ndimiduk commented on code in PR #7172: URL: https://github.com/apache/hbase/pull/7172#discussion_r2273818445
########## hbase-server/src/main/java/org/apache/hadoop/hbase/replication/WALEntryFilterBase.java: ########## @@ -0,0 +1,66 @@ +/* + * 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.hadoop.hbase.replication; + +import org.apache.hadoop.hbase.HBaseInterfaceAudience; +import org.apache.hadoop.hbase.wal.WAL.Entry; +import org.apache.yetus.audience.InterfaceAudience; + +/** + * Base class for {@link WALEntryFilter}, store the necessary common properties like + * {@link #serial}. + * <p> + * Why need to treat serial replication specially: + * <p> + * Under some special cases, we may filter out some entries but we still need to record the last + * pushed sequence id for these entries. For example, when we setup a bidirection replication A + * <-> B, if we write to both cluster A and cluster B, cluster A will not replicate the + * entries which are replicated from cluster B, which means we may have holes in the replication + * sequence ids. So if the region is closed abnormally, i.e, we do not have a close event for the + * region, and before the closing, we have some entries from cluster B, then the replication from + * cluster A to cluster B will be stuck if we do not record the last pushed sequence id of these + * entries because we will find out that the previous sequence id range will never finish. So we + * need to record the sequence id for these entries so the last pushed sequence id can reach the + * region barrier. + * @see <a href="https://issues.apache.org/jira/browse/HBASE-29463";>HBASE-29463</a> + */ [email protected](HBaseInterfaceAudience.REPLICATION) +public abstract class WALEntryFilterBase implements WALEntryFilter { + + protected boolean serial; + + @Override + public void setSerial(boolean serial) { + this.serial = serial; + } + + /** + * Call this method when you do not need to replicate the entry. + * <p> + * For serial replication, since still need to WALKey for recording progress, we clear all the + * cells of the WALEdit. For normal replication, we just return null. + */ + protected final Entry clearOrNull(Entry entry) { + if (serial) { + entry.getEdit().getCells().clear(); + return entry; + } else { + return null; Review Comment: Bummer. Okay, fair enough. -- 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]
