/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. 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 com.cloudera.flume.handlers.debug;
import java.io.IOException;
import com.cloudera.flume.agent.FlumeNode;
import com.cloudera.flume.conf.Context;
import com.cloudera.flume.conf.SinkFactory.SinkDecoBuilder;
import com.cloudera.flume.core.Event;
import com.cloudera.flume.core.EventSink;
import com.cloudera.flume.core.EventSinkDecorator;
import com.google.common.base.Preconditions;
/**
* This decorator adds a the capability to Throttle the data going out of the
* sink. Each ChokeDecorator is associated with a chokeId, and all the
* choke-decorators with the same chokeId are throttled together with some max
* data transfer limit. The mapping from the chokeId to limit is set by the
* Master and passed to FlumeNodes using an RPC call called getChokeMap().
*/
public class ChokeDecorator<S extends EventSink> extends EventSinkDecorator<S> {
// this is the throttling limit set in KB/sec.
final String chokeId;
private ChokeManager chokeMan;
public ChokeDecorator(S s, String tId) {
super(s);
chokeId = tId;
}
/**
* This append can block for a little while if the number of bytes shipped
* across this Choke has reached its limit. But it does not block forever.
*/
@Override
public void append(Event e) throws IOException, InterruptedException {
chokeMan.spendTokens(chokeId, e.getBody().length);
super.append(e);
}
/**
* {@inheritDoc}
*/
@Override
public void open() throws IOException, InterruptedException {
this.chokeMan = FlumeNode.getInstance().getChokeManager();
super.open();
}
/**
* Returns the ChokeId corresponding to this choke.
*/
public String getChokeId() {
return chokeId;
}
public static SinkDecoBuilder builder() {
return new SinkDecoBuilder() {
// In the current version we don't check if the id (argv[0]) is valid
// chokeId.
// If it is not, then this this choke decorator will have no throttling
// limit.
@Override
public EventSinkDecorator<EventSink> build(Context context,
String... argv) {
Preconditions.checkArgument(argv.length == 1,
"usage: choke(\"chokeId\")");
String chokeID = argv[0];
return new ChokeDecorator<EventSink>(null, chokeID);
}
};
}
}