| /** |
| * 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.heron.examples.api; |
| |
| import java.util.Map; |
| import java.util.Random; |
| |
| import org.apache.heron.api.Config; |
| import org.apache.heron.api.HeronSubmitter; |
| import org.apache.heron.api.bolt.BaseRichBolt; |
| import org.apache.heron.api.bolt.OutputCollector; |
| import org.apache.heron.api.metric.GlobalMetrics; |
| import org.apache.heron.api.spout.BaseRichSpout; |
| import org.apache.heron.api.spout.SpoutOutputCollector; |
| import org.apache.heron.api.topology.OutputFieldsDeclarer; |
| import org.apache.heron.api.topology.TopologyBuilder; |
| import org.apache.heron.api.topology.TopologyContext; |
| import org.apache.heron.api.tuple.Fields; |
| import org.apache.heron.api.tuple.Tuple; |
| import org.apache.heron.api.tuple.Values; |
| |
| /** |
| * This is a basic example of a Heron topology with acking enable. |
| */ |
| public final class AckingTopology { |
| |
| private AckingTopology() { |
| } |
| |
| public static void main(String[] args) throws Exception { |
| if (args.length != 1) { |
| throw new RuntimeException("Specify topology name"); |
| } |
| TopologyBuilder builder = new TopologyBuilder(); |
| |
| int spouts = 2; |
| int bolts = 2; |
| builder.setSpout("word", new AckingTestWordSpout(), spouts); |
| builder.setBolt("exclaim1", new ExclamationBolt(), bolts) |
| .shuffleGrouping("word"); |
| |
| Config conf = new Config(); |
| conf.setDebug(true); |
| |
| // Specifies that all tuples will be automatically failed if not acked within 10 seconds |
| conf.setMessageTimeoutSecs(10); |
| |
| // Put an arbitrarily large number here if you don't want to slow the topology down |
| conf.setMaxSpoutPending(1000 * 1000 * 1000); |
| |
| // To enable at-least-once delivery semantics |
| conf.setTopologyReliabilityMode(Config.TopologyReliabilityMode.ATLEAST_ONCE); |
| |
| // Extra JVM options |
| conf.put(Config.TOPOLOGY_WORKER_CHILDOPTS, "-XX:+HeapDumpOnOutOfMemoryError"); |
| |
| // Component resource configuration |
| conf.setComponentRam("word", ExampleResources.getComponentRam()); |
| conf.setComponentRam("exclaim1", ExampleResources.getComponentRam()); |
| |
| // Container resource configuration |
| conf.setContainerDiskRequested( |
| ExampleResources.getContainerDisk(spouts + bolts, 2)); |
| conf.setContainerRamRequested( |
| ExampleResources.getContainerRam(spouts + bolts, 2)); |
| conf.setContainerCpuRequested( |
| ExampleResources.getContainerCpu(spouts + bolts, 2)); |
| |
| // Set the number of workers or stream managers |
| conf.setNumStmgrs(2); |
| HeronSubmitter.submitTopology(args[0], conf, builder.createTopology()); |
| } |
| |
| public static class AckingTestWordSpout extends BaseRichSpout { |
| |
| private static final long serialVersionUID = -630307949908406294L; |
| private SpoutOutputCollector collector; |
| private String[] words; |
| private Random rand; |
| |
| public AckingTestWordSpout() { |
| } |
| |
| @SuppressWarnings("rawtypes") |
| public void open( |
| Map conf, |
| TopologyContext context, |
| SpoutOutputCollector acollector) { |
| collector = acollector; |
| words = new String[]{"nathan", "mike", "jackson", "golda", "bertels"}; |
| rand = new Random(); |
| } |
| |
| public void close() { |
| } |
| |
| public void nextTuple() { |
| final String word = words[rand.nextInt(words.length)]; |
| |
| // To enable acking, we need to emit each tuple with a MessageId, which is an Object. |
| // Each new message emitted needs to be annotated with a unique ID, which allows |
| // the spout to keep track of which messages should be acked back to the producer or |
| // retried when the appropriate ack/fail happens. For the sake of simplicity here, |
| // however, we'll tag all tuples with the same message ID. |
| collector.emit(new Values(word), "MESSAGE_ID"); |
| } |
| |
| // Specifies what happens when an ack is received from downstream bolts |
| public void ack(Object msgId) { |
| } |
| |
| // Specifies what happens when a tuple is failed by a downstream bolt |
| public void fail(Object msgId) { |
| } |
| |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| declarer.declare(new Fields("word")); |
| } |
| } |
| |
| public static class ExclamationBolt extends BaseRichBolt { |
| private static final long serialVersionUID = -2267338658317778214L; |
| private OutputCollector collector; |
| private long nItems; |
| private long startTime; |
| |
| @Override |
| @SuppressWarnings("rawtypes") |
| public void prepare(Map conf, TopologyContext context, OutputCollector acollector) { |
| collector = acollector; |
| nItems = 0; |
| startTime = System.currentTimeMillis(); |
| } |
| |
| @Override |
| public void execute(Tuple tuple) { |
| // We need to ack a tuple when we deem that some operation has successfully completed. |
| // Tuples can also be failed by invoking collector.fail(tuple) |
| // If we do not explicitly ack or fail the tuple after MessageTimeout seconds, which |
| // can be set in the topology config, the spout will automatically fail the tuple |
| ++nItems; |
| if (nItems % 10000 == 0) { |
| long latency = System.currentTimeMillis() - startTime; |
| System.out.println("Bolt processed " + nItems + " tuples in " + latency + " ms"); |
| GlobalMetrics.incr("selected_items"); |
| // Here we explicitly forget to do the ack or fail |
| // It would trigger fail on this tuple on spout end after MessageTimeout Seconds |
| } else if (nItems % 2 == 0) { |
| collector.fail(tuple); |
| } else { |
| collector.ack(tuple); |
| } |
| } |
| |
| @Override |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| } |
| } |
| } |