/**
*
* 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.compactions;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.regionserver.HStore;
import org.apache.hadoop.hbase.regionserver.RSRpcServices;
import org.apache.hadoop.hbase.regionserver.StoreConfigInformation;
import org.apache.hadoop.hbase.regionserver.StoreFile;
import org.apache.hadoop.hbase.regionserver.StoreUtils;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
/**
* The default algorithm for selecting files for compaction.
* Combines the compaction configuration and the provisional file selection that
* it's given to produce the list of suitable candidates for compaction.
*/
@InterfaceAudience.Private
public class RatioBasedCompactionPolicy extends SortedCompactionPolicy {
private static final Log LOG = LogFactory.getLog(RatioBasedCompactionPolicy.class);
public RatioBasedCompactionPolicy(Configuration conf,
StoreConfigInformation storeConfigInfo) {
super(conf, storeConfigInfo);
}
/*
* @param filesToCompact Files to compact. Can be null.
* @return True if we should run a major compaction.
*/
@Override
public boolean shouldPerformMajorCompaction(final Collection<StoreFile> filesToCompact)
throws IOException {
boolean result = false;
long mcTime = getNextMajorCompactTime(filesToCompact);
if (filesToCompact == null || filesToCompact.isEmpty() || mcTime == 0) {
return result;
}
// TODO: Use better method for determining stamp of last major (HBASE-2990)
long lowTimestamp = StoreUtils.getLowestTimestamp(filesToCompact);
long now = EnvironmentEdgeManager.currentTime();
if (lowTimestamp > 0L && lowTimestamp < (now - mcTime)) {
String regionInfo;
if (this.storeConfigInfo != null && this.storeConfigInfo instanceof HStore) {
regionInfo = ((HStore)this.storeConfigInfo).getRegionInfo().getRegionNameAsString();
} else {
regionInfo = this.toString();
}
// Major compaction time has elapsed.
long cfTTL = HConstants.FOREVER;
if (this.storeConfigInfo != null) {
cfTTL = this.storeConfigInfo.getStoreFileTtl();
}
if (filesToCompact.size() == 1) {
// Single file
StoreFile sf = filesToCompact.iterator().next();
Long minTimestamp = sf.getMinimumTimestamp();
long oldest = (minTimestamp == null) ? Long.MIN_VALUE : now - minTimestamp.longValue();
if (sf.isMajorCompaction() && (cfTTL == Long.MAX_VALUE || oldest < cfTTL)) {
float blockLocalityIndex =
sf.getHDFSBlockDistribution().getBlockLocalityIndex(
RSRpcServices.getHostname(comConf.conf, false));
if (blockLocalityIndex < comConf.getMinLocalityToForceCompact()) {
LOG.debug("Major compaction triggered on only store " + regionInfo
+ "; to make hdfs blocks local, current blockLocalityIndex is "
+ blockLocalityIndex + " (min " + comConf.getMinLocalityToForceCompact() + ")");
result = true;
} else {
LOG.debug("Skipping major compaction of " + regionInfo
+ " because one (major) compacted file only, oldestTime " + oldest
+ "ms is < TTL=" + cfTTL + " and blockLocalityIndex is " + blockLocalityIndex
+ " (min " + comConf.getMinLocalityToForceCompact() + ")");
}
} else if (cfTTL != HConstants.FOREVER && oldest > cfTTL) {
LOG.debug("Major compaction triggered on store " + regionInfo
+ ", because keyvalues outdated; time since last major compaction "
+ (now - lowTimestamp) + "ms");
result = true;
}
} else {
LOG.debug("Major compaction triggered on store " + regionInfo
+ "; time since last major compaction " + (now - lowTimestamp) + "ms");
}
result = true;
}
return result;
}
@Override
protected CompactionRequest createCompactionRequest(ArrayList<StoreFile>
candidateSelection, boolean tryingMajor, boolean mayUseOffPeak, boolean mayBeStuck)
throws IOException {
if (!tryingMajor) {
candidateSelection = filterBulk(candidateSelection);
candidateSelection = applyCompactionPolicy(candidateSelection, mayUseOffPeak, mayBeStuck);
candidateSelection = checkMinFilesCriteria(candidateSelection,
comConf.getMinFilesToCompact());
}
return new CompactionRequest(candidateSelection);
}
/**
* -- Default minor compaction selection algorithm:
* choose CompactSelection from candidates --
* First exclude bulk-load files if indicated in configuration.
* Start at the oldest file and stop when you find the first file that
* meets compaction criteria:
* (1) a recently-flushed, small file (i.e. <= minCompactSize)
* OR
* (2) within the compactRatio of sum(newer_files)
* Given normal skew, any newer files will also meet this criteria
* <p/>
* Additional Note:
* If fileSizes.size() >> maxFilesToCompact, we will recurse on
* compact(). Consider the oldest files first to avoid a
* situation where we always compact [end-threshold,end). Then, the
* last file becomes an aggregate of the previous compactions.
*
* normal skew:
*
* older ----> newer (increasing seqID)
* _
* | | _
* | | | | _
* --|-|- |-|- |-|---_-------_------- minCompactSize
* | | | | | | | | _ | |
* | | | | | | | | | | | |
* | | | | | | | | | | | |
* @param candidates pre-filtrate
* @return filtered subset
*/
protected ArrayList<StoreFile> applyCompactionPolicy(ArrayList<StoreFile> candidates,
boolean mayUseOffPeak, boolean mayBeStuck) throws IOException {
if (candidates.isEmpty()) {
return candidates;
}
// we're doing a minor compaction, let's see what files are applicable
int start = 0;
double ratio = comConf.getCompactionRatio();
if (mayUseOffPeak) {
ratio = comConf.getCompactionRatioOffPeak();
LOG.info("Running an off-peak compaction, selection ratio = " + ratio);
}
// get store file sizes for incremental compacting selection.
final int countOfFiles = candidates.size();
long[] fileSizes = new long[countOfFiles];
long[] sumSize = new long[countOfFiles];
for (int i = countOfFiles - 1; i >= 0; --i) {
StoreFile file = candidates.get(i);
fileSizes[i] = file.getReader().length();
// calculate the sum of fileSizes[i,i+maxFilesToCompact-1) for algo
int tooFar = i + comConf.getMaxFilesToCompact() - 1;
sumSize[i] = fileSizes[i]
+ ((i + 1 < countOfFiles) ? sumSize[i + 1] : 0)
- ((tooFar < countOfFiles) ? fileSizes[tooFar] : 0);
}
while (countOfFiles - start >= comConf.getMinFilesToCompact() &&
fileSizes[start] > Math.max(comConf.getMinCompactSize(),
(long) (sumSize[start + 1] * ratio))) {
++start;
}
if (start < countOfFiles) {
LOG.info("Default compaction algorithm has selected " + (countOfFiles - start)
+ " files from " + countOfFiles + " candidates");
} else if (mayBeStuck) {
// We may be stuck. Compact the latest files if we can.
int filesToLeave = candidates.size() - comConf.getMinFilesToCompact();
if (filesToLeave >= 0) {
start = filesToLeave;
}
}
candidates.subList(0, start).clear();
return candidates;
}
/**
* A heuristic method to decide whether to schedule a compaction request
* @param storeFiles files in the store.
* @param filesCompacting files being scheduled to compact.
* @return true to schedule a request.
*/
public boolean needsCompaction(final Collection<StoreFile> storeFiles,
final List<StoreFile> filesCompacting) {
int numCandidates = storeFiles.size() - filesCompacting.size();
return numCandidates >= comConf.getMinFilesToCompact();
}
/**
* Overwrite min threshold for compaction
*/
public void setMinThreshold(int minThreshold) {
comConf.setMinFilesToCompact(minThreshold);
}
}