001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.procedure.flush;
019
020import java.io.IOException;
021import java.util.ArrayList;
022import java.util.Collection;
023import java.util.List;
024import java.util.concurrent.Callable;
025import java.util.concurrent.ExecutionException;
026import java.util.concurrent.ExecutorCompletionService;
027import java.util.concurrent.Future;
028import java.util.concurrent.ThreadPoolExecutor;
029import java.util.concurrent.TimeUnit;
030import org.apache.hadoop.conf.Configuration;
031import org.apache.hadoop.hbase.Abortable;
032import org.apache.hadoop.hbase.DroppedSnapshotException;
033import org.apache.hadoop.hbase.HBaseInterfaceAudience;
034import org.apache.hadoop.hbase.TableName;
035import org.apache.hadoop.hbase.errorhandling.ForeignException;
036import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
037import org.apache.hadoop.hbase.procedure.ProcedureMember;
038import org.apache.hadoop.hbase.procedure.ProcedureMemberRpcs;
039import org.apache.hadoop.hbase.procedure.RegionServerProcedureManager;
040import org.apache.hadoop.hbase.procedure.Subprocedure;
041import org.apache.hadoop.hbase.procedure.SubprocedureFactory;
042import org.apache.hadoop.hbase.procedure.ZKProcedureMemberRpcs;
043import org.apache.hadoop.hbase.regionserver.HRegion;
044import org.apache.hadoop.hbase.regionserver.HRegionServer;
045import org.apache.hadoop.hbase.regionserver.RegionServerServices;
046import org.apache.hadoop.hbase.util.Threads;
047import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
048import org.apache.yetus.audience.InterfaceAudience;
049import org.apache.zookeeper.KeeperException;
050import org.slf4j.Logger;
051import org.slf4j.LoggerFactory;
052
053import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;
054
055import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;
056
057/**
058 * This manager class handles flushing of the regions for table on a {@link HRegionServer}.
059 */
060@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
061public class RegionServerFlushTableProcedureManager extends RegionServerProcedureManager {
062  private static final Logger LOG =
063    LoggerFactory.getLogger(RegionServerFlushTableProcedureManager.class);
064
065  private static final String CONCURENT_FLUSH_TASKS_KEY =
066    "hbase.flush.procedure.region.concurrentTasks";
067  private static final int DEFAULT_CONCURRENT_FLUSH_TASKS = 3;
068
069  public static final String FLUSH_REQUEST_THREADS_KEY =
070    "hbase.flush.procedure.region.pool.threads";
071  public static final int FLUSH_REQUEST_THREADS_DEFAULT = 10;
072
073  public static final String FLUSH_TIMEOUT_MILLIS_KEY = "hbase.flush.procedure.region.timeout";
074  public static final long FLUSH_TIMEOUT_MILLIS_DEFAULT = 60000;
075
076  public static final String FLUSH_REQUEST_WAKE_MILLIS_KEY =
077    "hbase.flush.procedure.region.wakefrequency";
078  private static final long FLUSH_REQUEST_WAKE_MILLIS_DEFAULT = 500;
079
080  private RegionServerServices rss;
081  private ProcedureMemberRpcs memberRpcs;
082  private ProcedureMember member;
083
084  /**
085   * Exposed for testing.
086   * @param conf       HBase configuration.
087   * @param server     region server.
088   * @param memberRpc  use specified memberRpc instance
089   * @param procMember use specified ProcedureMember
090   */
091  RegionServerFlushTableProcedureManager(Configuration conf, HRegionServer server,
092    ProcedureMemberRpcs memberRpc, ProcedureMember procMember) {
093    this.rss = server;
094    this.memberRpcs = memberRpc;
095    this.member = procMember;
096  }
097
098  public RegionServerFlushTableProcedureManager() {
099  }
100
101  /**
102   * Start accepting flush table requests.
103   */
104  @Override
105  public void start() {
106    LOG.debug("Start region server flush procedure manager " + rss.getServerName().toString());
107    this.memberRpcs.start(rss.getServerName().toString(), member);
108  }
109
110  /**
111   * Close <tt>this</tt> and all running tasks
112   * @param force forcefully stop all running tasks
113   */
114  @Override
115  public void stop(boolean force) throws IOException {
116    String mode = force ? "abruptly" : "gracefully";
117    LOG.info("Stopping region server flush procedure manager " + mode + ".");
118
119    try {
120      this.member.close();
121    } finally {
122      this.memberRpcs.close();
123    }
124  }
125
126  /**
127   * If in a running state, creates the specified subprocedure to flush table regions. Because this
128   * gets the local list of regions to flush and not the set the master had, there is a possibility
129   * of a race where regions may be missed.
130   * @return Subprocedure to submit to the ProcedureMember.
131   */
132  public Subprocedure buildSubprocedure(String table, String family) {
133
134    // don't run the subprocedure if the parent is stop(ping)
135    if (rss.isStopping() || rss.isStopped()) {
136      throw new IllegalStateException("Can't start flush region subprocedure on RS: "
137        + rss.getServerName() + ", because stopping/stopped!");
138    }
139
140    // check to see if this server is hosting any regions for the table
141    List<HRegion> involvedRegions;
142    try {
143      involvedRegions = getRegionsToFlush(table);
144    } catch (IOException e1) {
145      throw new IllegalStateException("Failed to figure out if there is region to flush.", e1);
146    }
147
148    // We need to run the subprocedure even if we have no relevant regions. The coordinator
149    // expects participation in the procedure and without sending message the master procedure
150    // will hang and fail.
151
152    LOG.debug("Launching subprocedure to flush regions for " + table);
153    ForeignExceptionDispatcher exnDispatcher = new ForeignExceptionDispatcher(table);
154    Configuration conf = rss.getConfiguration();
155    long timeoutMillis = conf.getLong(FLUSH_TIMEOUT_MILLIS_KEY, FLUSH_TIMEOUT_MILLIS_DEFAULT);
156    long wakeMillis =
157      conf.getLong(FLUSH_REQUEST_WAKE_MILLIS_KEY, FLUSH_REQUEST_WAKE_MILLIS_DEFAULT);
158
159    FlushTableSubprocedurePool taskManager =
160      new FlushTableSubprocedurePool(rss.getServerName().toString(), conf, rss);
161    return new FlushTableSubprocedure(member, exnDispatcher, wakeMillis, timeoutMillis,
162      involvedRegions, table, family, taskManager);
163  }
164
165  /**
166   * Get the list of regions to flush for the table on this server It is possible that if a region
167   * moves somewhere between the calls we'll miss the region.
168   * @return the list of online regions. Empty list is returned if no regions.
169   */
170  private List<HRegion> getRegionsToFlush(String table) throws IOException {
171    return (List<HRegion>) rss.getRegions(TableName.valueOf(table));
172  }
173
174  public class FlushTableSubprocedureBuilder implements SubprocedureFactory {
175
176    @Override
177    public Subprocedure buildSubprocedure(String name, byte[] data) {
178      String family = null;
179      // Currently we do not put other data except family, so it is ok to
180      // judge by length that if family was specified
181      if (data.length > 0) {
182        try {
183          HBaseProtos.NameStringPair nsp = HBaseProtos.NameStringPair.parseFrom(data);
184          family = nsp.getValue();
185        } catch (Exception e) {
186          LOG.error("fail to get family by parsing from data", e);
187        }
188      }
189      // The name of the procedure instance from the master is the table name.
190      return RegionServerFlushTableProcedureManager.this.buildSubprocedure(name, family);
191    }
192
193  }
194
195  /**
196   * We use the FlushTableSubprocedurePool, a class specific thread pool instead of
197   * {@link org.apache.hadoop.hbase.executor.ExecutorService}. It uses a
198   * {@link java.util.concurrent.ExecutorCompletionService} which provides queuing of completed
199   * tasks which lets us efficiently cancel pending tasks upon the earliest operation failures.
200   */
201  static class FlushTableSubprocedurePool {
202    private final Abortable abortable;
203    private final ExecutorCompletionService<Void> taskPool;
204    private final ThreadPoolExecutor executor;
205    private volatile boolean stopped;
206    private final List<Future<Void>> futures = new ArrayList<>();
207    private final String name;
208
209    FlushTableSubprocedurePool(String name, Configuration conf, Abortable abortable) {
210      this.abortable = abortable;
211      // configure the executor service
212      long keepAlive = conf.getLong(RegionServerFlushTableProcedureManager.FLUSH_TIMEOUT_MILLIS_KEY,
213        RegionServerFlushTableProcedureManager.FLUSH_TIMEOUT_MILLIS_DEFAULT);
214      int threads = conf.getInt(CONCURENT_FLUSH_TASKS_KEY, DEFAULT_CONCURRENT_FLUSH_TASKS);
215      this.name = name;
216      executor = Threads.getBoundedCachedThreadPool(threads, keepAlive, TimeUnit.MILLISECONDS,
217        new ThreadFactoryBuilder().setNameFormat("rs(" + name + ")-flush-proc-pool-%d")
218          .setDaemon(true).setUncaughtExceptionHandler(Threads.LOGGING_EXCEPTION_HANDLER).build());
219      taskPool = new ExecutorCompletionService<>(executor);
220    }
221
222    boolean hasTasks() {
223      return futures.size() != 0;
224    }
225
226    /**
227     * Submit a task to the pool. NOTE: all must be submitted before you can safely
228     * {@link #waitForOutstandingTasks()}.
229     */
230    void submitTask(final Callable<Void> task) {
231      Future<Void> f = this.taskPool.submit(task);
232      futures.add(f);
233    }
234
235    /**
236     * Wait for all of the currently outstanding tasks submitted via {@link #submitTask(Callable)}.
237     * This *must* be called after all tasks are submitted via submitTask.
238     * @return <tt>true</tt> on success, <tt>false</tt> otherwise
239     */
240    boolean waitForOutstandingTasks() throws ForeignException, InterruptedException {
241      LOG.debug("Waiting for local region flush to finish.");
242
243      int sz = futures.size();
244      try {
245        // Using the completion service to process the futures.
246        for (int i = 0; i < sz; i++) {
247          Future<Void> f = taskPool.take();
248          f.get();
249          if (!futures.remove(f)) {
250            LOG.warn("unexpected future" + f);
251          }
252          LOG.debug("Completed " + (i + 1) + "/" + sz + " local region flush tasks.");
253        }
254        LOG.debug("Completed " + sz + " local region flush tasks.");
255        return true;
256      } catch (InterruptedException e) {
257        LOG.warn("Got InterruptedException in FlushSubprocedurePool", e);
258        if (!stopped) {
259          Thread.currentThread().interrupt();
260          throw new ForeignException("FlushSubprocedurePool", e);
261        }
262        // we are stopped so we can just exit.
263      } catch (ExecutionException e) {
264        Throwable cause = e.getCause();
265        if (cause instanceof ForeignException) {
266          LOG.warn("Rethrowing ForeignException from FlushSubprocedurePool", e);
267          throw (ForeignException) e.getCause();
268        } else if (cause instanceof DroppedSnapshotException) {
269          // we have to abort the region server according to contract of flush
270          abortable.abort("Received DroppedSnapshotException, aborting", cause);
271        }
272        LOG.warn("Got Exception in FlushSubprocedurePool", e);
273        throw new ForeignException(name, e.getCause());
274      } finally {
275        cancelTasks();
276      }
277      return false;
278    }
279
280    /**
281     * This attempts to cancel out all pending and in progress tasks. Does not interrupt the running
282     * tasks itself. An ongoing HRegion.flush() should not be interrupted (see HBASE-13877).
283     */
284    void cancelTasks() throws InterruptedException {
285      Collection<Future<Void>> tasks = futures;
286      LOG.debug("cancelling " + tasks.size() + " flush region tasks " + name);
287      for (Future<Void> f : tasks) {
288        f.cancel(false);
289      }
290
291      // evict remaining tasks and futures from taskPool.
292      futures.clear();
293      while (taskPool.poll() != null) {
294      }
295      stop();
296    }
297
298    /**
299     * Gracefully shutdown the thread pool. An ongoing HRegion.flush() should not be interrupted
300     * (see HBASE-13877)
301     */
302    void stop() {
303      if (this.stopped) return;
304
305      this.stopped = true;
306      this.executor.shutdown();
307    }
308  }
309
310  /**
311   * Initialize this region server flush procedure manager Uses a zookeeper based member controller.
312   * @param rss region server
313   * @throws KeeperException if the zookeeper cannot be reached
314   */
315  @Override
316  public void initialize(RegionServerServices rss) throws KeeperException {
317    this.rss = rss;
318    ZKWatcher zkw = rss.getZooKeeper();
319    this.memberRpcs = new ZKProcedureMemberRpcs(zkw,
320      MasterFlushTableProcedureManager.FLUSH_TABLE_PROCEDURE_SIGNATURE);
321
322    Configuration conf = rss.getConfiguration();
323    long keepAlive = conf.getLong(FLUSH_TIMEOUT_MILLIS_KEY, FLUSH_TIMEOUT_MILLIS_DEFAULT);
324    int opThreads = conf.getInt(FLUSH_REQUEST_THREADS_KEY, FLUSH_REQUEST_THREADS_DEFAULT);
325
326    // create the actual flush table procedure member
327    ThreadPoolExecutor pool =
328      ProcedureMember.defaultPool(rss.getServerName().toString(), opThreads, keepAlive);
329    this.member = new ProcedureMember(memberRpcs, pool, new FlushTableSubprocedureBuilder());
330  }
331
332  @Override
333  public String getProcedureSignature() {
334    return MasterFlushTableProcedureManager.FLUSH_TABLE_PROCEDURE_SIGNATURE;
335  }
336
337}