org.ehcache.management.CacheStatisticsMXBean Maven / Gradle / Ivy
/*
* Copyright Terracotta, Inc.
*
* Licensed 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.ehcache.management;
/**
*
* @author Hung Huynh
*
*/
public interface CacheStatisticsMXBean {
/**
* The number of get requests that were satisfied by the cache.
*
* {@link org.ehcache.Cache#containsKey(Object)} is not a get request for
* statistics purposes.
*
* @return the number of hits
*/
long getCacheHits();
/**
* This is a measure of cache efficiency.
*
* It is calculated as:
* {@link #getCacheHits} divided by {@link #getCacheGets ()} * 100.
*
* @return the percentage of successful hits, as a decimal e.g 75.
*/
float getCacheHitPercentage();
/**
* A miss is a get request that is not satisfied.
*
* In a simple cache a miss occurs when the cache does not satisfy the request.
*
* {@link org.ehcache.Cache#containsKey(Object)} is not a get request for
* statistics purposes.
*
* @return the number of misses
*/
long getCacheMisses();
/**
* Returns the percentage of cache accesses that did not find a requested entry
* in the cache.
*
* This is calculated as {@link #getCacheMisses()} divided by
* {@link #getCacheGets()} * 100.
*
* @return the percentage of accesses that failed to find anything
*/
float getCacheMissPercentage();
/**
* The total number of requests to the cache. This will be equal to the sum of
* the hits and misses.
*
* A "get" is an operation that returns the current or previous value. It does
* not include checking for the existence of a key.
*
*
* @return the number of gets
*/
long getCacheGets();
/**
* The total number of puts to the cache.
*
* A put is counted even if it is immediately evicted.
*
* Replaces, where a put occurs which overrides an existing mapping is counted
* as a put.
*
* @return the number of puts
*/
long getCachePuts();
/**
* The total number of removals from the cache. This does not include evictions,
* where the cache itself initiates the removal to make space.
*
* @return the number of removals
*/
long getCacheRemovals();
/**
* The total number of evictions from the cache. An eviction is a removal
* initiated by the cache itself to free up space. An eviction is not treated as
* a removal and does not appear in the removal counts.
*
* @return the number of evictions
*/
long getCacheEvictions();
/**
* The mean time to execute gets.
*
* In a read-through cache the time taken to load an entry on miss is not
* included in get time.
*
* @return the time in µs
*/
float getAverageGetTime();
/**
* The mean time to execute puts.
*
* @return the time in µs
*/
float getAveragePutTime();
/**
* The mean time to execute removes.
*
* @return the time in µs
*/
float getAverageRemoveTime();
}