org.apache.hadoop.fs.statistics.impl.StatisticDurationTracker Maven / Gradle / Ivy
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* 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.hadoop.fs.statistics.impl;
import org.apache.hadoop.fs.statistics.DurationTracker;
import org.apache.hadoop.fs.statistics.StoreStatisticNames;
import org.apache.hadoop.util.OperationDuration;
/**
* Track the duration of an object.
*
* When closed the
* min/max/mean statistics are updated.
*
* In the constructor, the counter with name of 'key' is
* incremented -default is by 1, but can be set to other
* values, including 0.
*/
public class StatisticDurationTracker extends OperationDuration
implements DurationTracker {
/**
* Statistics to update.
*/
private final IOStatisticsStore iostats;
/**
* Key to use as prefix of values.
*/
private final String key;
/**
* Flag to indicate the operation failed.
*/
private boolean failed;
/**
* Constructor -increments the counter by 1.
* @param iostats statistics to update
* @param key prefix of values.
*/
public StatisticDurationTracker(
final IOStatisticsStore iostats,
final String key) {
this(iostats, key, 1);
}
/**
* Constructor.
* If the supplied count is greater than zero, the counter
* of the key name is updated.
* @param iostats statistics to update
* @param key Key to use as prefix of values.
* @param count #of times to increment the matching counter.
*/
public StatisticDurationTracker(
final IOStatisticsStore iostats,
final String key,
final long count) {
this.iostats = iostats;
this.key = key;
if (count > 0) {
iostats.incrementCounter(key, count);
}
}
@Override
public void failed() {
failed = true;
}
/**
* Set the finished time and then update the statistics.
* If the operation failed then the key + .failures counter will be
* incremented by one.
* The operation min/mean/max values will be updated with the duration;
* on a failure these will all be the .failures metrics.
*/
@Override
public void close() {
finished();
String name = key;
if (failed) {
// failure:
name = key + StoreStatisticNames.SUFFIX_FAILURES;
iostats.incrementCounter(name);
}
iostats.addTimedOperation(name, asDuration());
}
}