zhijiangW commented on a change in pull request #11515: [FLINK-16744][task] implement channel state persistence for unaligned checkpoints URL: https://github.com/apache/flink/pull/11515#discussion_r404932029
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/checkpoint/channel/ChannelStateCheckpointWriter.java ########## @@ -0,0 +1,203 @@ +/* + * 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.runtime.checkpoint.channel; + +import org.apache.flink.runtime.checkpoint.channel.ChannelStateWriter.ChannelStateWriteResult; +import org.apache.flink.runtime.io.network.buffer.Buffer; +import org.apache.flink.runtime.state.AbstractChannelStateHandle; +import org.apache.flink.runtime.state.CheckpointStreamFactory; +import org.apache.flink.runtime.state.CheckpointStreamFactory.CheckpointStateOutputStream; +import org.apache.flink.runtime.state.InputChannelStateHandle; +import org.apache.flink.runtime.state.ResultSubpartitionStateHandle; +import org.apache.flink.runtime.state.StreamStateHandle; +import org.apache.flink.util.Preconditions; +import org.apache.flink.util.function.RunnableWithException; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.concurrent.NotThreadSafe; + +import java.io.DataOutputStream; +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.CompletableFuture; +import java.util.function.BiFunction; + +import static org.apache.flink.runtime.state.CheckpointedStateScope.EXCLUSIVE; +import static org.apache.flink.util.Preconditions.checkNotNull; +import static org.apache.flink.util.Preconditions.checkState; + +/** + * Writes channel state for a specific checkpoint-subtask-attempt triple. + */ +@NotThreadSafe +class ChannelStateCheckpointWriter { + private static final Logger LOG = LoggerFactory.getLogger(ChannelStateCheckpointWriter.class); + + private final DataOutputStream dataStream; + private final CheckpointStateOutputStream checkpointStream; + private final ChannelStateWriteResult result; + private final Map<InputChannelInfo, List<Long>> inputChannelOffsets = new HashMap<>(); + private final Map<ResultSubpartitionInfo, List<Long>> resultSubpartitionOffsets = new HashMap<>(); + private final ChannelStateSerializer serializer; + private final long checkpointId; + private boolean allInputsReceived = false; + private boolean allOutputsReceived = false; + private final RunnableWithException onComplete; + + ChannelStateCheckpointWriter( + CheckpointStartRequest startCheckpointItem, + CheckpointStreamFactory streamFactory, + ChannelStateSerializer serializer, + RunnableWithException onComplete) throws Exception { + this( + startCheckpointItem.getCheckpointId(), + startCheckpointItem.getTargetResult(), + streamFactory.createCheckpointStateOutputStream(EXCLUSIVE), + serializer, + onComplete); + } + + ChannelStateCheckpointWriter( + long checkpointId, + ChannelStateWriteResult result, + CheckpointStateOutputStream stream, + ChannelStateSerializer serializer, + RunnableWithException onComplete) throws Exception { + this(checkpointId, result, serializer, onComplete, stream, new DataOutputStream(stream)); + } + + ChannelStateCheckpointWriter( + long checkpointId, + ChannelStateWriteResult result, + ChannelStateSerializer serializer, + RunnableWithException onComplete, + CheckpointStateOutputStream checkpointStateOutputStream, + DataOutputStream dataStream) throws Exception { + this.checkpointId = checkpointId; + this.result = checkNotNull(result); + this.checkpointStream = checkNotNull(checkpointStateOutputStream); + this.serializer = checkNotNull(serializer); + this.dataStream = checkNotNull(dataStream); + this.onComplete = checkNotNull(onComplete); + runWithChecks(() -> serializer.writeHeader(dataStream)); + } + + void writeInput(InputChannelInfo info, Buffer... flinkBuffers) throws Exception { + write(inputChannelOffsets, info, flinkBuffers, !allInputsReceived); + } + + void writeOutput(ResultSubpartitionInfo info, Buffer[] flinkBuffers) throws Exception { + write(resultSubpartitionOffsets, info, flinkBuffers, !allOutputsReceived); + } + + private <K> void write(Map<K, List<Long>> offsets, K key, Buffer[] flinkBuffers, boolean precondition) throws Exception { + try { + if (result.isDone()) { + return; + } + runWithChecks(() -> { + checkState(precondition); + offsets + .computeIfAbsent(key, unused -> new ArrayList<>()) + .add(checkpointStream.getPos()); + serializer.writeData(dataStream, flinkBuffers); + }); + } finally { + for (Buffer flinkBuffer : flinkBuffers) { + flinkBuffer.recycleBuffer(); + } + } + } + + void completeInput() throws Exception { + LOG.debug("complete input, output completed: {}", allOutputsReceived); + complete(!allInputsReceived, () -> allInputsReceived = true); + } + + void completeOutput() throws Exception { + LOG.debug("complete output, input completed: {}", allInputsReceived); + complete(!allOutputsReceived, () -> allOutputsReceived = true); + } + + private void complete(boolean precondition, RunnableWithException complete) throws Exception { + if (result.isDone()) { + // likely after abort - only need to set the flag run onComplete callback + doComplete(precondition, complete, onComplete); + } else { + runWithChecks(() -> doComplete(precondition, complete, onComplete, this::finishWriteAndResult)); + } + } + + private void finishWriteAndResult() throws IOException { + dataStream.flush(); + StreamStateHandle underlying = checkpointStream.closeAndGetHandle(); + complete( + result.inputChannelStateHandles, + inputChannelOffsets, + (chan, offsets) -> new InputChannelStateHandle(chan, underlying, offsets)); + complete( + result.resultSubpartitionStateHandles, + resultSubpartitionOffsets, + (chan, offsets) -> new ResultSubpartitionStateHandle(chan, underlying, offsets)); + } + + private void doComplete(boolean precondition, RunnableWithException complete, RunnableWithException... callbacks) throws Exception { + Preconditions.checkArgument(precondition); + complete.run(); + if (allInputsReceived && allOutputsReceived) { + for (RunnableWithException callback : callbacks) { + callback.run(); + } + } + } + + private <I, H extends AbstractChannelStateHandle<I>> void complete( + CompletableFuture<Collection<H>> future, + Map<I, List<Long>> offsets, + BiFunction<I, List<Long>, H> buildHandle) { + final Collection<H> handles = new ArrayList<>(); + for (Map.Entry<I, List<Long>> e : offsets.entrySet()) { + handles.add(buildHandle.apply(e.getKey(), e.getValue())); + } + future.complete(handles); + LOG.debug("channel state write completed, checkpointId: {}, handles: {}", checkpointId, handles); + } + + private void runWithChecks(RunnableWithException r) throws Exception { + try { + checkState(!result.isDone(), "result is already completed", result); + r.run(); + } catch (Exception e) { + fail(e); + throw e; + } + } + + public void fail(Throwable e) throws Exception { + result.fail(e); + checkpointStream.close(); + dataStream.close(); Review comment: Are there any problems if `checkpointStream.close()` causes exception to not execute the below `dataStream.close()`? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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