veghlaci05 commented on code in PR #3303: URL: https://github.com/apache/hive/pull/3303#discussion_r887866285
########## ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/CompactionHeartbeatService.java: ########## @@ -0,0 +1,256 @@ +/* + * 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.hadoop.hive.ql.txn.compactor; + +import org.apache.commons.pool2.BasePooledObjectFactory; +import org.apache.commons.pool2.ObjectPool; +import org.apache.commons.pool2.PooledObject; +import org.apache.commons.pool2.impl.DefaultPooledObject; +import org.apache.commons.pool2.impl.GenericObjectPool; +import org.apache.commons.pool2.impl.GenericObjectPoolConfig; +import org.apache.hadoop.hive.conf.HiveConf; +import org.apache.hadoop.hive.metastore.HiveMetaStoreUtils; +import org.apache.hadoop.hive.metastore.IMetaStoreClient; +import org.apache.hadoop.hive.metastore.conf.MetastoreConf; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.NoSuchElementException; +import java.util.Objects; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; + +/** + * Singleton service responsible for heartbeating the compaction transactions. + */ +class CompactionHeartbeatService { + + + private static final Logger LOG = LoggerFactory.getLogger(CompactionHeartbeatService.class); + + private static volatile CompactionHeartbeatService INSTANCE; + + /** + * Return the singleton instance of this class. + * @param conf The {@link HiveConf} used to create the service. Used only during the firsst call + * @return Returns the singleton {@link CompactionHeartbeatService} + * @throws IllegalStateException Thrown when the service has already been shut down. + */ + static CompactionHeartbeatService getInstance(HiveConf conf) { + if (INSTANCE == null) { + synchronized (CompactionHeartbeatService.class) { + if (INSTANCE == null) { + LOG.debug("Initializing compaction txn heartbeater service."); + INSTANCE = new CompactionHeartbeatService(conf); + Runtime.getRuntime().addShutdownHook(new Thread(() -> { + try { + INSTANCE.shutdown(); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + } + })); + } + } + } + if (INSTANCE.heartbeatExecutor.isShutdown()) { + throw new IllegalStateException("The CompactionHeartbeatService is already shut down!"); + } + return INSTANCE; + } + + private final ScheduledExecutorService heartbeatExecutor; + private final ObjectPool<IMetaStoreClient> clientPool; + private final long initialDelay; + private final long period; + private final ConcurrentHashMap<Long, TaskWrapper> tasks = new ConcurrentHashMap<>(30); Review Comment: The map is used in the `startHeartbeat()` and `stopHeartBeat()` methods which can be called concurrently if there a re multiple worker threads configured. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
