/*
* 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.geode.internal.admin;
import org.apache.geode.cache.AttributesFactory;
import org.apache.geode.cache.CacheListener;
import org.apache.geode.cache.ExpirationAction;
import org.apache.geode.cache.ExpirationAttributes;
import org.apache.geode.cache.Region;
import org.apache.geode.cache.RegionAttributes;
import org.apache.geode.cache.Scope;
import org.apache.geode.cache.util.CacheListenerAdapter;
import org.apache.geode.internal.cache.GemFireCacheImpl;
import org.apache.geode.internal.cache.InternalRegionArguments;
import org.apache.geode.internal.i18n.LocalizedStrings;
/**
* This is an admin (meta) region used by the client health monitoring service to publish the client
* health details to the cache-server.
*
*/
public class ClientHealthMonitoringRegion {
public final static String ADMIN_REGION_NAME = "__ADMIN_CLIENT_HEALTH_MONITORING__";
public final static int ADMIN_REGION_EXPIRY_INTERVAL = 20;
/**
* Instance for current cache
*
* @guarded.By ClientHealthMonitoringRegion.class
*/
static Region currentInstance;
/**
* This is an accessor method used to get the reference of this region. If this region is not yet
* initialized, then it attempts to create it.
*
* @param c the Cache we are currently using
* @return ClientHealthMonitoringRegion reference.
*/
public static synchronized Region getInstance(GemFireCacheImpl c) {
if (currentInstance != null && currentInstance.getCache() == c && !c.isClosed()) {
return currentInstance;
}
if (c == null || c.isClosed()) {
return null; // give up
}
initialize(c);
return currentInstance;
}
/**
* This method creates the client health monitoring region.
*
* @param cache The current GemFire Cache
* @guarded.By ClientHealthMonitoringRegion.class
*/
private static void initialize(GemFireCacheImpl cache) {
try {
AttributesFactory factory = new AttributesFactory();
factory.setScope(Scope.LOCAL);
factory.setEntryTimeToLive(
new ExpirationAttributes(ADMIN_REGION_EXPIRY_INTERVAL, ExpirationAction.DESTROY));
cache.getLogger().fine("ClientHealthMonitoringRegion, setting TTL for entry....");
factory.addCacheListener(prepareCacheListener());
factory.setStatisticsEnabled(true);
RegionAttributes regionAttrs = factory.create();
InternalRegionArguments internalArgs = new InternalRegionArguments();
internalArgs.setIsUsedForMetaRegion(true);
internalArgs.setIsUsedForPartitionedRegionAdmin(false);
currentInstance = cache.createVMRegion(ADMIN_REGION_NAME, regionAttrs, internalArgs);
} catch (Exception ex) {
cache.getLoggerI18n().error(
LocalizedStrings.ClientHealthMonitoringRegion_ERROR_WHILE_CREATING_AN_ADMIN_REGION, ex);
}
}
/**
* This method prepares a CacheListener, responsible for the cleanup of reference of admin region,
* upon the cache closure.
*
* @return CacheListener.
*/
private static CacheListener prepareCacheListener() {
return new CacheListenerAdapter() {
@Override
public void close() {
synchronized (ClientHealthMonitoringRegion.class) {
ClientHealthMonitoringRegion.currentInstance = null;
}
}
};
}
}