateListener listener) { + stateUpdatesListeners.add(Objects.requireNonNull(listener, "State updates listener cannot be null")); + } + + void notifyEpochChange(Optional<Integer> epoch) { + stateUpdatesListeners.forEach(stateListener -> stateListener.onMemberEpochUpdated(epoch, memberId)); + } + + private void transitionToJoining() { + if (state == MemberState.FATAL) { + log.warn("No action taken to join the group with the updated subscription because " + + "the member is in FATAL state"); + return; + } + if (reconciliationInProgress) { + rejoinedWhileReconciliationInProgress = true; + } + resetEpoch(); + transitionTo(MemberState.JOINING); + clearCurrentTaskAssignment(); + } + + private void transitionToSendingLeaveGroup(boolean dueToExpiredPollTimer) { + if (state == MemberState.FATAL) { + log.warn("Member {} with epoch {} won't send leave group request because it is in " + + "FATAL state", memberId, memberEpoch); + return; + } + if (state == MemberState.UNSUBSCRIBED) { + log.warn("Member {} won't send leave group request because it is already out of the group.", + memberId); + return; + } + + if (dueToExpiredPollTimer) { + isPollTimerExpired = true; + // Briefly transition through prepare leaving. The member does not have to release + // any assignment before sending the leave group given that is stale. It will invoke + // onTaskAssignment with empty assignment after sending the leave group on the STALE state. + transitionTo(MemberState.PREPARE_LEAVING); + } + finalizeLeaving(); + transitionTo(MemberState.LEAVING); + } + + private void finalizeLeaving() { + updateMemberEpoch(StreamsGroupHeartbeatRequest.LEAVE_GROUP_MEMBER_EPOCH); + clearCurrentTaskAssignment(); + } + + private void transitionToStale() { + transitionTo(MemberState.STALE); + + final CompletableFuture<Void> onAllTasksLostCallbackExecution = + streamsRebalanceEventsProcessor.requestOnAllTasksLostCallbackInvocation(); + staleMemberAssignmentRelease = onAllTasksLostCallbackExecution.whenComplete((result, error) -> { + if (error != null) { + log.error("Task revocation callback invocation failed " + + "after member left group due to expired poll timer.", error); + } + clearTaskAndPartitionAssignment(); + log.debug("Member {} sent leave group heartbeat and released its assignment. It will remain " + + "in {} state until the poll timer is reset, and it will then rejoin the group", + memberId, MemberState.STALE); + }); + } + + public void transitionToFatal() { + MemberState previousState = state; + transitionTo(MemberState.FATAL); + log.error("Member {} with epoch {} transitioned to fatal state", memberId, memberEpoch); + notifyEpochChange(Optional.empty()); + + if (previousState == MemberState.UNSUBSCRIBED) { + log.debug("Member {} with epoch {} got fatal error from the broker but it already " + + "left the group, so onTaskAssignment callback won't be triggered.", memberId, memberEpoch); + return; + } + + if (previousState == MemberState.LEAVING || previousState == MemberState.PREPARE_LEAVING) { + log.info("Member {} with epoch {} was leaving the group with state {} when it got a " + + "fatal error from the broker. It will discard the ongoing leave and remain in " + + "fatal state.", memberId, memberEpoch, previousState); + maybeCompleteLeaveInProgress(); + return; + } + + CompletableFuture<Void> onAllTasksLostCallbackExecuted = streamsRebalanceEventsProcessor.requestOnAllTasksLostCallbackInvocation(); + onAllTasksLostCallbackExecuted.whenComplete((result, error) -> { + if (error != null) { + log.error("onTaskAssignment callback invocation failed while releasing assignment" + + "after member failed with fatal error.", error); + } + clearTaskAndPartitionAssignment(); + }); + } + + public void transitionToUnsubscribeIfLeaving() { + if (state == MemberState.LEAVING) { + log.warn("Heartbeat to leave group cannot be sent (most probably due to coordinator " + + "not known/available). Member {} with epoch {} will transition to {}.", + memberId, memberEpoch, MemberState.UNSUBSCRIBED); + transitionTo(MemberState.UNSUBSCRIBED); + maybeCompleteLeaveInProgress(); + } + } + + private void transitionTo(MemberState nextState) { + if (!state.equals(nextState) && !nextState.getPreviousValidStates().contains(state)) { + throw new IllegalStateException(String.format("Invalid state transition from %s to %s", + state, nextState)); + } + + if (isCompletingRebalance(state, nextState)) { + metricsManager.recordRebalanceEnded(time.milliseconds()); + } + if (isStartingRebalance(state, nextState)) { + metricsManager.recordRebalanceStarted(time.milliseconds()); + } + + log.info("Member {} with epoch {} transitioned from {} to {}.", memberId, memberEpoch, state, nextState); + this.state = nextState; + } + + private static boolean isCompletingRebalance(MemberState currentState, MemberState nextState) { + return currentState == MemberState.RECONCILING && + (nextState == MemberState.STABLE || nextState == MemberState.ACKNOWLEDGING); + } + + private static boolean isStartingRebalance(MemberState currentState, MemberState nextState) { + return currentState != MemberState.RECONCILING && nextState == MemberState.RECONCILING; + } + + private void resetEpoch() { + updateMemberEpoch(StreamsGroupHeartbeatRequest.JOIN_GROUP_MEMBER_EPOCH); + } + + private void updateMemberEpoch(int newEpoch) { + boolean newEpochReceived = this.memberEpoch != newEpoch; + this.memberEpoch = newEpoch; + if (newEpochReceived) { + if (memberEpoch > 0) { + notifyEpochChange(Optional.of(memberEpoch)); + } else { + notifyEpochChange(Optional.empty()); + } + } + } + + private void clearCurrentTaskAssignment() { + currentAssignment = LocalAssignment.NONE; + } + + private void clearTaskAndPartitionAssignment() { + subscriptionState.assignFromSubscribed(Collections.emptySet()); + currentAssignment = LocalAssignment.NONE; + targetAssignment = LocalAssignment.NONE; + } + + public boolean shouldSkipHeartbeat() { + return isNotInGroup(); + } + + public boolean shouldHeartbeatNow() { + MemberState state = state(); + return state == MemberState.ACKNOWLEDGING || state == MemberState.LEAVING || state == MemberState.JOINING; + } + + public void onSubscriptionUpdated() { + subscriptionUpdated.compareAndSet(false, true); + } + + public void onConsumerPoll() { + if (subscriptionUpdated.compareAndSet(true, false) && state == MemberState.UNSUBSCRIBED) { + transitionToJoining(); + } + } + + public void onHeartbeatRequestGenerated() { + MemberState state = state(); + if (state == MemberState.ACKNOWLEDGING) { + if (targetAssignmentReconciled()) { + transitionTo(MemberState.STABLE); + } else { + log.debug("Member {} with epoch {} transitioned to {} after a heartbeat was sent " + + "to ack a previous reconciliation. New assignments are ready to " + + "be reconciled.", memberId, memberEpoch, MemberState.RECONCILING); + transitionTo(MemberState.RECONCILING); + } + } else if (state == MemberState.LEAVING) { + if (isPollTimerExpired) { + log.debug("Member {} with epoch {} generated the heartbeat to leave due to expired poll timer. It will " + + "remain stale (no heartbeat) until it rejoins the group on the next consumer " + + "poll.", memberId, memberEpoch); + transitionToStale(); + } else { + log.debug("Member {} with epoch {} generated the heartbeat to leave the group.", memberId, memberEpoch); + transitionTo(MemberState.UNSUBSCRIBED); + } + } + } + + public void onHeartbeatSuccess(StreamsGroupHeartbeatResponse response) { + StreamsGroupHeartbeatResponseData responseData = response.data(); + throwIfUnexpectedError(responseData); + if (state == MemberState.LEAVING) { + log.debug("Ignoring heartbeat response received from broker. Member {} with epoch {} is " + + "already leaving the group.", memberId, memberEpoch); + return; + } + if (state == MemberState.UNSUBSCRIBED && maybeCompleteLeaveInProgress()) { + log.debug("Member {} with epoch {} received a successful response to the heartbeat " + + "to leave the group and completed the leave operation. ", memberId, memberEpoch); + return; + } + if (isNotInGroup()) { + log.debug("Ignoring heartbeat response received from broker. Member {} is in {} state" + + " so it's not a member of the group. ", memberId, state); + return; + } + + updateMemberEpoch(responseData.memberEpoch()); + + final List<StreamsGroupHeartbeatResponseData.TaskIds> activeTasks = responseData.activeTasks(); + final List<StreamsGroupHeartbeatResponseData.TaskIds> standbyTasks = responseData.standbyTasks(); + final List<StreamsGroupHeartbeatResponseData.TaskIds> warmupTasks = responseData.warmupTasks(); + + if (activeTasks != null && standbyTasks != null && warmupTasks != null) { + + if (!state.canHandleNewAssignment()) { + log.debug("Ignoring new assignment: active tasks {}, standby tasks {}, and warm-up tasks {} received " + + "from server because member is in {} state.", + activeTasks, standbyTasks, warmupTasks, state); + return; + } + + processAssignmentReceived( + toTasksAssignment(activeTasks), + toTasksAssignment(standbyTasks), + toTasksAssignment(warmupTasks) + ); + } else { + if (responseData.activeTasks() != null || + responseData.standbyTasks() != null || + responseData.warmupTasks() != null) { + + throw new IllegalStateException("Invalid response data, task collections must be all null or all non-null: " + + responseData); + } + } + } + + public void onHeartbeatFailure(boolean retriable) { + if (!retriable) { + metricsManager.maybeRecordRebalanceFailed(); + } + // The leave group request is sent out once (not retried), so we should complete the leave + // operation once the request completes, regardless of the response. + if (state == MemberState.UNSUBSCRIBED && maybeCompleteLeaveInProgress()) { + log.warn("Member {} with epoch {} received a failed response to the heartbeat to " + + "leave the group and completed the leave operation. ", memberId, memberEpoch); + } + } + + public void onPollTimerExpired() { + transitionToSendingLeaveGroup(true); + } + + public void onFenced() { + if (state == MemberState.PREPARE_LEAVING) { + log.info("Member {} with epoch {} got fenced but it is already preparing to leave " + + "the group, so it will stop sending heartbeat and won't attempt to send the " + + "leave request or rejoin.", memberId, memberEpoch); + finalizeLeaving(); + transitionTo(MemberState.UNSUBSCRIBED); + maybeCompleteLeaveInProgress(); + return; + } + + if (state == MemberState.LEAVING) { + log.debug("Member {} with epoch {} got fenced before sending leave group heartbeat. " + + "It will not send the leave request and won't attempt to rejoin.", memberId, memberEpoch); + transitionTo(MemberState.UNSUBSCRIBED); + maybeCompleteLeaveInProgress(); + return; + } + if (state == MemberState.UNSUBSCRIBED) { + log.debug("Member {} with epoch {} got fenced but it already left the group, so it " + + "won't attempt to rejoin.", memberId, memberEpoch); + return; + } + transitionTo(MemberState.FENCED); + resetEpoch(); + log.debug("Member {} with epoch {} transitioned to {} state. It will release its " + + "assignment and rejoin the group.", memberId, memberEpoch, MemberState.FENCED); + + CompletableFuture<Void> callbackResult = streamsRebalanceEventsProcessor.requestOnAllTasksLostCallbackInvocation(); + callbackResult.whenComplete((result, error) -> { + if (error != null) { + log.error("onAllTasksLost callback invocation failed while releasing assignment" + + " after member got fenced. Member will rejoin the group anyways.", error); + } + clearTaskAndPartitionAssignment(); + if (state == MemberState.FENCED) { + transitionToJoining(); + } else { + log.debug("Fenced member onAllTasksLost callback completed but the state has " + + "already changed to {}, so the member won't rejoin the group", state); + } + }); + } + + private void throwIfUnexpectedError(StreamsGroupHeartbeatResponseData responseData) { + if (responseData.errorCode() != Errors.NONE.code()) { + String errorMessage = String.format( + "Unexpected error in Heartbeat response. Expected no error, but received: %s with message: '%s'", + Errors.forCode(responseData.errorCode()), responseData.errorMessage() + ); + throw new IllegalArgumentException(errorMessage); + } + } + + public void maybeRejoinStaleMember() { Review Comment: Done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. 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