/*
* 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.flume.sink;
import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.flume.CounterGroup;
import org.apache.flume.EventDeliveryException;
import org.apache.flume.PollableSink;
import org.apache.flume.SinkRunner;
import org.apache.flume.lifecycle.LifecycleState;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class PollableSinkRunner extends SinkRunner {
private static final Logger logger = LoggerFactory
.getLogger(PollableSinkRunner.class);
private static final long backoffSleepIncrement = 1000;
private static final long maxBackoffSleep = 5000;
private CounterGroup counterGroup;
private PollingRunner runner;
private Thread runnerThread;
private LifecycleState lifecycleState;
public PollableSinkRunner() {
counterGroup = new CounterGroup();
lifecycleState = LifecycleState.IDLE;
}
@Override
public void start() {
PollableSink sink = (PollableSink) getSink();
sink.start();
runner = new PollingRunner();
runner.sink = sink;
runner.counterGroup = counterGroup;
runner.shouldStop = new AtomicBoolean();
runnerThread = new Thread(runner);
runnerThread.start();
lifecycleState = LifecycleState.START;
}
@Override
public void stop() {
getSink().stop();
if (runnerThread != null) {
runner.shouldStop.set(true);
runnerThread.interrupt();
while (runnerThread.isAlive()) {
try {
logger.debug("Waiting for runner thread to exit");
runnerThread.join(500);
} catch (InterruptedException e) {
logger
.debug(
"Interrupted while waiting for runner thread to exit. Exception follows.",
e);
}
}
}
lifecycleState = LifecycleState.STOP;
}
@Override
public String toString() {
return "PollableSinkRunner: { sink:" + getSink() + " counterGroup:"
+ counterGroup + " }";
}
@Override
public LifecycleState getLifecycleState() {
return lifecycleState;
}
public static class PollingRunner implements Runnable {
private PollableSink sink;
private AtomicBoolean shouldStop;
private CounterGroup counterGroup;
@Override
public void run() {
logger.debug("Polling sink runner starting");
while (!shouldStop.get()) {
try {
if (sink.process().equals(PollableSink.Status.BACKOFF)) {
counterGroup.incrementAndGet("runner.backoffs");
Thread.sleep(Math.min(
counterGroup.incrementAndGet("runner.backoffs.consecutive")
* backoffSleepIncrement, maxBackoffSleep));
} else {
counterGroup.set("runner.backoffs.consecutive", 0L);
}
} catch (InterruptedException e) {
logger.debug("Interrupted while processing an event. Exiting.");
counterGroup.incrementAndGet("runner.interruptions");
} catch (EventDeliveryException e) {
logger.error("Unable to deliver event. Exception follows.", e);
counterGroup.incrementAndGet("runner.errors");
}
}
logger.debug("Polling runner exiting. Metrics:{}", counterGroup);
}
}
}