org.apache.hadoop.metrics2.lib.MutableRates 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.metrics2.lib;
import java.lang.reflect.Method;
import java.util.Set;
import static org.apache.hadoop.thirdparty.com.google.common.base.Preconditions.*;
import org.apache.hadoop.thirdparty.com.google.common.collect.Sets;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.metrics2.MetricsRecordBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Helper class to manage a group of mutable rate metrics
*
* This class synchronizes all accesses to the metrics it
* contains, so it should not be used in situations where
* there is high contention on the metrics.
* {@link MutableRatesWithAggregation} is preferable in that
* situation.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public class MutableRates extends MutableMetric {
static final Logger LOG = LoggerFactory.getLogger(MutableRates.class);
private final MetricsRegistry registry;
private final Set> protocolCache = Sets.newHashSet();
MutableRates(MetricsRegistry registry) {
this.registry = checkNotNull(registry, "metrics registry");
}
/**
* Initialize the registry with all the methods in a protocol
* so they all show up in the first snapshot.
* Convenient for JMX implementations.
* @param protocol the protocol class
*/
public void init(Class protocol) {
if (protocolCache.contains(protocol)) return;
protocolCache.add(protocol);
for (Method method : protocol.getDeclaredMethods()) {
String name = method.getName();
LOG.debug(name);
try { registry.newRate(name, name, false, true); }
catch (Exception e) {
LOG.error("Error creating rate metrics for "+ method.getName(), e);
}
}
}
/**
* Add a rate sample for a rate metric
* @param name of the rate metric
* @param elapsed time
*/
public void add(String name, long elapsed) {
registry.add(name, elapsed);
}
@Override
public void snapshot(MetricsRecordBuilder rb, boolean all) {
registry.snapshot(rb, all);
}
}