org.apache.hadoop.metrics.util.MetricsTimeVaryingInt Maven / Gradle / Ivy
/**
* 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.metrics.util;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.metrics.MetricsRecord;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* The MetricsTimeVaryingInt class is for a metric that naturally
* varies over time (e.g. number of files created). The metrics is accumulated
* over an interval (set in the metrics config file); the metrics is
* published at the end of each interval and then
* reset to zero. Hence the counter has the value in the current interval.
*
* Note if one wants a time associated with the metric then use
* @see org.apache.hadoop.metrics.util.MetricsTimeVaryingRate
*
*/
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
public class MetricsTimeVaryingInt extends MetricsBase {
private static final Log LOG =
LogFactory.getLog("org.apache.hadoop.metrics.util");
private int currentValue;
private int previousIntervalValue;
/**
* Constructor - create a new metric
* @param nam the name of the metrics to be used to publish the metric
* @param registry - where the metrics object will be registered
* @param description - the description
*/
public MetricsTimeVaryingInt(final String nam,
final MetricsRegistry registry,
final String description) {
super(nam, description);
currentValue = 0;
previousIntervalValue = 0;
registry.add(nam, this);
}
/**
* Constructor - create a new metric
* @param nam the name of the metrics to be used to publish the metric
* @param registry - where the metrics object will be registered
* A description of {@link #NO_DESCRIPTION} is used
*/
public MetricsTimeVaryingInt(final String nam, final MetricsRegistry registry) {
this(nam, registry, NO_DESCRIPTION);
}
/**
* Inc metrics for incr vlaue
* @param incr - number of operations
*/
public synchronized void inc(final int incr) {
currentValue += incr;
}
/**
* Inc metrics by one
*/
public synchronized void inc() {
currentValue++;
}
private synchronized void intervalHeartBeat() {
previousIntervalValue = currentValue;
currentValue = 0;
}
/**
* Push the delta metrics to the mr.
* The delta is since the last push/interval.
*
* Note this does NOT push to JMX
* (JMX gets the info via {@link #previousIntervalValue}
*
* @param mr
*/
public synchronized void pushMetric(final MetricsRecord mr) {
intervalHeartBeat();
try {
mr.incrMetric(getName(), getPreviousIntervalValue());
} catch (Exception e) {
LOG.info("pushMetric failed for " + getName() + "\n" , e);
}
}
/**
* The Value at the Previous interval
* @return prev interval value
*/
public synchronized int getPreviousIntervalValue() {
return previousIntervalValue;
}
/**
* The Value at the current interval
* @return prev interval value
*/
public synchronized int getCurrentIntervalValue() {
return currentValue;
}
}