ableegoldman commented on a change in pull request #11787: URL: https://github.com/apache/kafka/pull/11787#discussion_r815264270
########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/TaskExecutionMetadata.java ########## @@ -0,0 +1,98 @@ +/* + * 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.streams.processor.internals; + +import org.apache.kafka.common.utils.LogContext; +import org.apache.kafka.streams.processor.TaskId; + +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import org.slf4j.Logger; + +import static org.apache.kafka.streams.processor.internals.TopologyMetadata.UNNAMED_TOPOLOGY; + +/** + * Multi-threaded class that tracks the status of active tasks being processed. A single instance of this class is + * shared between all StreamThreads. + */ +public class TaskExecutionMetadata { + private final boolean hasNamedTopologies; + // map of topologies experiencing errors/currently under backoff + private final ConcurrentHashMap<String, NamedTopologyMetadata> topologyNameToErrorMetadata = new ConcurrentHashMap<>(); + + public TaskExecutionMetadata(final Set<String> allTopologyNames) { + this.hasNamedTopologies = !(allTopologyNames.size() == 1 && allTopologyNames.contains(UNNAMED_TOPOLOGY)); + } + + public boolean canProcessTask(final Task task, final long now) { + final String topologyName = task.id().topologyName(); + if (!hasNamedTopologies) { + // TODO implement error handling/backoff for non-named topologies (needs KIP) + return true; + } else { + final NamedTopologyMetadata metadata = topologyNameToErrorMetadata.get(topologyName); + return metadata == null || (metadata.canProcess() && metadata.canProcessTask(task, now)); + } + } + + public void registerTaskError(final Task task, final Throwable t, final long now) { + if (hasNamedTopologies) { + final String topologyName = task.id().topologyName(); + topologyNameToErrorMetadata.computeIfAbsent(topologyName, n -> new NamedTopologyMetadata(topologyName)) + .registerTaskError(task, t, now); + } + } + + class NamedTopologyMetadata { + private final Logger log; + private final Map<TaskId, Long> tasksToErrorTime = new ConcurrentHashMap<>(); + + public NamedTopologyMetadata(final String topologyName) { + final LogContext logContext = new LogContext(String.format("topology-name [%s] ", topologyName)); + this.log = logContext.logger(NamedTopologyMetadata.class); + } + + public boolean canProcess() { + // TODO: during long task backoffs, pause the full topology to avoid it getting out of sync + return true; + } + + public boolean canProcessTask(final Task task, final long now) { + // TODO: implement exponential backoff, for now we just wait 15s + final Long errorTime = tasksToErrorTime.get(task.id()); + if (errorTime == null) { + return true; + } else if (now - errorTime > 15000L) { Review comment: Because it was actually taking the thread 10s to come back up (in the integration test where we overrode `session.timeout` to 10s) before we had https://github.com/apache/kafka/pull/11801 Now with that fix it takes .5 - 4s for the thread to be replaced, so there's no particular reason to have it be 15s. I think it makes sense to lower it to maybe 5s for now, and then when we have the true exponential backoff obviously it can start lower and grow from there. -- 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
