/**
* 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.cassandra.metrics;
import java.util.concurrent.TimeUnit;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.core.Gauge;
import com.yammer.metrics.core.Meter;
import com.yammer.metrics.util.RatioGauge;
import org.apache.cassandra.service.FileCacheService;
public class FileCacheMetrics
{
private static final MetricNameFactory factory = new DefaultNameFactory("FileCache");
/** Total number of hits */
public final Meter hits;
/** Total number of requests */
public final Meter requests;
/** hit rate */
public final Gauge<Double> hitRate;
/** Total size of file cache, in bytes */
public final Gauge<Long> size;
public FileCacheMetrics()
{
hits = Metrics.newMeter(factory.createMetricName("Hits"), "hits", TimeUnit.SECONDS);
requests = Metrics.newMeter(factory.createMetricName("Requests"), "requests", TimeUnit.SECONDS);
hitRate = Metrics.newGauge(factory.createMetricName("HitRate"), new RatioGauge()
{
protected double getNumerator()
{
return hits.count();
}
protected double getDenominator()
{
return requests.count();
}
});
size = Metrics.newGauge(factory.createMetricName("Size"), new Gauge<Long>()
{
public Long value()
{
return FileCacheService.instance.sizeInBytes();
}
});
}
}