joshua2519 commented on code in PR #21261: URL: https://github.com/apache/kafka/pull/21261#discussion_r2684655217
########## server/src/main/java/org/apache/kafka/server/NodeToControllerRequestThread.java: ########## @@ -0,0 +1,202 @@ +/* + * 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.server; + +import org.apache.kafka.clients.ClientResponse; +import org.apache.kafka.clients.KafkaClient; +import org.apache.kafka.clients.ManualMetadataUpdater; +import org.apache.kafka.common.Node; +import org.apache.kafka.common.config.AbstractConfig; +import org.apache.kafka.common.protocol.Errors; +import org.apache.kafka.common.utils.Time; +import org.apache.kafka.server.config.ReplicationConfigs; +import org.apache.kafka.server.util.InterBrokerSendThread; +import org.apache.kafka.server.util.RequestAndCompletionHandler; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Collection; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.Optional; +import java.util.concurrent.LinkedBlockingDeque; +import java.util.concurrent.atomic.AtomicReference; + +/** + * Background thread that manages to send requests to the active controller. + * <p> + * Maintains a queue of pending requests and handles automatic retries on failures, + * controller failover, and timeout detection. Requests are re-queued when the controller + * changes or connections are lost. + */ +public class NodeToControllerRequestThread extends InterBrokerSendThread { + private static final Logger log = LoggerFactory.getLogger(NodeToControllerRequestThread.class); + + private final LinkedBlockingDeque<NodeToControllerQueueItem> requestQueue = new LinkedBlockingDeque<>(); + private final AtomicReference<Node> activeController = new AtomicReference<>(null); + + + private final Time time; + private final long retryTimeoutMs; + private final ControllerNodeProvider controllerNodeProvider; + private final ManualMetadataUpdater metadataUpdater; + + // Used for testing + volatile boolean started = false; + public void setStarted(boolean started) { + this.started = started; + } + + public NodeToControllerRequestThread(KafkaClient initialNetworkClient, + ManualMetadataUpdater metadataUpdater, + ControllerNodeProvider controllerNodeProvider, + AbstractConfig config, + Time time, + String threadName, + Long retryTimeoutMs) { + super(threadName, initialNetworkClient, Math.min(Integer.MAX_VALUE, (int) Math.min(config.getInt(ReplicationConfigs.CONTROLLER_SOCKET_TIMEOUT_MS_CONFIG), retryTimeoutMs)), time, false); + this.time = time; + this.controllerNodeProvider = controllerNodeProvider; + this.metadataUpdater = metadataUpdater; + this.retryTimeoutMs = retryTimeoutMs; + } + + public Optional<Node> activeControllerAddress() { + return Optional.ofNullable(activeController.get()); + } + + private void updateControllerAddress(Node newActiveController) { + activeController.set(newActiveController); + } + + public void enqueue(NodeToControllerQueueItem request) { + if (!started) { + throw new IllegalStateException("Cannot enqueue a request if the request thread is not running"); + } + requestQueue.add(request); + if (activeControllerAddress().isPresent()) { + wakeup(); + } + } + + public int queueSize() { + return requestQueue.size(); + } + + @Override + public Collection<RequestAndCompletionHandler> generateRequests() { + final long currentTimeMs = time.milliseconds(); + final Iterator<NodeToControllerQueueItem> requestIter = requestQueue.iterator(); + while (requestIter.hasNext()) { + var request = requestIter.next(); + if (currentTimeMs - request.createdTimeMs() >= retryTimeoutMs) { + requestIter.remove(); + request.callback().onTimeout(); + } else { + Optional<Node> controllerAddress = activeControllerAddress(); + if (controllerAddress.isPresent()) { + requestIter.remove(); + return Collections.singletonList(new RequestAndCompletionHandler( + time.milliseconds(), + controllerAddress.get(), + request.request(), + response -> handleResponse(request, response) + )); + } + } + } + + return Collections.emptyList(); + } + + void handleResponse(NodeToControllerQueueItem queueItem, ClientResponse response) { + log.debug("Request {} received {}", queueItem.request(), response); + if (response.authenticationException() != null) { + log.error("Request {} failed due to authentication error with controller. Disconnecting the " + + "connection to the stale controller {}", + queueItem.request(), activeControllerAddress().map(Node::idString).orElse("null"), + response.authenticationException() + ); + maybeDisconnectAndUpdateController(); + queueItem.callback().onComplete(response); + } else if (response.versionMismatch() != null) { + log.error("Request {} failed due to unsupported version error", queueItem.request(), + response.versionMismatch()); + queueItem.callback().onComplete(response); + } else if (response.wasDisconnected()) { + updateControllerAddress(null); + requestQueue.addFirst(queueItem); + } else if (response.responseBody().errorCounts().containsKey(Errors.NOT_CONTROLLER)) { + log.debug("Request {} received NOT_CONTROLLER exception. Disconnecting the " + + "connection to the stale controller {}", + queueItem.request(), + activeControllerAddress().map(Node::idString).orElse("null")); + maybeDisconnectAndUpdateController(); + try { + requestQueue.putFirst(queueItem); 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
