/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
* by brackets "[]" replaced with your own identifying information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2008 Sun Microsystems, Inc.
*/
package org.opends.server.backends.jeb;
import com.sleepycat.je.Cursor;
import com.sleepycat.je.CursorConfig;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;
import java.util.Collection;
import org.opends.messages.Message;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import org.opends.server.api.DirectoryThread;
import org.opends.server.core.DirectoryServer;
import org.opends.server.types.DebugLogLevel;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.Entry;
import org.opends.server.types.ByteString;
import static org.opends.server.util.StaticUtils.*;
import static org.opends.server.loggers.debug.DebugLogger.*;
import static org.opends.server.loggers.ErrorLogger.logError;
import static org.opends.messages.ExtensionMessages.*;
/**
* This class defines a utility that will be used to pre-load the Directory
* Server entry cache. Pre-loader is multi-threaded and consist of the
* following threads:
*
* - The Arbiter thread which monitors overall pre-load progress and manages
* pre-load worker threads by adding or removing them as deemed necessary.
*
* - The Collector thread which collects all entries stored within the
* backend and places them to a blocking queue workers consume from.
*
* - Worker threads which are responsible for monitoring the collector feed
* and processing the actual entries for cache storage.
*
* This implementation is self-adjusting to any system workload and does not
* require any configuration parameters to optimize for initial system
* resources availability and/or any subsequent fluctuations.
*/
class EntryCachePreloader
{
/**
* The tracer object for the debug logger.
*/
private static final DebugTracer TRACER = getTracer();
/**
* BackendImpl object.
*/
private BackendImpl jeb;
/**
* Interrupt flag for the arbiter to terminate worker threads.
*/
private AtomicBoolean interruptFlag = new AtomicBoolean(false);
/**
* Processed entries counter.
*/
private AtomicLong processedEntries = new AtomicLong(0);
/**
* Progress report resolution.
*/
private static final long progressInterval = 5000;
/**
* Default resolution time.
*/
public static final long
PRELOAD_DEFAULT_SLEEP_TIME = 10000;
/**
* Effective synchronization time.
*/
private static long syncSleepTime;
/**
* Default queue capacity.
*/
public static final int
PRELOAD_DEFAULT_QUEUE_CAPACITY = 128;
/**
* Effective queue capacity.
*/
private static int queueCapacity;
/**
* Worker threads.
*/
private List<Thread> preloadThreads =
Collections.synchronizedList(
new LinkedList<Thread>());
/**
* Collector thread.
*/
private EntryCacheCollector collector =
new EntryCacheCollector();
/**
* This queue is for workers to take from.
*/
private LinkedBlockingQueue<PreloadEntry> entryQueue;
/**
* The number of bytes in a megabyte.
*/
private static final int bytesPerMegabyte = 1024*1024;
/**
* Constructs the Entry Cache Pre-loader for
* a given JEB implementation instance.
*
* @param jeb The JEB instance to pre-load.
*/
public EntryCachePreloader(BackendImpl jeb) {
// These should not be exposed as configuration
// parameters and are only useful for testing.
syncSleepTime = Long.getLong(
"org.opends.server.entrycache.preload.sleep",
PRELOAD_DEFAULT_SLEEP_TIME);
queueCapacity = Integer.getInteger(
"org.opends.server.entrycache.preload.queue",
PRELOAD_DEFAULT_QUEUE_CAPACITY);
entryQueue =
new LinkedBlockingQueue<PreloadEntry>(
queueCapacity);
this.jeb = jeb;
}
/**
* The Arbiter thread.
*/
protected void preload()
{
logError(NOTE_CACHE_PRELOAD_PROGRESS_START.get(jeb.getBackendID()));
// Start collector thread first.
collector.start();
// Kick off a single worker.
EntryCachePreloadWorker singleWorkerThread =
new EntryCachePreloadWorker();
singleWorkerThread.start();
preloadThreads.add(singleWorkerThread);
// Progress report timer task.
Timer timer = new Timer();
TimerTask progressTask = new TimerTask() {
// Persistent state restore progress report.
public void run() {
if (processedEntries.get() > 0) {
long freeMemory =
Runtime.getRuntime().freeMemory() / bytesPerMegabyte;
Message message = NOTE_CACHE_PRELOAD_PROGRESS_REPORT.get(
jeb.getBackendID(), processedEntries.get(), freeMemory);
logError(message);
}
}
};
timer.scheduleAtFixedRate(progressTask, progressInterval,
progressInterval);
// Cycle to monitor progress and adjust workers.
long processedEntriesCycle = 0;
long processedEntriesDelta = 0;
long processedEntriesDeltaLow = 0;
long processedEntriesDeltaHigh = 0;
long lastKnownProcessedEntries = 0;
try {
while (!entryQueue.isEmpty() || collector.isAlive()) {
Thread.sleep(syncSleepTime);
processedEntriesCycle = processedEntries.get();
processedEntriesDelta =
processedEntriesCycle - lastKnownProcessedEntries;
lastKnownProcessedEntries = processedEntriesCycle;
// Spawn another worker if scaling up.
if (processedEntriesDelta > processedEntriesDeltaHigh) {
processedEntriesDeltaLow = processedEntriesDeltaHigh;
processedEntriesDeltaHigh = processedEntriesDelta;
EntryCachePreloadWorker workerThread =
new EntryCachePreloadWorker();
workerThread.start();
preloadThreads.add(workerThread);
}
// Interrupt random worker if scaling down.
if (processedEntriesDelta < processedEntriesDeltaLow) {
processedEntriesDeltaHigh = processedEntriesDeltaLow;
processedEntriesDeltaLow = processedEntriesDelta;
// Leave at least one worker to progress.
if (preloadThreads.size() > 1) {
interruptFlag.set(true);
}
}
}
// Join the collector.
if (collector.isAlive()) {
collector.join();
}
// Join all spawned workers.
for (Thread workerThread : preloadThreads) {
if (workerThread.isAlive()) {
workerThread.join();
}
}
// Cancel progress report task and report done.
timer.cancel();
Message message = NOTE_CACHE_PRELOAD_PROGRESS_DONE.get(
jeb.getBackendID(), processedEntries.get());
logError(message);
} catch (InterruptedException ex) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, ex);
}
// Interrupt the collector.
collector.interrupt();
// Interrupt all preload threads.
for (Thread thread : preloadThreads) {
thread.interrupt();
}
logError(WARN_CACHE_PRELOAD_INTERRUPTED.get(
jeb.getBackendID()));
} finally {
// Kill the timer task.
timer.cancel();
}
}
/**
* The worker thread.
*/
private class EntryCachePreloadWorker extends DirectoryThread {
public EntryCachePreloadWorker() {
super("Entry Cache Preload Worker");
}
@Override
public void run() {
while (!entryQueue.isEmpty() || collector.isAlive()) {
// Check if interrupted.
if (Thread.interrupted()) {
return;
}
// Check for scaling down interruption.
if (interruptFlag.compareAndSet(true, false)) {
preloadThreads.remove(Thread.currentThread());
break;
}
// Dequeue the next entry.
try {
PreloadEntry preloadEntry = entryQueue.poll();
if (preloadEntry == null) {
continue;
}
long entryID =
JebFormat.entryIDFromDatabase(preloadEntry.entryIDBytes);
Entry entry =
ID2Entry.entryFromDatabase(ByteString.wrap(preloadEntry.entryBytes),
jeb.getRootContainer().getCompressedSchema());
try {
// Even if the entry does not end up in the cache its still
// treated as a processed entry anyways.
DirectoryServer.getEntryCache().putEntry(entry, jeb, entryID);
processedEntries.getAndIncrement();
} catch (Exception ex) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, ex);
}
Message message = ERR_CACHE_PRELOAD_ENTRY_FAILED.get(
entry.getDN().toNormalizedString(),
(ex.getCause() != null ? ex.getCause().getMessage() :
stackTraceToSingleLineString(ex)));
logError(message);
}
} catch (Exception ex) {
break;
}
}
}
}
/**
* The Collector thread.
*/
private class EntryCacheCollector extends DirectoryThread {
public EntryCacheCollector() {
super("Entry Cache Preload Collector");
}
@Override
public void run() {
Cursor cursor = null;
ID2Entry id2entry = null;
DatabaseEntry key = new DatabaseEntry();
DatabaseEntry data = new DatabaseEntry();
Collection<EntryContainer> entryContainers =
jeb.getRootContainer().getEntryContainers();
Iterator<EntryContainer> ecIterator =
entryContainers.iterator();
OperationStatus status = OperationStatus.SUCCESS;
try {
while (status == OperationStatus.SUCCESS) {
// Check if interrupted.
if (Thread.interrupted()) {
return;
}
try {
if (cursor == null) {
if (ecIterator.hasNext()) {
id2entry = ecIterator.next().getID2Entry();
} else {
break;
}
if (id2entry != null) {
cursor = id2entry.openCursor(null, new CursorConfig());
} else {
continue;
}
}
// BUG cursor might be null ? If not why testing below ?
status = cursor.getNext(key, data, LockMode.DEFAULT);
if (status != OperationStatus.SUCCESS) {
// Reset cursor and continue.
if (cursor != null) {
try {
cursor.close();
} catch (DatabaseException de) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, de);
}
}
status = OperationStatus.SUCCESS;
cursor = null;
continue;
}
} else {
entryQueue.put(new PreloadEntry(data.getData(),
key.getData()));
continue;
}
} catch (InterruptedException e) {
return;
} catch (Exception e) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
}
}
} finally {
// Always close cursor.
if (cursor != null) {
try {
cursor.close();
} catch (DatabaseException de) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, de);
}
}
}
}
}
}
/**
* This inner class represents pre-load entry object.
*/
private class PreloadEntry {
// Encoded Entry.
public byte[] entryBytes;
// Encoded EntryID.
public byte[] entryIDBytes;
/**
* Default constructor.
*/
public PreloadEntry(byte[] entryBytes, byte[] entryIDBytes) {
this.entryBytes = entryBytes;
this.entryIDBytes = entryIDBytes;
}
}
}