ndimiduk commented on a change in pull request #2454: URL: https://github.com/apache/hbase/pull/2454#discussion_r501290825
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/RegionNormalizerManager.java ########## @@ -0,0 +1,178 @@ +/* + * 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.hbase.master.normalizer; + +import edu.umd.cs.findbugs.annotations.NonNull; +import edu.umd.cs.findbugs.annotations.Nullable; +import java.util.List; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import org.apache.hadoop.hbase.TableName; +import org.apache.hadoop.hbase.zookeeper.RegionNormalizerTracker; +import org.apache.yetus.audience.InterfaceAudience; +import org.apache.zookeeper.KeeperException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder; + +/** + * This class encapsulates the details of the {@link RegionNormalizer} subsystem. + */ +@InterfaceAudience.Private +public class RegionNormalizerManager { + private static final Logger LOG = LoggerFactory.getLogger(RegionNormalizerManager.class); + + private final RegionNormalizerTracker regionNormalizerTracker; + private final RegionNormalizerChore regionNormalizerChore; + private final RegionNormalizerWorkQueue<TableName> workQueue; + private final RegionNormalizerWorker worker; + private final ExecutorService pool; + + private final Object startStopLock = new Object(); + private boolean started = false; + private boolean stopped = false; + + public RegionNormalizerManager( + @NonNull final RegionNormalizerTracker regionNormalizerTracker, + @Nullable final RegionNormalizerChore regionNormalizerChore, + @Nullable final RegionNormalizerWorkQueue<TableName> workQueue, + @Nullable final RegionNormalizerWorker worker + ) { + this.regionNormalizerTracker = regionNormalizerTracker; + this.regionNormalizerChore = regionNormalizerChore; + this.workQueue = workQueue; + this.worker = worker; + this.pool = Executors.newSingleThreadExecutor(new ThreadFactoryBuilder() + .setDaemon(true) + .setNameFormat("normalizer-worker-%d") + .setUncaughtExceptionHandler( + (thread, throwable) -> + LOG.error("Uncaught exception, worker thread likely terminated.", throwable)) + .build()); + } + + public void start() { + if (started) { + return; + } + synchronized (startStopLock) { + if (started) { + return; + } + regionNormalizerTracker.start(); + if (worker != null) { + // worker will be null when master is in maintenance mode. + pool.submit(worker); + } + started = true; + } + } + + public void stop() { + if (!started) { + throw new IllegalStateException("calling `stop` without first calling `start`."); + } + if (stopped) { Review comment: Here's a WIP to move over to Guava Service. Let me know if you think it's worth the effort. https://github.com/ndimiduk/hbase/commit/7d7bdb4f2affba2f4ff82871ec48c7d850538a3f ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
