001package org.apache.commons.jcs3.auxiliary.lateral; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import java.util.concurrent.ConcurrentHashMap; 023 024import org.apache.commons.jcs3.auxiliary.AbstractAuxiliaryCacheMonitor; 025import org.apache.commons.jcs3.auxiliary.lateral.socket.tcp.LateralTCPCacheFactory; 026import org.apache.commons.jcs3.auxiliary.lateral.socket.tcp.behavior.ITCPLateralCacheAttributes; 027import org.apache.commons.jcs3.engine.CacheStatus; 028import org.apache.commons.jcs3.engine.ZombieCacheServiceNonLocal; 029import org.apache.commons.jcs3.engine.behavior.ICacheServiceNonLocal; 030 031/** 032 * Used to monitor and repair any failed connection for the lateral cache service. By default the 033 * monitor operates in a failure driven mode. That is, it goes into a wait state until there is an 034 * error. Upon the notification of a connection error, the monitor changes to operate in a time 035 * driven mode. That is, it attempts to recover the connections on a periodic basis. When all failed 036 * connections are restored, it changes back to the failure driven mode. 037 */ 038public class LateralCacheMonitor extends AbstractAuxiliaryCacheMonitor 039{ 040 /** 041 * Map of caches to monitor 042 */ 043 private final ConcurrentHashMap<String, LateralCacheNoWait<Object, Object>> caches; 044 045 /** 046 * Reference to the factory 047 */ 048 private final LateralTCPCacheFactory factory; 049 050 /** 051 * Allows close classes, ie testers to set the idle period to something testable. 052 * <p> 053 * @param idlePeriod 054 * 055 * @deprecated Use setIdlePeriod() 056 */ 057 @Deprecated 058 protected static void forceShortIdlePeriod( final long idlePeriod ) 059 { 060 LateralCacheMonitor.setIdlePeriod(idlePeriod); 061 } 062 063 /** 064 * Constructor for the LateralCacheMonitor object 065 * <p> 066 * It's the clients responsibility to decide how many of these there will be. 067 * 068 * @param factory a reference to the factory that manages the service instances 069 */ 070 public LateralCacheMonitor(final LateralTCPCacheFactory factory) 071 { 072 super("JCS-LateralCacheMonitor"); 073 this.factory = factory; 074 this.caches = new ConcurrentHashMap<>(); 075 setIdlePeriod(20000L); 076 } 077 078 /** 079 * Add a cache to be monitored 080 * 081 * @param cache the cache 082 */ 083 @SuppressWarnings("unchecked") // common map for all caches 084 public void addCache(final LateralCacheNoWait<?, ?> cache) 085 { 086 this.caches.put(cache.getCacheName(), (LateralCacheNoWait<Object, Object>)cache); 087 088 // if not yet started, go ahead 089 if (this.getState() == Thread.State.NEW) 090 { 091 this.start(); 092 } 093 } 094 095 /** 096 * Clean up all resources before shutdown 097 */ 098 @Override 099 public void dispose() 100 { 101 this.caches.clear(); 102 } 103 104 /** 105 * Main processing method for the LateralCacheMonitor object 106 */ 107 @Override 108 public void doWork() 109 { 110 // Monitor each cache instance one after the other. 111 log.info( "Number of caches to monitor = " + caches.size() ); 112 113 caches.forEach((cacheName, cache) -> { 114 115 if (cache.getStatus() == CacheStatus.ERROR) 116 { 117 log.info( "Found LateralCacheNoWait in error, " + cacheName ); 118 119 final ITCPLateralCacheAttributes lca = 120 (ITCPLateralCacheAttributes) cache.getAuxiliaryCacheAttributes(); 121 122 // Get service instance 123 final ICacheServiceNonLocal<Object, Object> cacheService = 124 factory.getCSNLInstance(lca, cache.getElementSerializer()); 125 126 // If we can't fix them, just skip and re-try in the 127 // next round. 128 if (!(cacheService instanceof ZombieCacheServiceNonLocal)) 129 { 130 cache.fixCache(cacheService); 131 } 132 } 133 }); 134 } 135}