/**
*
* 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();
}
}