flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From tillrohrmann <...@git.apache.org>
Subject [GitHub] flink pull request #2629: [FLINK-4391] Provide support for asynchronous oper...
Date Mon, 21 Nov 2016 11:32:05 GMT
Github user tillrohrmann commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2629#discussion_r88866589
  
    --- Diff: flink-streaming-java/src/main/java/org/apache/flink/streaming/api/operators/async/AsyncWaitOperator.java
---
    @@ -0,0 +1,224 @@
    +/*
    + * 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.streaming.api.operators.async;
    +
    +import org.apache.flink.annotation.Internal;
    +import org.apache.flink.annotation.VisibleForTesting;
    +import org.apache.flink.api.common.state.ListState;
    +import org.apache.flink.api.common.state.ListStateDescriptor;
    +import org.apache.flink.api.common.typeutils.TypeSerializer;
    +import org.apache.flink.runtime.state.StateInitializationContext;
    +import org.apache.flink.runtime.state.StateSnapshotContext;
    +import org.apache.flink.streaming.api.datastream.AsyncDataStream;
    +import org.apache.flink.streaming.api.functions.async.AsyncFunction;
    +import org.apache.flink.streaming.api.graph.StreamConfig;
    +import org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator;
    +import org.apache.flink.streaming.api.operators.ChainingStrategy;
    +import org.apache.flink.streaming.api.operators.OneInputStreamOperator;
    +import org.apache.flink.streaming.api.operators.Output;
    +import org.apache.flink.streaming.api.operators.TimestampedCollector;
    +import org.apache.flink.streaming.api.watermark.Watermark;
    +import org.apache.flink.streaming.runtime.streamrecord.LatencyMarker;
    +import org.apache.flink.streaming.runtime.streamrecord.StreamElement;
    +import org.apache.flink.streaming.runtime.streamrecord.StreamElementSerializer;
    +import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
    +import org.apache.flink.streaming.runtime.tasks.StreamTask;
    +import org.apache.flink.util.Preconditions;
    +
    +import java.util.Collection;
    +
    +@Internal
    +public class AsyncWaitOperator<IN, OUT>
    +	extends AbstractUdfStreamOperator<OUT, AsyncFunction<IN, OUT>>
    +	implements OneInputStreamOperator<IN, OUT>
    +{
    +	private final int DEFAULT_BUFFER_SIZE = 1000;
    +
    +	private static final long serialVersionUID = 1L;
    +
    +	private final static String STATE_NAME = "_async_wait_operator_state_";
    +
    +	/**
    +	 * {@link TypeSerializer} for inputs while making snapshots.
    +	 */
    +	private transient StreamElementSerializer<IN> inStreamElementSerializer;
    +
    +	/**
    +	 * input stream elements from the state
    +	 */
    +	private transient ListState<StreamElement> recoveredStreamElements;
    +
    +	private transient TimestampedCollector<OUT> collector;
    +
    +	private transient AsyncCollectorBuffer<IN, OUT> buffer;
    +
    +	/**
    +	 * Checkpoint lock from {@link StreamTask#lock}
    +	 */
    +	private transient Object checkpointLock;
    +
    +	private int bufferSize = DEFAULT_BUFFER_SIZE;
    +	private AsyncDataStream.OutputMode mode;
    +
    +	/**
    +	 * For test only. Normally this flag is true, indicating that the Emitter Thread
    +	 * in the buffer will work.
    +	 */
    +	private boolean emitFlag = true;
    +
    +	/**
    +	 * Test serializer used in unit test
    +	 */
    +	private StreamElementSerializer<IN> inStreamElementSerializerForTest;
    +
    +
    +	public AsyncWaitOperator(AsyncFunction<IN, OUT> asyncFunction) {
    +		super(asyncFunction);
    +		chainingStrategy = ChainingStrategy.ALWAYS;
    +	}
    +
    +	public void setBufferSize(int size) {
    +		Preconditions.checkArgument(size > 0, "The number of concurrent async operation
should be greater than 0.");
    +		bufferSize = size;
    +	}
    +
    +	public void setOutputMode(AsyncDataStream.OutputMode mode) {
    +		this.mode = mode;
    +	}
    +
    +	@VisibleForTesting
    +	public void setEmitFlag(boolean emitFlag) {
    +		this.emitFlag = emitFlag;
    +	}
    +
    +	@VisibleForTesting
    +	public void setInStreamElementSerializerForTest(StreamElementSerializer<IN> serializer)
{
    +		this.inStreamElementSerializerForTest = serializer;
    +	}
    +
    +	@Override
    +	public void setup(StreamTask<?, ?> containingTask, StreamConfig config, Output<StreamRecord<OUT>>
output) {
    +		super.setup(containingTask, config, output);
    +
    +		if (this.inStreamElementSerializerForTest != null) {
    +			this.inStreamElementSerializer = this.inStreamElementSerializerForTest;
    +		}
    +		else {
    +			this.inStreamElementSerializer = new StreamElementSerializer(this.getOperatorConfig().getTypeSerializerIn1(getUserCodeClassloader()));
    +		}
    +
    +		this.collector = new TimestampedCollector<>(output);
    +
    +		this.checkpointLock = containingTask.getCheckpointLock();
    +
    +		this.buffer = new AsyncCollectorBuffer<>(bufferSize, mode, output, collector,
this.checkpointLock, this);
    +
    +	}
    +
    +	@Override
    +	public void open() throws Exception {
    +		super.open();
    +
    +		// process stream elements from state
    +		if (this.recoveredStreamElements != null) {
    +			for (StreamElement element : this.recoveredStreamElements.get()) {
    +				if (element.isRecord()) {
    +					processElement(element.<IN>asRecord());
    +				}
    +				else if (element.isWatermark()) {
    +					processWatermark(element.asWatermark());
    +				}
    +				else if (element.isLatencyMarker()) {
    +					processLatencyMarker(element.asLatencyMarker());
    +				}
    +				else {
    +					throw new Exception("Unknown record type: "+element.getClass());
    +				}
    +			}
    +			this.recoveredStreamElements = null;
    +		}
    +
    +
    +		if (emitFlag) {
    +			buffer.startEmitterThread();
    +		}
    +	}
    +
    +	@Override
    +	public void processElement(StreamRecord<IN> element) throws Exception {
    +		AsyncCollector<IN, OUT> collector = buffer.addStreamRecord(element);
    +
    +		userFunction.asyncInvoke(element.getValue(), collector);
    +	}
    +
    +	@Override
    +	public void processWatermark(Watermark mark) throws Exception {
    +		buffer.addWatermark(mark);
    +	}
    +
    +	@Override
    +	public void processLatencyMarker(LatencyMarker latencyMarker) throws Exception {
    +		buffer.addLatencyMarker(latencyMarker);
    +	}
    +
    +	@Override
    +	public void snapshotState(StateSnapshotContext context) throws Exception {
    +		super.snapshotState(context);
    +
    +		ListState<StreamElement> partitionableState =
    +				getOperatorStateBackend().getOperatorState(new ListStateDescriptor<>(STATE_NAME,
inStreamElementSerializer));
    +		partitionableState.clear();
    +
    +		Collection<StreamElement> elements = buffer.getStreamElementsInBuffer();
    +		for (StreamElement element : elements) {
    +			partitionableState.add(element);
    +		}
    +	}
    +
    +	@Override
    +	public void initializeState(StateInitializationContext context) throws Exception {
    +		recoveredStreamElements =
    +				context.getManagedOperatorStateStore().getOperatorState(new ListStateDescriptor<>(STATE_NAME,
inStreamElementSerializer));
    +
    +	}
    +
    +	@Override
    +	public void close() throws Exception {
    +		// for test only, we do not have to wait until buffer is empty.
    +		if (!emitFlag) {
    +			return;
    +		}
    +
    +		buffer.waitEmpty();
    +		buffer.stopEmitterThread();
    --- End diff --
    
    I think we should still stop the emitter thread even if an exception is thrown by `buffer.waitEmpty`
otherwise there might be a resource leak.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message