hachikuji commented on code in PR #12862: URL: https://github.com/apache/kafka/pull/12862#discussion_r1043785411
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/CoordinatorRequestManager.java: ########## @@ -0,0 +1,289 @@ +/* + * 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.ClientResponse; +import org.apache.kafka.clients.consumer.ConsumerConfig; +import org.apache.kafka.common.Node; +import org.apache.kafka.common.errors.GroupAuthorizationException; +import org.apache.kafka.common.errors.RetriableException; +import org.apache.kafka.common.message.FindCoordinatorRequestData; +import org.apache.kafka.common.message.FindCoordinatorResponseData; +import org.apache.kafka.common.protocol.Errors; +import org.apache.kafka.common.requests.FindCoordinatorRequest; +import org.apache.kafka.common.requests.FindCoordinatorResponse; +import org.apache.kafka.common.utils.ExponentialBackoff; +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.Objects; +import java.util.Optional; + +/** + * Handles the timing of the next FindCoordinatorRequest based on the {@link CoordinatorRequestState}. It checks for: + * 1. If there's an existing coordinator. + * 2. If there is an inflight request + * 3. If the backoff timer has expired + * + * The {@link org.apache.kafka.clients.consumer.internals.NetworkClientDelegate.PollResult} contains either a wait + * timer, or a singleton list of + * {@link org.apache.kafka.clients.consumer.internals.NetworkClientDelegate.UnsentRequest}. + * + * The FindCoordinatorResponse will be handled by the {@link FindCoordinatorRequestHandler} callback, which + * subsequently invokes {@code onResponse} to handle the exceptions and responses. Note that, the coordinator node + * will be marked {@code null} upon receiving a failure. + */ +public class CoordinatorRequestManager implements RequestManager { + + private final Logger log; + private final Time time; + private final ErrorEventHandler errorHandler; + private final long rebalanceTimeoutMs; + private final String groupId; + + private final CoordinatorRequestState coordinatorRequestState; + private long timeMarkedUnknownMs = -1L; // starting logging a warning only after unable to connect for a while + private Node coordinator; + + + public CoordinatorRequestManager(final Time time, + final LogContext logContext, + final ConsumerConfig config, + final ErrorEventHandler errorHandler, + final String groupId, + final long rebalanceTimeoutMs) { + Objects.requireNonNull(groupId); + this.time = time; + this.log = logContext.logger(this.getClass()); + this.errorHandler = errorHandler; + this.groupId = groupId; + this.rebalanceTimeoutMs = rebalanceTimeoutMs; + this.coordinatorRequestState = new CoordinatorRequestState(config); + } + + // Visible for testing + CoordinatorRequestManager(final Time time, + final LogContext logContext, + final ErrorEventHandler errorHandler, + final String groupId, + final long rebalanceTimeoutMs, + final CoordinatorRequestState coordinatorRequestState) { + Objects.requireNonNull(groupId); + this.time = time; + this.log = logContext.logger(this.getClass()); + this.errorHandler = errorHandler; + this.groupId = groupId; + this.rebalanceTimeoutMs = rebalanceTimeoutMs; + this.coordinatorRequestState = coordinatorRequestState; + } + + @Override + public NetworkClientDelegate.PollResult poll(final long currentTimeMs) { + if (this.coordinator != null) { + return new NetworkClientDelegate.PollResult(Long.MAX_VALUE, Collections.emptyList()); + } + + if (coordinatorRequestState.canSendRequest(currentTimeMs)) { + NetworkClientDelegate.UnsentRequest request = makeFindCoordinatorRequest(currentTimeMs); + return new NetworkClientDelegate.PollResult(0, Collections.singletonList(request)); + } + + return new NetworkClientDelegate.PollResult( + coordinatorRequestState.remainingBackoffMs(currentTimeMs), + new ArrayList<>()); + } + + private NetworkClientDelegate.UnsentRequest makeFindCoordinatorRequest(final long currentTimeMs) { + coordinatorRequestState.updateLastSend(currentTimeMs); + FindCoordinatorRequestData data = new FindCoordinatorRequestData() + .setKeyType(FindCoordinatorRequest.CoordinatorType.GROUP.id()) + .setKey(this.groupId); + return NetworkClientDelegate.UnsentRequest.makeUnsentRequest( + new FindCoordinatorRequest.Builder(data), + new FindCoordinatorRequestHandler(), + null); + } + + /** + * Mark the current coordinator null and return the old coordinator. Return an empty Optional + * if the current coordinator is unknown. + * @param cause why the coordinator is marked unknown + * @return Optional coordinator node that can be null. + */ + protected void markCoordinatorUnknown(final String cause, final long currentTimeMs) { + if (this.coordinator != null) { + log.info("Group coordinator {} is unavailable or invalid due to cause: {}. " + + "Rediscovery will be attempted.", this.coordinator, cause); + this.coordinator = null; + timeMarkedUnknownMs = currentTimeMs; + } else { + long durationOfOngoingDisconnect = Math.max(0, currentTimeMs - timeMarkedUnknownMs); + if (durationOfOngoingDisconnect > this.rebalanceTimeoutMs) + log.debug("Consumer has been disconnected from the group coordinator for {}ms", + durationOfOngoingDisconnect); + } + } + + private void onSuccessfulResponse( + final FindCoordinatorResponseData.Coordinator coordinator, + final long currentTimeMS) { + // use MAX_VALUE - node.id as the coordinator id to allow separate connections + // for the coordinator in the underlying network client layer + int coordinatorConnectionId = Integer.MAX_VALUE - coordinator.nodeId(); + + this.coordinator = new Node( + coordinatorConnectionId, + coordinator.host(), + coordinator.port()); + log.info("Discovered group coordinator {}", coordinator); + coordinatorRequestState.reset(); + return; + } + + private void handleFailedCoordinatorResponse( + final Exception exception, + final long currentTimeMs) { + coordinatorRequestState.updateLastFailedAttempt(currentTimeMs); + markCoordinatorUnknown("coordinator unavailable", currentTimeMs); + + if (exception == Errors.GROUP_AUTHORIZATION_FAILED.exception()) { + log.debug("FindCoordinator request failed due to authorization error {}", exception.getMessage()); + errorHandler.handle(GroupAuthorizationException.forGroupId(this.groupId)); + return; + } + + if (exception instanceof RetriableException) { + log.debug("FindCoordinator request failed due to retriable exception", exception); + return; + } + + log.warn("FindCoordinator request failed due to fatal exception", exception); + errorHandler.handle(exception); + } + + public void onResponse(final FindCoordinatorResponse response, final long currentTimeMs, final Throwable t) { + // handle Runtime exception + if (t != null) { + log.error("FindCoordinator request failed due to {}", t.getMessage()); Review Comment: Why don't we call `handleFailedCoordinatorResponse` here? Also, we should get in the habit of including the full stack trace in error messages. -- 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. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
