/**
*
* 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;
import java.io.Closeable;
import java.io.IOException;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;
import org.apache.hadoop.hbase.wal.WAL;
import org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.HasThread;
import org.apache.hadoop.ipc.RemoteException;
import com.google.common.annotations.VisibleForTesting;
/**
* Runs periodically to determine if the WAL should be rolled.
*
* NOTE: This class extends Thread rather than Chore because the sleep time
* can be interrupted when there is something to do, rather than the Chore
* sleep time which is invariant.
*
* TODO: change to a pool of threads
*/
@InterfaceAudience.Private
@VisibleForTesting
public class LogRoller extends HasThread implements Closeable {
private static final Log LOG = LogFactory.getLog(LogRoller.class);
private final ReentrantLock rollLock = new ReentrantLock();
private final AtomicBoolean rollLog = new AtomicBoolean(false);
private final ConcurrentHashMap<WAL, Boolean> walNeedsRoll = new ConcurrentHashMap<>();
private final Server server;
protected final RegionServerServices services;
private volatile long lastrolltime = System.currentTimeMillis();
// Period to roll log.
private final long rollperiod;
private final int threadWakeFrequency;
private volatile boolean running = true;
public void addWAL(final WAL wal) {
if (null == walNeedsRoll.putIfAbsent(wal, Boolean.FALSE)) {
wal.registerWALActionsListener(new WALActionsListener.Base() {
@Override
public void logRollRequested(boolean lowReplicas) {
walNeedsRoll.put(wal, Boolean.TRUE);
// TODO logs will contend with each other here, replace with e.g. DelayedQueue
synchronized(rollLog) {
rollLog.set(true);
rollLog.notifyAll();
}
}
});
}
}
public void requestRollAll() {
for (WAL wal : walNeedsRoll.keySet()) {
walNeedsRoll.put(wal, Boolean.TRUE);
}
synchronized(rollLog) {
rollLog.set(true);
rollLog.notifyAll();
}
}
/** @param server */
public LogRoller(final Server server, final RegionServerServices services) {
super("LogRoller");
this.server = server;
this.services = services;
this.rollperiod = this.server.getConfiguration().
getLong("hbase.regionserver.logroll.period", 3600000);
this.threadWakeFrequency = this.server.getConfiguration().
getInt(HConstants.THREAD_WAKE_FREQUENCY, 10 * 1000);
}
@Override
public void interrupt() {
// Wake up if we are waiting on rollLog. For tests.
synchronized (rollLog) {
this.rollLog.notify();
}
super.interrupt();
}
@Override
public void run() {
while (running) {
long now = System.currentTimeMillis();
boolean periodic = false;
if (!rollLog.get()) {
periodic = (now - this.lastrolltime) > this.rollperiod;
if (!periodic) {
synchronized (rollLog) {
try {
if (!rollLog.get()) {
rollLog.wait(this.threadWakeFrequency);
}
} catch (InterruptedException e) {
// Fall through
}
}
continue;
}
// Time for periodic roll
if (LOG.isDebugEnabled()) {
LOG.debug("Wal roll period " + this.rollperiod + "ms elapsed");
}
} else if (LOG.isDebugEnabled()) {
LOG.debug("WAL roll requested");
}
rollLock.lock(); // FindBugs UL_UNRELEASED_LOCK_EXCEPTION_PATH
try {
this.lastrolltime = now;
for (Entry<WAL, Boolean> entry : walNeedsRoll.entrySet()) {
final WAL wal = entry.getKey();
// Force the roll if the logroll.period is elapsed or if a roll was requested.
// The returned value is an array of actual region names.
final byte [][] regionsToFlush = wal.rollWriter(periodic ||
entry.getValue().booleanValue());
walNeedsRoll.put(wal, Boolean.FALSE);
if (regionsToFlush != null) {
for (byte [] r: regionsToFlush) scheduleFlush(r);
}
}
} catch (FailedLogCloseException e) {
server.abort("Failed log close in log roller", e);
} catch (java.net.ConnectException e) {
server.abort("Failed log close in log roller", e);
} catch (IOException ex) {
// Abort if we get here. We probably won't recover an IOE. HBASE-1132
server.abort("IOE in log roller",
ex instanceof RemoteException ? ((RemoteException) ex).unwrapRemoteException() : ex);
} catch (Exception ex) {
LOG.error("Log rolling failed", ex);
server.abort("Log rolling failed", ex);
} finally {
try {
rollLog.set(false);
} finally {
rollLock.unlock();
}
}
}
LOG.info("LogRoller exiting.");
}
/**
* @param encodedRegionName Encoded name of region to flush.
*/
private void scheduleFlush(final byte [] encodedRegionName) {
boolean scheduled = false;
Region r = this.services.getFromOnlineRegions(Bytes.toString(encodedRegionName));
FlushRequester requester = null;
if (r != null) {
requester = this.services.getFlushRequester();
if (requester != null) {
// force flushing all stores to clean old logs
requester.requestFlush(r, true);
scheduled = true;
}
}
if (!scheduled) {
LOG.warn("Failed to schedule flush of " +
Bytes.toString(encodedRegionName) + ", region=" + r + ", requester=" +
requester);
}
}
/**
* For testing only
* @return true if all WAL roll finished
*/
@VisibleForTesting
public boolean walRollFinished() {
for (boolean needRoll : walNeedsRoll.values()) {
if (needRoll) {
return false;
}
}
return true;
}
@Override
public void close() {
running = false;
interrupt();
}
}