dajac commented on code in PR #14323: URL: https://github.com/apache/kafka/pull/14323#discussion_r1321316433
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/MembershipManagerImpl.java: ########## @@ -0,0 +1,167 @@ +/* + * 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.common.message.ConsumerGroupHeartbeatResponseData; +import org.apache.kafka.common.protocol.Errors; + +import java.util.ArrayList; +import java.util.List; +import java.util.Optional; + +/** + * Membership manager that maintains group membership for a single member following the new + * consumer group protocol. + * <p/> + * This keeps membership state and assignment updated in-memory, based on the heartbeat responses + * the member receives. It is also responsible for computing assignment for the group based on + * the metadata, if the member has been selected by the broker to do so. + */ +public class MembershipManagerImpl implements MembershipManager { + + private final String groupId; + private Optional<String> groupInstanceId; + private String memberId; + private int memberEpoch; + private MemberState state; + private AssignorSelection assignorSelection; + + /** + * Assignment that the member received from the server and successfully processed + */ + private ConsumerGroupHeartbeatResponseData.Assignment currentAssignment; + + /** + * List of assignments that the member received from the server but hasn't processed yet + */ + private final List<ConsumerGroupHeartbeatResponseData.Assignment> targetAssignments; Review Comment: I think that we need to think a little more about how we will handle this. My concern is that the server side may start timers based on the `nextTargetAssignment` but the client won't look into it before it finishes the reconciliation to the `targetAssignment`. For instance, imagine the following scenario. * Current assignment is A and B; * Server asks to revoke A and starts the rebalance timer (5 minutes by default); * Client starts the revocation of A. This can take a while; * Server asks to revoke B and restarts the rebalance timer; * Client still waits on the revocation of A to complete. When completed, it starts the revocation of B. In this scenario, if the revocation of A and B takes more than 5 minutes altogether, the member will be kicked out from the consumer group. The server does not know that the consumer is blocked on the revocation of A. Do we really need to wait until A is fully revoked before we can start the process to revoke B? -- 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
