/**
* 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 java.util.concurrent.atomic.AtomicLong;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.cloudera.flume.reporter.ReportEvent;
import com.cloudera.flume.reporter.Reportable;
import com.google.common.base.Preconditions;
/**
* A sink is "stubborn" if it attempts to reopen a connections if an IO
* exception is thrown during an append.
*
* This only catches one failure, consecutive failures will still through
* exception
*/
public class StubbornAppendSink<S extends EventSink> extends
EventSinkDecorator<S> implements Reportable {
public static final Logger LOG = LoggerFactory
.getLogger(StubbornAppendSink.class);
// attribute names
final public static String A_SUCCESSES = "appendSuccess";
final public static String A_FAILS = "appendFails";
final public static String A_RECOVERS = "appendRecovers";
AtomicLong appendSuccesses = new AtomicLong();
AtomicLong appendFails = new AtomicLong();
AtomicLong appendRecovers = new AtomicLong();
public StubbornAppendSink(S s) {
super(s);
}
@Override
public void open() throws IOException, InterruptedException {
Preconditions.checkNotNull(sink);
LOG.debug("Opening Stubborn Append Sink {}", this);
isOpen.set(true); // slightly different than default semantics -- open
// always keeps it in open state.
sink.open();
LOG.debug("Opened Stubborn Append Sink {}", this);
}
@Override
public void append(Event e) throws IOException, InterruptedException {
try {
super.append(e);
appendSuccesses.incrementAndGet();
return; // success case
} catch (Exception ex) {
LOG.info(ex.getMessage());
appendFails.incrementAndGet();
super.close(); // close
if (Thread.currentThread().isInterrupted()) {
throw new IOException(
"throwing exception because stubborn append was interrupted");
}
open(); // attempt to reopen
super.append(e); // resend
appendSuccesses.incrementAndGet();
// another exception may have been thrown at close/open/append
appendRecovers.incrementAndGet();
}
}
public static SinkDecoBuilder builder() {
return new SinkDecoBuilder() {
@Override
public EventSinkDecorator<EventSink> build(Context context,
String... argv) {
Preconditions.checkArgument(argv.length == 0, "usage: stubborn");
return new StubbornAppendSink<EventSink>(null);
}
};
}
@Override
public String getName() {
return "StubbornAppend";
}
@Override
public ReportEvent getMetrics() {
ReportEvent e = super.getMetrics();
e.setLongMetric(A_SUCCESSES, appendSuccesses.get());
e.setLongMetric(A_FAILS, appendFails.get());
e.setLongMetric(A_RECOVERS, appendRecovers.get());
return e;
}
@Deprecated
@Override
public ReportEvent getReport() {
ReportEvent e = super.getReport();
e.setLongMetric(A_SUCCESSES, appendSuccesses.get());
e.setLongMetric(A_FAILS, appendFails.get());
e.setLongMetric(A_RECOVERS, appendRecovers.get());
return e;
}
}