rkhachatryan commented on code in PR #19550: URL: https://github.com/apache/flink/pull/19550#discussion_r859630417
########## flink-dstl/flink-dstl-dfs/src/main/java/org/apache/flink/changelog/fs/ChangelogRegistryImpl.java: ########## @@ -0,0 +1,91 @@ +/* + * 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.flink.changelog.fs; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.runtime.state.PhysicalStateHandleID; +import org.apache.flink.runtime.state.StreamStateHandle; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.concurrent.ThreadSafe; + +import java.util.Map; +import java.util.Set; +import java.util.UUID; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.CopyOnWriteArraySet; +import java.util.concurrent.Executor; + +@Internal +@ThreadSafe +class ChangelogRegistryImpl implements ChangelogRegistry { + private static final Logger LOG = LoggerFactory.getLogger(ChangelogRegistryImpl.class); + + private final Map<PhysicalStateHandleID, Set<UUID>> entries = new ConcurrentHashMap<>(); + private final Executor executor; + + public ChangelogRegistryImpl(Executor executor) { + this.executor = executor; + } + + @Override + public void startTracking(StreamStateHandle handle, Set<UUID> backendIDs) { + LOG.debug( + "start tracking state, key: {}, state: {}", + handle.getStreamStateHandleID(), + handle); + entries.put(handle.getStreamStateHandleID(), new CopyOnWriteArraySet<>(backendIDs)); + } + + @Override + public void stopTracking(StreamStateHandle handle) { + LOG.debug( + "stop tracking state, key: {}, state: {}", handle.getStreamStateHandleID(), handle); + entries.remove(handle.getStreamStateHandleID()); + } + + @Override + public void notUsed(StreamStateHandle handle, UUID backendId) { Review Comment: > we then call changelogTruncateHelper.materialized(upTo) after materialization finished. > Thus, we would discard change logs with upTo as 100 Let's assume there is some valid or pending checkpoint that uses sqn <= 100. But JM completion notification was lost, and therefore `stopTracking` was not called. But if that checkpoint is valid/pending, it couldn't be subsumed (nor any newer checkpoint). Therefore, `ChangelogTruncateHelper.subsumedUpTo` hasn't been advanced yet. Therefore, discard will not happen at this point because `ChangelogTruncateHelper` truncates the logs up to `min(materializedUpTo, subsumedUpTo)`. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
