org.bboxdb.distribution.partitioner.SpacePartitionerCache Maven / Gradle / Ivy
/*******************************************************************************
*
* Copyright (C) 2015-2018 the BBoxDB project
*
* 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.bboxdb.distribution.partitioner;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.bboxdb.distribution.DistributionGroupConfigurationCache;
import org.bboxdb.distribution.TupleStoreConfigurationCache;
import org.bboxdb.distribution.region.DistributionRegionCallback;
import org.bboxdb.distribution.region.DistributionRegionIdMapper;
import org.bboxdb.distribution.zookeeper.NodeMutationHelper;
import org.bboxdb.distribution.zookeeper.ZookeeperClient;
import org.bboxdb.distribution.zookeeper.ZookeeperClientFactory;
import org.bboxdb.distribution.zookeeper.ZookeeperException;
import org.bboxdb.distribution.zookeeper.ZookeeperNodeNames;
import org.bboxdb.distribution.zookeeper.ZookeeperNotFoundException;
import org.bboxdb.misc.BBoxDBException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SpacePartitionerCache implements Watcher {
/**
* Mapping between the string group and the group object
*/
private final Map spacePartitioner;
/**
* The versions
*/
private final Map partitionerVersions;
/**
* The region mapper
*/
private final Map distributionRegionIdMapper;
/**
* The callbacks
*/
private final Map> callbacks;
/**
* The zookeeper adapter
*/
private final ZookeeperClient zookeeperClient;
/**
* The instance
*/
private static SpacePartitionerCache instance;
/**
* The Logger
*/
private final static Logger logger = LoggerFactory.getLogger(SpacePartitionerCache.class);
private SpacePartitionerCache() {
this.spacePartitioner = new HashMap<>();
this.distributionRegionIdMapper = new HashMap<>();
this.partitionerVersions = new HashMap<>();
this.callbacks = new HashMap<>();
this.zookeeperClient = ZookeeperClientFactory.getZookeeperClient();
}
public synchronized static SpacePartitionerCache getInstance() {
if(instance == null) {
instance = new SpacePartitionerCache();
}
return instance;
}
/**
* Get the distribution region for the given group name
* @param groupName
* @return
* @throws BBoxDBException
* @throws ZookeeperException
* @throws ZookeeperNotFoundException
*/
public synchronized SpacePartitioner getSpacePartitionerForGroupName(final String groupName)
throws BBoxDBException {
try {
if(! spacePartitioner.containsKey(groupName)) {
final String path = zookeeperClient
.getDistributionGroupAdapter().getDistributionGroupPath(groupName);
final long version = NodeMutationHelper
.getNodeMutationVersion(zookeeperClient, path, this);
// Create callback list
if(! callbacks.containsKey(groupName)) {
final Set callback = new CopyOnWriteArraySet<>();
callbacks.put(groupName, callback);
}
// Create region id mapper
if(! distributionRegionIdMapper.containsKey(groupName)) {
final DistributionRegionIdMapper mapper = new DistributionRegionIdMapper(groupName);
distributionRegionIdMapper.put(groupName, mapper);
}
final SpacePartitioner adapter = zookeeperClient
.getDistributionGroupAdapter().getSpaceparitioner(groupName,
callbacks.get(groupName), distributionRegionIdMapper.get(groupName));
partitionerVersions.put(groupName, version);
spacePartitioner.put(groupName, adapter);
}
return spacePartitioner.get(groupName);
} catch (ZookeeperException | ZookeeperNotFoundException e) {
throw new BBoxDBException(e);
}
}
/**
* Get all known distribution groups
* @return
*/
public synchronized Set getAllKnownDistributionGroups() {
return new HashSet<>(spacePartitioner.keySet());
}
/**
* Process changed on the registered distribution regions
*/
@Override
public void process(final WatchedEvent event) {
// Ignore events like connected and disconnected
if(event == null || event.getPath() == null) {
return;
}
final String path = event.getPath();
// Amount of distribution groups have changed
if(path.endsWith(ZookeeperNodeNames.NAME_NODE_VERSION)) {
logger.debug("===> Got event {}", event);
testGroupRecreatedNE();
} else {
logger.debug("===> Ignoring event for path: {}" , path);
}
}
/**
* Rescan for newly created distribution groups
*/
private void testGroupRecreatedNE() {
try {
testGroupRecreated();
} catch (Throwable e) {
logger.error("Got zookeeper exception", e);
}
}
/**
* Refresh the whole tree
* @throws ZookeeperException
*/
private void testGroupRecreated() throws ZookeeperException {
// Private copy to allow modifications
final Set knownPartitioner = new HashSet<>(spacePartitioner.keySet());
for(final String groupname : knownPartitioner) {
try {
final String path = zookeeperClient
.getDistributionGroupAdapter().getDistributionGroupPath(groupname);
final long zookeeperVersion
= NodeMutationHelper.getNodeMutationVersion(zookeeperClient, path, this);
final long memoryVersion = partitionerVersions.getOrDefault(groupname, 0l);
if(memoryVersion < zookeeperVersion) {
logger.info("Our space partitioner version is {}, zookeeper version is {}",
memoryVersion, zookeeperVersion);
resetSpacePartitioner(groupname);
getSpacePartitionerForGroupName(groupname);
}
} catch (ZookeeperNotFoundException e) {
logger.info("Version for {} not found, deleting in memory version", groupname);
resetSpacePartitioner(groupname);
} catch (BBoxDBException | ZookeeperException e) {
logger.error("Got exception while reading dgroup", e);
}
}
}
/**
* Reset the space partitioner
*
* @param groupname
*/
public void resetSpacePartitioner(final String groupname) {
final SpacePartitioner deletedSpacePartitioner = spacePartitioner.remove(groupname);
if(deletedSpacePartitioner != null) {
deletedSpacePartitioner.shutdown();
}
partitionerVersions.remove(groupname);
TupleStoreConfigurationCache.getInstance().clear();
DistributionGroupConfigurationCache.getInstance().clear();
distributionRegionIdMapper.get(groupname).clear();
}
@Override
protected Object clone() throws CloneNotSupportedException {
throw new CloneNotSupportedException("Unable to clone a singleton");
}
}