/**
* 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.hbase.metrics;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
/**
* A metric which measure the rate at which some operation is invoked.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface Meter extends Metric {
/**
* Records one occurrence.
*/
void mark();
/**
* Records {@code events} occurrences.
*
* @param events Number of occurrences to record.
*/
void mark(long events);
/**
* Returns the number of events.
* @return the number of events.
*/
long getCount();
/**
* Returns the mean rate at which events have occurred since the meter was created.
* @return the mean rate at which events have occurred since the meter was created
*/
double getMeanRate();
/**
* Returns the one-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created.
* <p/>
* This rate has the same exponential decay factor as the one-minute load average in the {@code
* top} Unix command.
*
* @return the one-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created
*/
double getOneMinuteRate();
/**
* Returns the five-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created.
* <p/>
* This rate has the same exponential decay factor as the five-minute load average in the {@code
* top} Unix command.
*
* @return the five-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created
*/
double getFiveMinuteRate();
/**
* Returns the fifteen-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created.
* <p/>
* This rate has the same exponential decay factor as the fifteen-minute load average in the
* {@code top} Unix command.
*
* @return the fifteen-minute exponentially-weighted moving average rate at which events have
* occurred since the meter was created
*/
double getFifteenMinuteRate();
}