| /* |
| * 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.client; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.util.HashSet; |
| import java.util.Set; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.TimeUnit; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.ServerName; |
| import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.hbase.thirdparty.com.google.common.base.Preconditions; |
| import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder; |
| |
| import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ClientMetaService; |
| |
| /** |
| * Thread safe utility that keeps master end points used by {@link MasterRegistry} up to date. This |
| * uses the RPC {@link ClientMetaService#getMasters} to fetch the latest list of registered masters. |
| * By default the refresh happens periodically (configured via |
| * {@link #PERIODIC_REFRESH_INTERVAL_SECS}). The refresh can also be triggered on demand via |
| * {@link #refreshNow()}. To prevent a flood of on-demand refreshes we expect that any attempts two |
| * should be spaced at least {@link #MIN_SECS_BETWEEN_REFRESHES} seconds apart. |
| */ |
| @InterfaceAudience.Private |
| public class MasterAddressRefresher implements Closeable { |
| private static final Logger LOG = LoggerFactory.getLogger(MasterAddressRefresher.class); |
| public static final String PERIODIC_REFRESH_INTERVAL_SECS = |
| "hbase.client.master_registry.refresh_interval_secs"; |
| private static final int PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT = 300; |
| public static final String MIN_SECS_BETWEEN_REFRESHES = |
| "hbase.client.master_registry.min_secs_between_refreshes"; |
| private static final int MIN_SECS_BETWEEN_REFRESHES_DEFAULT = 60; |
| |
| private final ExecutorService pool; |
| private final MasterRegistry registry; |
| private final long periodicRefreshMs; |
| private final long timeBetweenRefreshesMs; |
| private final Object refreshMasters = new Object(); |
| |
| @Override |
| public void close() { |
| pool.shutdownNow(); |
| } |
| |
| /** |
| * Thread that refreshes the master end points until it is interrupted via {@link #close()}. |
| * Multiple callers attempting to refresh at the same time synchronize on {@link #refreshMasters}. |
| */ |
| private class RefreshThread implements Runnable { |
| @Override |
| public void run() { |
| long lastRpcTs = 0; |
| while (!Thread.interrupted()) { |
| try { |
| // Spurious wake ups are okay, worst case we make an extra RPC call to refresh. We won't |
| // have duplicate refreshes because once the thread is past the wait(), notify()s are |
| // ignored until the thread is back to the waiting state. |
| synchronized (refreshMasters) { |
| refreshMasters.wait(periodicRefreshMs); |
| } |
| long currentTs = EnvironmentEdgeManager.currentTime(); |
| if (lastRpcTs != 0 && currentTs - lastRpcTs <= timeBetweenRefreshesMs) { |
| continue; |
| } |
| lastRpcTs = currentTs; |
| LOG.debug("Attempting to refresh master address end points."); |
| Set<ServerName> newMasters = new HashSet<>(registry.getMasters().get()); |
| registry.populateMasterStubs(newMasters); |
| LOG.debug("Finished refreshing master end points. {}", newMasters); |
| } catch (InterruptedException e) { |
| LOG.debug("Interrupted during wait, aborting refresh-masters-thread.", e); |
| break; |
| } catch (ExecutionException | IOException e) { |
| LOG.debug("Error populating latest list of masters.", e); |
| } |
| } |
| LOG.info("Master end point refresher loop exited."); |
| } |
| } |
| |
| MasterAddressRefresher(Configuration conf, MasterRegistry registry) { |
| pool = Executors.newSingleThreadExecutor(new ThreadFactoryBuilder() |
| .setNameFormat("master-registry-refresh-end-points").setDaemon(true).build()); |
| periodicRefreshMs = TimeUnit.SECONDS.toMillis(conf.getLong(PERIODIC_REFRESH_INTERVAL_SECS, |
| PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT)); |
| timeBetweenRefreshesMs = TimeUnit.SECONDS.toMillis(conf.getLong(MIN_SECS_BETWEEN_REFRESHES, |
| MIN_SECS_BETWEEN_REFRESHES_DEFAULT)); |
| Preconditions.checkArgument(periodicRefreshMs > 0); |
| Preconditions.checkArgument(timeBetweenRefreshesMs < periodicRefreshMs); |
| this.registry = registry; |
| pool.submit(new RefreshThread()); |
| } |
| |
| /** |
| * Notifies the refresher thread to refresh the configuration. This does not guarantee a refresh. |
| * See class comment for details. |
| */ |
| void refreshNow() { |
| synchronized (refreshMasters) { |
| refreshMasters.notify(); |
| } |
| } |
| } |