org.apache.hadoop.hbase.regionserver.handler.HLogSplitterHandler.java Source code

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Here is the source code for org.apache.hadoop.hbase.regionserver.handler.HLogSplitterHandler.java

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/**
 *
 * 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.regionserver.handler;

import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

import org.apache.commons.lang.mutable.MutableInt;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.SplitLogCounters;
import org.apache.hadoop.hbase.SplitLogTask;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.SplitLogManager;
import org.apache.hadoop.hbase.regionserver.SplitLogWorker.TaskExecutor;
import org.apache.hadoop.hbase.regionserver.SplitLogWorker.TaskExecutor.Status;
import org.apache.hadoop.hbase.util.CancelableProgressable;
import org.apache.hadoop.hbase.zookeeper.ZKSplitLog;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.zookeeper.KeeperException;

/**
 * Handles log splitting a wal
 */
@InterfaceAudience.Private
public class HLogSplitterHandler extends EventHandler {
    private static final Log LOG = LogFactory.getLog(HLogSplitterHandler.class);
    private final ServerName serverName;
    private final String curTask;
    private final String wal;
    private final ZooKeeperWatcher zkw;
    private final CancelableProgressable reporter;
    private final AtomicInteger inProgressTasks;
    private final MutableInt curTaskZKVersion;
    private final TaskExecutor splitTaskExecutor;

    public HLogSplitterHandler(final Server server, String curTask, final MutableInt curTaskZKVersion,
            CancelableProgressable reporter, AtomicInteger inProgressTasks, TaskExecutor splitTaskExecutor) {
        super(server, EventType.RS_LOG_REPLAY);
        this.curTask = curTask;
        this.wal = ZKSplitLog.getFileName(curTask);
        this.reporter = reporter;
        this.inProgressTasks = inProgressTasks;
        this.inProgressTasks.incrementAndGet();
        this.serverName = server.getServerName();
        this.zkw = server.getZooKeeper();
        this.curTaskZKVersion = curTaskZKVersion;
        this.splitTaskExecutor = splitTaskExecutor;
    }

    @Override
    public void process() throws IOException {
        long startTime = System.currentTimeMillis();
        try {
            Status status = this.splitTaskExecutor.exec(wal, reporter);
            switch (status) {
            case DONE:
                endTask(zkw, new SplitLogTask.Done(this.serverName), SplitLogCounters.tot_wkr_task_done, curTask,
                        curTaskZKVersion.intValue());
                break;
            case PREEMPTED:
                SplitLogCounters.tot_wkr_preempt_task.incrementAndGet();
                LOG.warn("task execution prempted " + wal);
                break;
            case ERR:
                if (server != null && !server.isStopped()) {
                    endTask(zkw, new SplitLogTask.Err(this.serverName), SplitLogCounters.tot_wkr_task_err, curTask,
                            curTaskZKVersion.intValue());
                    break;
                }
                // if the RS is exiting then there is probably a tons of stuff
                // that can go wrong. Resign instead of signaling error.
                //$FALL-THROUGH$
            case RESIGNED:
                if (server != null && server.isStopped()) {
                    LOG.info("task execution interrupted because worker is exiting " + curTask);
                }
                endTask(zkw, new SplitLogTask.Resigned(this.serverName), SplitLogCounters.tot_wkr_task_resigned,
                        curTask, curTaskZKVersion.intValue());
                break;
            }
        } finally {
            LOG.info("worker " + serverName + " done with task " + curTask + " in "
                    + (System.currentTimeMillis() - startTime) + "ms");
            this.inProgressTasks.decrementAndGet();
        }
    }

    /**
     * endTask() can fail and the only way to recover out of it is for the
     * {@link SplitLogManager} to timeout the task node.
     * @param slt
     * @param ctr
     */
    public static void endTask(ZooKeeperWatcher zkw, SplitLogTask slt, AtomicLong ctr, String task,
            int taskZKVersion) {
        try {
            if (ZKUtil.setData(zkw, task, slt.toByteArray(), taskZKVersion)) {
                LOG.info("successfully transitioned task " + task + " to final state " + slt);
                ctr.incrementAndGet();
                return;
            }
            LOG.warn("failed to transistion task " + task + " to end state " + slt
                    + " because of version mismatch ");
        } catch (KeeperException.BadVersionException bve) {
            LOG.warn("transisition task " + task + " to " + slt + " failed because of version mismatch", bve);
        } catch (KeeperException.NoNodeException e) {
            LOG.fatal("logic error - end task " + task + " " + slt + " failed because task doesn't exist", e);
        } catch (KeeperException e) {
            LOG.warn("failed to end task, " + task + " " + slt, e);
        }
        SplitLogCounters.tot_wkr_final_transition_failed.incrementAndGet();
    }
}