chia7712 commented on code in PR #23830: URL: https://github.com/apache/kafka/pull/23830#discussion_r4493703441
########## server-common/src/main/java/org/apache/kafka/server/mirror/MirrorPartitionState.java: ########## @@ -0,0 +1,112 @@ +/* + * 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.mirror; + +/** + * Lifecycle states of a mirror partition. + * Values changes require an update to the javadoc of LeaderStateDescription.state(). + */ +public enum MirrorPartitionState { + /** + * Initial state: aligning local log with the source leader's log. + * Triggered when a partition is first added to mirroring or after recovery. + */ + LOG_ALIGNMENT((byte) 0), + + /** + * Local leader epoch is being bumped to match source partition's leader epoch. + * Occurs when the source leader epoch exceeds the local epoch, protecting against + * stale reads and ensuring epoch ordering. + */ + EPOCH_FENCING((byte) 1), + + /** + * Recovering from unclean leader election on the source cluster. + * In this state, offsets are determined by reading the source leader's state, + * then committed via the destination's group coordinator. + */ + ULE_RECOVERY((byte) 2), + + /** + * Actively mirroring data from source to destination. + * The partition is fully initialized and continuously replicating records. + */ + MIRRORING((byte) 3), + + /** + * Pausing mirroring: replication is stopping but will resume. + * Transient state, expected to move to PAUSED. + */ + PAUSING((byte) 4), + + /** + * Paused: replication is halted but can be resumed. + * Useful for temporary maintenance or administrator control. + */ + PAUSED((byte) 5), + + /** + * Stopping mirroring: replication is terminating permanently. + * Transient state, expected to move to STOPPED. + */ + STOPPING((byte) 6), + + /** + * Stopped: mirroring has been permanently terminated. + * The partition will no longer be replicated. + */ + STOPPED((byte) 7), + + /** + * Failed: mirroring encountered an error and cannot proceed. + * The error reason and retry information are stored in the metadata. + * Retryable failures will eventually transition back to LOG_ALIGNMENT. + * Non-retryable failures remain in FAILED state. + */ + FAILED((byte) 8), + + /** + * Unknown state: used when the state cannot be determined or is uninitialized. + */ + UNKNOWN((byte) -1); + + private final byte value; + + MirrorPartitionState(byte value) { + this.value = value; + } + + public byte value() { + return value; + } + + public static MirrorPartitionState fromValue(byte value) { + switch (value) { + case 0: return LOG_ALIGNMENT; Review Comment: We can leverage the switch expression: ```java return switch (value) { case 0 -> LOG_ALIGNMENT; case 1 -> EPOCH_FENCING; case 2 -> ULE_RECOVERY; case 3 -> MIRRORING; case 4 -> PAUSING; case 5 -> PAUSED; case 6 -> STOPPING; case 7 -> STOPPED; case 8 -> FAILED; case -1 -> UNKNOWN; default -> throw new IllegalArgumentException("Illegal mirror state: " + value); }; ``` -- 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]
