/**
*
* 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.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.RemoteExceptionHandler;
import org.apache.hadoop.hbase.regionserver.compactions.CompactionContext;
import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.util.StringUtils;
import com.google.common.base.Preconditions;
/**
* Compact region on request and then run split if appropriate
*/
@InterfaceAudience.Private
public class CompactSplitThread implements CompactionRequestor {
static final Log LOG = LogFactory.getLog(CompactSplitThread.class);
private final HRegionServer server;
private final Configuration conf;
private final ThreadPoolExecutor largeCompactions;
private final ThreadPoolExecutor smallCompactions;
private final ThreadPoolExecutor splits;
private final ThreadPoolExecutor mergePool;
/**
* Splitting should not take place if the total number of regions exceed this.
* This is not a hard limit to the number of regions but it is a guideline to
* stop splitting after number of online regions is greater than this.
*/
private int regionSplitLimit;
/** @param server */
CompactSplitThread(HRegionServer server) {
super();
this.server = server;
this.conf = server.getConfiguration();
this.regionSplitLimit = conf.getInt("hbase.regionserver.regionSplitLimit",
Integer.MAX_VALUE);
int largeThreads = Math.max(1, conf.getInt(
"hbase.regionserver.thread.compaction.large", 1));
int smallThreads = conf.getInt(
"hbase.regionserver.thread.compaction.small", 1);
int splitThreads = conf.getInt("hbase.regionserver.thread.split", 1);
// if we have throttle threads, make sure the user also specified size
Preconditions.checkArgument(largeThreads > 0 && smallThreads > 0);
final String n = Thread.currentThread().getName();
this.largeCompactions = new ThreadPoolExecutor(largeThreads, largeThreads,
60, TimeUnit.SECONDS, new PriorityBlockingQueue<Runnable>(),
new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r);
t.setName(n + "-largeCompactions-" + System.currentTimeMillis());
return t;
}
});
this.largeCompactions.setRejectedExecutionHandler(new Rejection());
this.smallCompactions = new ThreadPoolExecutor(smallThreads, smallThreads,
60, TimeUnit.SECONDS, new PriorityBlockingQueue<Runnable>(),
new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r);
t.setName(n + "-smallCompactions-" + System.currentTimeMillis());
return t;
}
});
this.smallCompactions
.setRejectedExecutionHandler(new Rejection());
this.splits = (ThreadPoolExecutor)
Executors.newFixedThreadPool(splitThreads,
new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r);
t.setName(n + "-splits-" + System.currentTimeMillis());
return t;
}
});
int mergeThreads = conf.getInt("hbase.regionserver.thread.merge", 1);
this.mergePool = (ThreadPoolExecutor) Executors.newFixedThreadPool(
mergeThreads, new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r);
t.setName(n + "-merges-" + System.currentTimeMillis());
return t;
}
});
}
@Override
public String toString() {
return "compaction_queue=("
+ largeCompactions.getQueue().size() + ":"
+ smallCompactions.getQueue().size() + ")"
+ ", split_queue=" + splits.getQueue().size()
+ ", merge_queue=" + mergePool.getQueue().size();
}
public String dumpQueue() {
StringBuffer queueLists = new StringBuffer();
queueLists.append("Compaction/Split Queue dump:\n");
queueLists.append(" LargeCompation Queue:\n");
BlockingQueue<Runnable> lq = largeCompactions.getQueue();
Iterator it = lq.iterator();
while(it.hasNext()){
queueLists.append(" "+it.next().toString());
queueLists.append("\n");
}
if( smallCompactions != null ){
queueLists.append("\n");
queueLists.append(" SmallCompation Queue:\n");
lq = smallCompactions.getQueue();
it = lq.iterator();
while(it.hasNext()){
queueLists.append(" "+it.next().toString());
queueLists.append("\n");
}
}
queueLists.append("\n");
queueLists.append(" Split Queue:\n");
lq = splits.getQueue();
it = lq.iterator();
while(it.hasNext()){
queueLists.append(" "+it.next().toString());
queueLists.append("\n");
}
queueLists.append("\n");
queueLists.append(" Region Merge Queue:\n");
lq = mergePool.getQueue();
it = lq.iterator();
while (it.hasNext()) {
queueLists.append(" " + it.next().toString());
queueLists.append("\n");
}
return queueLists.toString();
}
public synchronized void requestRegionsMerge(final HRegion a,
final HRegion b, final boolean forcible) {
try {
mergePool.execute(new RegionMergeRequest(a, b, this.server, forcible));
if (LOG.isDebugEnabled()) {
LOG.debug("Region merge requested for " + a + "," + b + ", forcible="
+ forcible + ". " + this);
}
} catch (RejectedExecutionException ree) {
LOG.warn("Could not execute merge for " + a + "," + b + ", forcible="
+ forcible, ree);
}
}
public synchronized boolean requestSplit(final HRegion r) {
// don't split regions that are blocking
if (shouldSplitRegion() && r.getCompactPriority() >= Store.PRIORITY_USER) {
byte[] midKey = r.checkSplit();
if (midKey != null) {
requestSplit(r, midKey);
return true;
}
}
return false;
}
public synchronized void requestSplit(final HRegion r, byte[] midKey) {
if (midKey == null) {
LOG.debug("Region " + r.getRegionNameAsString() +
" not splittable because midkey=null");
return;
}
try {
this.splits.execute(new SplitRequest(r, midKey, this.server));
if (LOG.isDebugEnabled()) {
LOG.debug("Split requested for " + r + ". " + this);
}
} catch (RejectedExecutionException ree) {
LOG.info("Could not execute split for " + r, ree);
}
}
@Override
public synchronized List<CompactionRequest> requestCompaction(final HRegion r, final String why)
throws IOException {
return requestCompaction(r, why, null);
}
@Override
public synchronized List<CompactionRequest> requestCompaction(final HRegion r, final String why,
List<Pair<CompactionRequest, Store>> requests) throws IOException {
return requestCompaction(r, why, Store.NO_PRIORITY, requests);
}
@Override
public synchronized CompactionRequest requestCompaction(final HRegion r, final Store s,
final String why, CompactionRequest request) throws IOException {
return requestCompaction(r, s, why, Store.NO_PRIORITY, request);
}
@Override
public synchronized List<CompactionRequest> requestCompaction(final HRegion r, final String why,
int p, List<Pair<CompactionRequest, Store>> requests) throws IOException {
return requestCompactionInternal(r, why, p, requests, true);
}
private List<CompactionRequest> requestCompactionInternal(final HRegion r, final String why,
int p, List<Pair<CompactionRequest, Store>> requests, boolean selectNow) throws IOException {
// not a special compaction request, so make our own list
List<CompactionRequest> ret = null;
if (requests == null) {
ret = selectNow ? new ArrayList<CompactionRequest>(r.getStores().size()) : null;
for (Store s : r.getStores().values()) {
CompactionRequest cr = requestCompactionInternal(r, s, why, p, null, selectNow);
if (selectNow) ret.add(cr);
}
} else {
Preconditions.checkArgument(selectNow); // only system requests have selectNow == false
ret = new ArrayList<CompactionRequest>(requests.size());
for (Pair<CompactionRequest, Store> pair : requests) {
ret.add(requestCompaction(r, pair.getSecond(), why, p, pair.getFirst()));
}
}
return ret;
}
public CompactionRequest requestCompaction(final HRegion r, final Store s,
final String why, int priority, CompactionRequest request) throws IOException {
return requestCompactionInternal(r, s, why, priority, request, true);
}
public synchronized void requestSystemCompaction(
final HRegion r, final String why) throws IOException {
requestCompactionInternal(r, why, Store.NO_PRIORITY, null, false);
}
public void requestSystemCompaction(
final HRegion r, final Store s, final String why) throws IOException {
requestCompactionInternal(r, s, why, Store.NO_PRIORITY, null, false);
}
/**
* @param r HRegion store belongs to
* @param s Store to request compaction on
* @param why Why compaction requested -- used in debug messages
* @param priority override the default priority (NO_PRIORITY == decide)
* @param request custom compaction request. Can be <tt>null</tt> in which case a simple
* compaction will be used.
*/
private synchronized CompactionRequest requestCompactionInternal(final HRegion r, final Store s,
final String why, int priority, CompactionRequest request, boolean selectNow)
throws IOException {
if (this.server.isStopped()
|| (r.getTableDesc() != null && !r.getTableDesc().isCompactionEnabled())) {
return null;
}
CompactionContext compaction = null;
if (selectNow) {
compaction = selectCompaction(r, s, priority, request);
if (compaction == null) return null; // message logged inside
}
// We assume that most compactions are small. So, put system compactions into small
// pool; we will do selection there, and move to large pool if necessary.
long size = selectNow ? compaction.getRequest().getSize() : 0;
ThreadPoolExecutor pool = (!selectNow && s.throttleCompaction(size))
? largeCompactions : smallCompactions;
pool.execute(new CompactionRunner(s, r, compaction, pool));
if (LOG.isDebugEnabled()) {
String type = (pool == smallCompactions) ? "Small " : "Large ";
LOG.debug(type + "Compaction requested: " + (selectNow ? compaction.toString() : "system")
+ (why != null && !why.isEmpty() ? "; Because: " + why : "") + "; " + this);
}
return selectNow ? compaction.getRequest() : null;
}
private CompactionContext selectCompaction(final HRegion r, final Store s,
int priority, CompactionRequest request) throws IOException {
CompactionContext compaction = s.requestCompaction(priority, request);
if (compaction == null) {
if(LOG.isDebugEnabled()) {
LOG.debug("Not compacting " + r.getRegionNameAsString() +
" because compaction request was cancelled");
}
return null;
}
assert compaction.hasSelection();
if (priority != Store.NO_PRIORITY) {
compaction.getRequest().setPriority(priority);
}
return compaction;
}
/**
* Only interrupt once it's done with a run through the work loop.
*/
void interruptIfNecessary() {
splits.shutdown();
mergePool.shutdown();
largeCompactions.shutdown();
smallCompactions.shutdown();
}
private void waitFor(ThreadPoolExecutor t, String name) {
boolean done = false;
while (!done) {
try {
done = t.awaitTermination(60, TimeUnit.SECONDS);
LOG.info("Waiting for " + name + " to finish...");
if (!done) {
t.shutdownNow();
}
} catch (InterruptedException ie) {
LOG.warn("Interrupted waiting for " + name + " to finish...");
}
}
}
void join() {
waitFor(splits, "Split Thread");
waitFor(mergePool, "Merge Thread");
waitFor(largeCompactions, "Large Compaction Thread");
waitFor(smallCompactions, "Small Compaction Thread");
}
/**
* Returns the current size of the queue containing regions that are
* processed.
*
* @return The current size of the regions queue.
*/
public int getCompactionQueueSize() {
return largeCompactions.getQueue().size() + smallCompactions.getQueue().size();
}
public int getLargeCompactionQueueSize() {
return largeCompactions.getQueue().size();
}
public int getSmallCompactionQueueSize() {
return smallCompactions.getQueue().size();
}
private boolean shouldSplitRegion() {
return (regionSplitLimit > server.getNumberOfOnlineRegions());
}
/**
* @return the regionSplitLimit
*/
public int getRegionSplitLimit() {
return this.regionSplitLimit;
}
private class CompactionRunner implements Runnable, Comparable<CompactionRunner> {
private final Store store;
private final HRegion region;
private CompactionContext compaction;
private int queuedPriority;
private ThreadPoolExecutor parent;
public CompactionRunner(Store store, HRegion region,
CompactionContext compaction, ThreadPoolExecutor parent) {
super();
this.store = store;
this.region = region;
this.compaction = compaction;
this.queuedPriority = (this.compaction == null)
? store.getCompactPriority() : compaction.getRequest().getPriority();
this.parent = parent;
}
@Override
public String toString() {
return (this.compaction != null) ? ("Request = " + compaction.getRequest())
: ("Store = " + store.toString() + ", pri = " + queuedPriority);
}
@Override
public void run() {
Preconditions.checkNotNull(server);
if (server.isStopped()
|| (region.getTableDesc() != null && !region.getTableDesc().isCompactionEnabled())) {
return;
}
// Common case - system compaction without a file selection. Select now.
if (this.compaction == null) {
int oldPriority = this.queuedPriority;
this.queuedPriority = this.store.getCompactPriority();
if (this.queuedPriority > oldPriority) {
// Store priority decreased while we were in queue (due to some other compaction?),
// requeue with new priority to avoid blocking potential higher priorities.
this.parent.execute(this);
return;
}
try {
this.compaction = selectCompaction(this.region, this.store, queuedPriority, null);
} catch (IOException ex) {
LOG.error("Compaction selection failed " + this, ex);
server.checkFileSystem();
return;
}
if (this.compaction == null) return; // nothing to do
// Now see if we are in correct pool for the size; if not, go to the correct one.
// We might end up waiting for a while, so cancel the selection.
assert this.compaction.hasSelection();
ThreadPoolExecutor pool = store.throttleCompaction(
compaction.getRequest().getSize()) ? largeCompactions : smallCompactions;
if (this.parent != pool) {
this.store.cancelRequestedCompaction(this.compaction);
this.compaction = null;
this.parent = pool;
this.parent.execute(this);
return;
}
}
// Finally we can compact something.
assert this.compaction != null;
this.compaction.getRequest().beforeExecute();
try {
// Note: please don't put single-compaction logic here;
// put it into region/store/etc. This is CST logic.
long start = EnvironmentEdgeManager.currentTimeMillis();
boolean completed = region.compact(compaction, store);
long now = EnvironmentEdgeManager.currentTimeMillis();
LOG.info(((completed) ? "Completed" : "Aborted") + " compaction: " +
this + "; duration=" + StringUtils.formatTimeDiff(now, start));
if (completed) {
// degenerate case: blocked regions require recursive enqueues
if (store.getCompactPriority() <= 0) {
requestSystemCompaction(region, store, "Recursive enqueue");
} else {
// see if the compaction has caused us to exceed max region size
requestSplit(region);
}
}
} catch (IOException ex) {
IOException remoteEx = RemoteExceptionHandler.checkIOException(ex);
LOG.error("Compaction failed " + this, remoteEx);
if (remoteEx != ex) {
LOG.info("Compaction failed at original callstack: " + formatStackTrace(ex));
}
server.checkFileSystem();
} catch (Exception ex) {
LOG.error("Compaction failed " + this, ex);
server.checkFileSystem();
} finally {
LOG.debug("CompactSplitThread Status: " + CompactSplitThread.this);
}
this.compaction.getRequest().afterExecute();
}
private String formatStackTrace(Exception ex) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
ex.printStackTrace(pw);
pw.flush();
return sw.toString();
}
@Override
public int compareTo(CompactionRunner o) {
// Only compare the underlying request (if any), for queue sorting purposes.
int compareVal = queuedPriority - o.queuedPriority; // compare priority
if (compareVal != 0) return compareVal;
CompactionContext tc = this.compaction, oc = o.compaction;
// Sort pre-selected (user?) compactions before system ones with equal priority.
return (tc == null) ? ((oc == null) ? 0 : 1)
: ((oc == null) ? -1 : tc.getRequest().compareTo(oc.getRequest()));
}
}
/**
* Cleanup class to use when rejecting a compaction request from the queue.
*/
private static class Rejection implements RejectedExecutionHandler {
@Override
public void rejectedExecution(Runnable runnable, ThreadPoolExecutor pool) {
if (runnable instanceof CompactionRunner) {
CompactionRunner runner = (CompactionRunner)runnable;
LOG.debug("Compaction Rejected: " + runner);
runner.store.cancelRequestedCompaction(runner.compaction);
}
}
}
}