/**
* 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 backtype.storm.task;
import backtype.storm.Config;
import backtype.storm.generated.ShellComponent;
import backtype.storm.metric.api.IMetric;
import backtype.storm.metric.api.rpc.IShellMetric;
import backtype.storm.topology.ReportedFailedException;
import backtype.storm.tuple.MessageId;
import backtype.storm.tuple.Tuple;
import backtype.storm.utils.ShellProcess;
import backtype.storm.multilang.BoltMsg;
import backtype.storm.multilang.ShellMsg;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.LinkedBlockingQueue;
import static java.util.concurrent.TimeUnit.SECONDS;
import java.util.Map;
import java.util.Random;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A bolt that shells out to another process to process tuples. ShellBolt
* communicates with that process over stdio using a special protocol. An ~100
* line library is required to implement that protocol, and adapter libraries
* currently exist for Ruby and Python.
*
* <p>To run a ShellBolt on a cluster, the scripts that are shelled out to must be
* in the resources directory within the jar submitted to the master.
* During development/testing on a local machine, that resources directory just
* needs to be on the classpath.</p>
*
* <p>When creating topologies using the Java API, subclass this bolt and implement
* the IRichBolt interface to create components for the topology that use other languages. For example:
* </p>
*
* <pre>
* public class MyBolt extends ShellBolt implements IRichBolt {
* public MyBolt() {
* super("python", "mybolt.py");
* }
*
* public void declareOutputFields(OutputFieldsDeclarer declarer) {
* declarer.declare(new Fields("field1", "field2"));
* }
* }
* </pre>
*/
public class ShellBolt implements IBolt {
public static Logger LOG = LoggerFactory.getLogger(ShellBolt.class);
Process _subprocess;
OutputCollector _collector;
Map<String, Tuple> _inputs = new ConcurrentHashMap<String, Tuple>();
private String[] _command;
private ShellProcess _process;
private volatile boolean _running = true;
private volatile Throwable _exception;
private LinkedBlockingQueue _pendingWrites = new LinkedBlockingQueue();
private Random _rand;
private Thread _readerThread;
private Thread _writerThread;
private TopologyContext _context;
public ShellBolt(ShellComponent component) {
this(component.get_execution_command(), component.get_script());
}
public ShellBolt(String... command) {
_command = command;
}
public void prepare(Map stormConf, TopologyContext context,
final OutputCollector collector) {
Object maxPending = stormConf.get(Config.TOPOLOGY_SHELLBOLT_MAX_PENDING);
if (maxPending != null) {
this._pendingWrites = new LinkedBlockingQueue(((Number)maxPending).intValue());
}
_rand = new Random();
_collector = collector;
_context = context;
_process = new ShellProcess(_command);
//subprocesses must send their pid first thing
Number subpid = _process.launch(stormConf, context);
LOG.info("Launched subprocess with pid " + subpid);
// reader
_readerThread = new Thread(new Runnable() {
public void run() {
while (_running) {
try {
ShellMsg shellMsg = _process.readShellMsg();
String command = shellMsg.getCommand();
if (command == null) {
throw new IllegalArgumentException("Command not found in bolt message: " + shellMsg);
}
if(command.equals("ack")) {
handleAck(shellMsg.getId());
} else if (command.equals("fail")) {
handleFail(shellMsg.getId());
} else if (command.equals("error")) {
handleError(shellMsg.getMsg());
} else if (command.equals("log")) {
handleLog(shellMsg);
} else if (command.equals("emit")) {
handleEmit(shellMsg);
} else if (command.equals("metrics")) {
handleMetrics(shellMsg);
}
} catch (InterruptedException e) {
} catch (Throwable t) {
die(t);
}
}
}
});
_readerThread.start();
_writerThread = new Thread(new Runnable() {
public void run() {
while (_running) {
try {
Object write = _pendingWrites.poll(1, SECONDS);
if (write instanceof BoltMsg) {
_process.writeBoltMsg((BoltMsg)write);
} else if (write instanceof List<?>) {
_process.writeTaskIds((List<Integer>)write);
} else if (write != null) {
throw new RuntimeException("Unknown class type to write: " + write.getClass().getName());
}
} catch (InterruptedException e) {
} catch (Throwable t) {
die(t);
}
}
}
});
_writerThread.start();
}
public void execute(Tuple input) {
if (_exception != null) {
throw new RuntimeException(_exception);
}
//just need an id
String genId = Long.toString(_rand.nextLong());
_inputs.put(genId, input);
try {
BoltMsg boltMsg = new BoltMsg();
boltMsg.setId(genId);
boltMsg.setComp(input.getSourceComponent());
boltMsg.setStream(input.getSourceStreamId());
boltMsg.setTask(input.getSourceTask());
boltMsg.setTuple(input.getValues());
_pendingWrites.put(boltMsg);
} catch(InterruptedException e) {
String processInfo = _process.getProcessInfoString() + _process.getProcessTerminationInfoString();
throw new RuntimeException("Error during multilang processing " + processInfo, e);
}
}
public void cleanup() {
_running = false;
_writerThread.interrupt();
_readerThread.interrupt();
_process.destroy();
_inputs.clear();
}
private void handleAck(Object id) {
Tuple acked = _inputs.remove(id);
if(acked==null) {
throw new RuntimeException("Acked a non-existent or already acked/failed id: " + id);
}
_collector.ack(acked);
}
private void handleFail(Object id) {
Tuple failed = _inputs.remove(id);
if(failed==null) {
throw new RuntimeException("Failed a non-existent or already acked/failed id: " + id);
}
_collector.fail(failed);
}
private void handleError(String msg) {
_collector.reportError(new Exception("Shell Process Exception: " + msg));
}
private void handleEmit(ShellMsg shellMsg) throws InterruptedException {
List<Tuple> anchors = new ArrayList<Tuple>();
List<String> recvAnchors = shellMsg.getAnchors();
if (recvAnchors != null) {
for (String anchor : recvAnchors) {
Tuple t = _inputs.get(anchor);
if (t == null) {
throw new RuntimeException("Anchored onto " + anchor + " after ack/fail");
}
anchors.add(t);
}
}
if(shellMsg.getTask() == 0) {
List<Integer> outtasks = _collector.emit(shellMsg.getStream(), anchors, shellMsg.getTuple());
if (shellMsg.areTaskIdsNeeded()) {
_pendingWrites.put(outtasks);
}
} else {
_collector.emitDirect((int) shellMsg.getTask(),
shellMsg.getStream(), anchors, shellMsg.getTuple());
}
}
private void handleLog(ShellMsg shellMsg) {
String msg = shellMsg.getMsg();
msg = "ShellLog " + _process.getProcessInfoString() + " " + msg;
ShellMsg.ShellLogLevel logLevel = shellMsg.getLogLevel();
switch (logLevel) {
case TRACE:
LOG.trace(msg);
break;
case DEBUG:
LOG.debug(msg);
break;
case INFO:
LOG.info(msg);
break;
case WARN:
LOG.warn(msg);
break;
case ERROR:
LOG.error(msg);
_collector.reportError(new ReportedFailedException(msg));
break;
default:
LOG.info(msg);
break;
}
}
private void handleMetrics(ShellMsg shellMsg) {
//get metric name
String name = shellMsg.getMetricName();
if (name.isEmpty()) {
throw new RuntimeException("Receive Metrics name is empty");
}
//get metric by name
IMetric iMetric = _context.getRegisteredMetricByName(name);
if (iMetric == null) {
throw new RuntimeException("Could not find metric by name["+name+"] ");
}
if ( !(iMetric instanceof IShellMetric)) {
throw new RuntimeException("Metric["+name+"] is not IShellMetric, can not call by RPC");
}
IShellMetric iShellMetric = (IShellMetric)iMetric;
//call updateMetricFromRPC with params
Object paramsObj = shellMsg.getMetricParams();
try {
iShellMetric.updateMetricFromRPC(paramsObj);
} catch (RuntimeException re) {
throw re;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private void die(Throwable exception) {
String processInfo = _process.getProcessInfoString() + _process.getProcessTerminationInfoString();
_exception = new RuntimeException(processInfo, exception);
LOG.error("Halting process: ShellBolt died.", exception);
_collector.reportError(exception);
if (_running || (exception instanceof Error)) { //don't exit if not running, unless it is an Error
System.exit(11);
}
}
}