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Management support using JMX.

There is a newer version: 3.5.0-beta03

/*
 * Copyright (c) 2002-2016 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see .
 */
package org.neo4j.management;

import org.neo4j.jmx.Description;
import org.neo4j.jmx.ManagementInterface;

@ManagementInterface( name = PageCache.NAME )
@Description( "Information about the Neo4j page cache. " +
              "All numbers are counts and sums since the Neo4j instance was started" )
public interface PageCache
{
    String NAME = "Page cache";

    @Description( "Number of page faults. How often requested data was not found in memory and had to be loaded." )
    long getFaults();

    @Description( "Number of page evictions. How many pages have been removed from memory to make room for other pages." )
    long getEvictions();

    @Description( "Number of page pins. How many pages have been accessed (monitoring must be enabled separately)." )
    long getPins();

    @Description( "Number of page flushes. How many dirty pages have been written to durable storage." )
    long getFlushes();

    @Description( "Number of bytes read from durable storage." )
    long getBytesRead();

    @Description( "Number of bytes written to durable storage." )
    long getBytesWritten();

    @Description( "Number of files that have been mapped into the page cache." )
    long getFileMappings();

    @Description( "Number of files that have been unmapped from the page cache." )
    long getFileUnmappings();

    @Description( "Number of exceptions caught during page eviction. " +
                  "This number should be zero, or at least not growing, in a healthy database. " +
                  "Otherwise it could indicate drive failure, storage space, or permission problems." )
    public long getEvictionExceptions();
}