/**
* 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.util;
import com.cloudera.flume.reporter.ReportEvent;
/**
* This provides a simple reusable exponential backoff state object. Note that
* this only does calculations and tracks the backoff state but doesn't actually
* do backoffs (e.g. do blocking sleeps)! Later this could be pluggable with
* other backoff policies (maybe adaptive?)
*
* This policy has a max backoff per attempt and also a cumulative maximum
* failure time. After the cumulative time has expired isfailed will return true
*/
public class CumulativeCappedExponentialBackoff extends
CappedExponentialBackoff {
final long cumulativeCap;
long failTime;
final static public String A_CUMULATIVECAP = "backoffMaxCumulativeMs";
public CumulativeCappedExponentialBackoff(long initialSleep, long sleepCap,
long cumulativeCap) {
super(initialSleep, sleepCap);
this.cumulativeCap = cumulativeCap;
}
public void backoff() {
if (backoffCount == 0) {
failTime = Clock.unixTime() + cumulativeCap;
}
super.backoff();
}
public void reset() {
super.reset();
failTime = Long.MAX_VALUE;
}
/**
* Has so much time passed that we assume the failure is irrecoverable?
*/
public boolean isFailed() {
return failTime <= Clock.unixTime();
}
@Override
public String getName() {
return "CumulativeCappedExpBackoff";
}
@Override
public ReportEvent getMetrics() {
ReportEvent rpt = super.getMetrics();
rpt.setLongMetric(A_CUMULATIVECAP, cumulativeCap);
return rpt;
}
}