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From: bjlovegithub <git@git.apache.org>
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Subject: [GitHub] flink pull request #2629: [FLINK-4391] Provide support for asynchronous oper...
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Message-Id: <20161104055215.34633E03D1@git1-us-west.apache.org>
Date: Fri,  4 Nov 2016 05:52:15 +0000 (UTC)
archived-at: Fri, 04 Nov 2016 05:52:20 -0000

Github user bjlovegithub commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2629#discussion_r86492216
  
    --- Diff: flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/async/AsyncIOExample.java ---
    @@ -0,0 +1,194 @@
    +/*
    + * 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.examples.async;
    +
    +import org.apache.flink.api.common.functions.FlatMapFunction;
    +import org.apache.flink.api.java.tuple.Tuple2;
    +import org.apache.flink.configuration.Configuration;
    +import org.apache.flink.runtime.state.filesystem.FsStateBackend;
    +import org.apache.flink.streaming.api.CheckpointingMode;
    +import org.apache.flink.streaming.api.TimeCharacteristic;
    +import org.apache.flink.streaming.api.checkpoint.Checkpointed;
    +import org.apache.flink.streaming.api.datastream.AsyncDataStream;
    +import org.apache.flink.streaming.api.datastream.DataStream;
    +import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    +import org.apache.flink.streaming.api.functions.async.AsyncFunction;
    +import org.apache.flink.streaming.api.functions.async.RichAsyncFunction;
    +import org.apache.flink.streaming.api.functions.source.SourceFunction;
    +import org.apache.flink.streaming.api.operators.async.AsyncCollector;
    +import org.apache.flink.util.Collector;
    +
    +import java.util.ArrayList;
    +import java.util.List;
    +import java.util.Random;
    +import java.util.concurrent.ExecutorService;
    +import java.util.concurrent.Executors;
    +import java.util.concurrent.TimeUnit;
    +
    +/**
    + * Example to illustrates how to use {@link org.apache.flink.streaming.api.functions.async.AsyncFunction}
    + */
    +public class AsyncIOExample {
    +
    +	/**
    +	 * A checkpointed source.
    +	 */
    +	private static class SimpleSource implements SourceFunction<Integer>, Checkpointed<Integer> {
    +		private static final long serialVersionUID = 1L;
    +
    +		private volatile boolean isRunning = true;
    +		private int counter = 0;
    +		private int start = 0;
    +
    +		@Override
    +		public void restoreState(Integer state) throws Exception {
    +			this.start = state;
    +		}
    +
    +		@Override
    +		public Integer snapshotState(long checkpointId, long checkpointTimestamp) throws Exception {
    +			return start;
    +		}
    +
    +		public SimpleSource(int maxNum) {
    +			this.counter = maxNum;
    +		}
    +
    +		@Override
    +		public void run(SourceContext<Integer> ctx) throws Exception {
    +			while (start < counter && isRunning) {
    +				synchronized (ctx.getCheckpointLock()) {
    +					ctx.collect(start);
    +					++start;
    +				}
    +				Thread.sleep(10);
    +			}
    +		}
    +
    +		@Override
    +		public void cancel() {
    +			isRunning = false;
    +		}
    +	}
    +
    +
    +	public static void main(String[] args) throws Exception {
    +
    +		// obtain execution environment and set setBufferTimeout to 1 to enable
    +		// continuous flushing of the output buffers (lowest latency)
    +		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment()
    +			.setBufferTimeout(1);
    +
    +		// configurations for the job
    +		String statePath = args[0];
    +		String cpMode = args[1];
    +		int maxCount = Integer.valueOf(args[2]);
    +		final int sleepFactor = Integer.valueOf(args[3]);
    +		final float failRatio = Float.valueOf(args[4]);
    +		String mode = args[5];
    +		int taskNum = Integer.valueOf(args[6]);
    +		String timeType = args[7];
    +
    +		// setup state and checkpoint mode
    +		env.setStateBackend(new FsStateBackend(statePath));
    +		if (cpMode.equals("exactly_once")) {
    +			env.enableCheckpointing(1000, CheckpointingMode.EXACTLY_ONCE);
    +		}
    +		else {
    +			env.enableCheckpointing(1000, CheckpointingMode.AT_LEAST_ONCE);
    +			env.disableOperatorChaining();
    +		}
    +
    +		// enable watermark or not
    +		if (timeType.equals("EventTime")) {
    +			env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
    +		}
    +		else if (timeType.equals("IngestionTime")) {
    +			env.setStreamTimeCharacteristic(TimeCharacteristic.IngestionTime);
    +		}
    +
    +		// create input stream of integer pairs
    +		DataStream<Integer> inputStream = env.addSource(new SimpleSource(maxCount));
    +
    +		// create async function, which will *wait* for a while to simulate the process of async i/o
    +		AsyncFunction<Integer, String> function = new RichAsyncFunction<Integer, String>() {
    +			transient ExecutorService executorService;
    +
    +			@Override
    +			public void open(Configuration parameters) throws Exception {
    +				super.open(parameters);
    +				executorService = Executors.newFixedThreadPool(30);
    +			}
    +
    +			@Override
    +			public void close() throws Exception {
    +				super.close();
    +				executorService.shutdown();
    +				executorService.awaitTermination(sleepFactor*20, TimeUnit.MILLISECONDS);
    +			}
    +
    +			@Override
    +			public void asyncInvoke(final Integer input, final AsyncCollector<Integer, String> collector) throws Exception {
    +				this.executorService.submit(new Runnable() {
    +					@Override
    +					public void run() {
    +						// wait for while to simulate async operation here
    +						int sleep = (int) (new Random().nextFloat() * sleepFactor);
    --- End diff --
    
    fixed


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