com.amazonaws.services.kinesis.multilang.MultiLangDaemon Maven / Gradle / Ivy
/*
* Copyright 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Amazon Software License (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/asl/
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.services.kinesis.multilang;
import java.io.IOException;
import java.io.PrintStream;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.amazonaws.services.kinesis.clientlibrary.interfaces.v2.IRecordProcessorFactory;
import com.amazonaws.services.kinesis.clientlibrary.lib.worker.KinesisClientLibConfiguration;
import com.amazonaws.services.kinesis.clientlibrary.lib.worker.Worker;
/**
* Main app that launches the worker that runs the multi-language record processor.
*
* Requires a properties file containing configuration for this daemon and the KCL. A properties file should at minimum
* define these properties:
*
*
* # The script that abides by the multi-language protocol. This script will
* # be executed by the MultiLangDaemon, which will communicate with this script
* # over STDIN and STDOUT according to the multi-language protocol.
* executableName = sampleapp.py
*
* # The name of an Amazon Kinesis stream to process.
* streamName = words
*
* # Used by the KCL as the name of this application. Will be used as the name
* # of a Amazon DynamoDB table which will store the lease and checkpoint
* # information for workers with this application name.
* applicationName = PythonKCLSample
*
* # Users can change the credentials provider the KCL will use to retrieve credentials.
* # The DefaultAWSCredentialsProviderChain checks several other providers, which is
* # described here:
* # http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/auth/DefaultAWSCredentialsProviderChain.html
* AWSCredentialsProvider = DefaultAWSCredentialsProviderChain
*
*/
public class MultiLangDaemon implements Callable {
private static final Log LOG = LogFactory.getLog(MultiLangDaemon.class);
private Worker worker;
/**
* Constructor.
*
* @param configuration The KCL config to use.
* @param recordProcessorFactory A record processor factory to create record processors that abide by the multi-lang
* protocol.
* @param workerThreadPool The executor service to run the daemon in.
*/
public MultiLangDaemon(KinesisClientLibConfiguration configuration,
MultiLangRecordProcessorFactory recordProcessorFactory,
ExecutorService workerThreadPool) {
this(buildWorker(recordProcessorFactory, configuration, workerThreadPool));
}
private static Worker buildWorker(IRecordProcessorFactory recordProcessorFactory,
KinesisClientLibConfiguration configuration, ExecutorService workerThreadPool) {
return new Worker.Builder().recordProcessorFactory(recordProcessorFactory).config(configuration)
.execService(workerThreadPool).build();
}
/**
*
* @param worker A worker to use instead of the default worker.
*/
public MultiLangDaemon(Worker worker) {
this.worker = worker;
}
/**
* Utility for describing how to run this app.
*
* @param stream Where to output the usage info.
* @param messageToPrepend An optional error message to describe why the usage is being printed.
*/
public static void printUsage(PrintStream stream, String messageToPrepend) {
StringBuilder builder = new StringBuilder();
if (messageToPrepend != null) {
builder.append(messageToPrepend);
}
builder.append(String.format("java %s ", MultiLangDaemon.class.getCanonicalName()));
stream.println(builder.toString());
}
@Override
public Integer call() throws Exception {
int exitCode = 0;
try {
worker.run();
} catch (Throwable t) {
LOG.error("Caught throwable while processing data.", t);
exitCode = 1;
}
return exitCode;
}
/**
* @param args Accepts a single argument, that argument is a properties file which provides KCL configuration as
* well as the name of an executable.
*/
public static void main(String[] args) {
if (args.length == 0) {
printUsage(System.err, "You must provide a properties file");
System.exit(1);
}
MultiLangDaemonConfig config = null;
try {
config = new MultiLangDaemonConfig(args[0]);
} catch (IOException e) {
printUsage(System.err, "You must provide a properties file");
System.exit(1);
} catch (IllegalArgumentException e) {
printUsage(System.err, e.getMessage());
System.exit(1);
}
ExecutorService executorService = config.getExecutorService();
// Daemon
final MultiLangDaemon daemon = new MultiLangDaemon(
config.getKinesisClientLibConfiguration(),
config.getRecordProcessorFactory(),
executorService);
final long shutdownGraceMillis = config.getKinesisClientLibConfiguration().getShutdownGraceMillis();
Runtime.getRuntime().addShutdownHook(new Thread() {
@Override
public void run() {
LOG.info("Process terminanted, will initiate shutdown.");
try {
Future fut = daemon.worker.requestShutdown();
fut.get(shutdownGraceMillis, TimeUnit.MILLISECONDS);
LOG.info("Process shutdown is complete.");
} catch (InterruptedException | ExecutionException | TimeoutException e) {
LOG.error("Encountered an error during shutdown.", e);
}
}
});
Future future = executorService.submit(daemon);
try {
System.exit(future.get());
} catch (InterruptedException | ExecutionException e) {
LOG.error("Encountered an error while running daemon", e);
}
System.exit(1);
}
}