/**
* 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.falcon.rerun.handler;
import org.apache.falcon.FalconException;
import org.apache.falcon.aspect.GenericAlert;
import org.apache.falcon.entity.v0.Frequency;
import org.apache.falcon.rerun.event.RerunEvent;
import org.apache.falcon.rerun.policy.AbstractRerunPolicy;
import org.apache.falcon.rerun.policy.ExpBackoffPolicy;
import org.apache.falcon.rerun.queue.DelayedQueue;
import org.apache.falcon.security.CurrentUser;
import org.apache.log4j.Logger;
/**
* Base class for a rerun consumer.
*
* @param <T> a rerun event
* @param <M> a rerun handler
*/
public abstract class AbstractRerunConsumer<T extends RerunEvent, M extends AbstractRerunHandler<T, DelayedQueue<T>>>
implements Runnable {
protected static final Logger LOG = Logger
.getLogger(AbstractRerunConsumer.class);
protected M handler;
public AbstractRerunConsumer(M handler) {
this.handler = handler;
}
@Override
public void run() {
int attempt = 1;
AbstractRerunPolicy policy = new ExpBackoffPolicy();
Frequency frequency = new Frequency("minutes(1)");
while (true) {
try {
T message;
try {
message = handler.takeFromQueue();
attempt = 1;
} catch (FalconException e) {
LOG.error("Error while reading message from the queue: ", e);
GenericAlert.alertRerunConsumerFailed(
"Error while reading message from the queue: ", e);
Thread.sleep(policy.getDelay(frequency, attempt));
handler.reconnect();
attempt++;
continue;
}
CurrentUser.authenticate(message.getWorkflowUser());
String jobStatus = handler.getWfEngine().getWorkflowStatus(
message.getClusterName(), message.getWfId());
handleRerun(message.getClusterName(), jobStatus, message);
} catch (Throwable e) {
LOG.error("Error in rerun consumer:", e);
}
}
}
protected abstract void handleRerun(String clusterName, String jobStatus, T message);
}