/**
* 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.cassandra.db.compaction;
import java.io.IOException;
import java.util.*;
import java.util.Map.Entry;
import com.google.common.base.Predicates;
import com.google.common.collect.Iterators;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.commons.lang.StringUtils;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.ColumnFamilyStore;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.compaction.CompactionManager.CompactionExecutorStatsCollector;
import org.apache.cassandra.io.sstable.SSTable;
import org.apache.cassandra.io.sstable.SSTableReader;
import org.apache.cassandra.io.sstable.SSTableWriter;
import org.apache.cassandra.utils.CloseableIterator;
import org.apache.cassandra.utils.FBUtilities;
public class CompactionTask extends AbstractCompactionTask
{
protected static final Logger logger = LoggerFactory.getLogger(CompactionTask.class);
protected String compactionFileLocation;
protected final int gcBefore;
protected boolean isUserDefined;
protected static long totalBytesCompacted = 0;
public CompactionTask(ColumnFamilyStore cfs, Collection<SSTableReader> sstables, final int gcBefore)
{
super(cfs, sstables);
compactionFileLocation = null;
this.gcBefore = gcBefore;
this.isUserDefined = false;
}
public static synchronized long addToTotalBytesCompacted(long bytesCompacted)
{
return totalBytesCompacted += bytesCompacted;
}
/**
* For internal use and testing only. The rest of the system should go through the submit* methods,
* which are properly serialized.
* Caller is in charge of marking/unmarking the sstables as compacting.
*/
public int execute(CompactionExecutorStatsCollector collector) throws IOException
{
// The collection of sstables passed may be empty (but not null); even if
// it is not empty, it may compact down to nothing if all rows are deleted.
assert sstables != null;
Set<SSTableReader> toCompact = new HashSet<SSTableReader>(sstables);
if (!isCompactionInteresting(toCompact))
return 0;
if (compactionFileLocation == null)
compactionFileLocation = cfs.table.getDataFileLocation(cfs.getExpectedCompactedFileSize(toCompact));
if (partialCompactionsAcceptable())
{
// If the compaction file path is null that means we have no space left for this compaction.
// Try again w/o the largest one.
if (compactionFileLocation == null)
{
while (compactionFileLocation == null && toCompact.size() > 1)
{
logger.warn("insufficient space to compact all requested files " + StringUtils.join(toCompact, ", "));
// Note that we have removed files that are still marked as compacting. This suboptimal but ok since the caller will unmark all
// the sstables at the end.
toCompact.remove(cfs.getMaxSizeFile(toCompact));
compactionFileLocation = cfs.table.getDataFileLocation(cfs.getExpectedCompactedFileSize(toCompact));
}
}
if (compactionFileLocation == null)
{
logger.warn("insufficient space to compact even the two smallest files, aborting");
return 0;
}
}
if (DatabaseDescriptor.isSnapshotBeforeCompaction())
cfs.table.snapshot(System.currentTimeMillis() + "-" + "compact-" + cfs.columnFamily);
// sanity check: all sstables must belong to the same cfs
for (SSTableReader sstable : toCompact)
assert sstable.descriptor.cfname.equals(cfs.columnFamily);
CompactionController controller = new CompactionController(cfs, toCompact, gcBefore, isUserDefined);
// new sstables from flush can be added during a compaction, but only the compaction can remove them,
// so in our single-threaded compaction world this is a valid way of determining if we're compacting
// all the sstables (that existed when we started)
logger.info("Compacting {}", toCompact);
long startTime = System.currentTimeMillis();
long totalkeysWritten = 0;
long estimatedTotalKeys = Math.max(DatabaseDescriptor.getIndexInterval(), SSTableReader.getApproximateKeyCount(toCompact));
long estimatedSSTables = Math.max(1, SSTable.getTotalBytes(toCompact) / cfs.getCompactionStrategy().getMaxSSTableSize());
long keysPerSSTable = (long) Math.ceil((double) estimatedTotalKeys / estimatedSSTables);
if (logger.isDebugEnabled())
logger.debug("Expected bloom filter size : " + keysPerSSTable);
AbstractCompactionIterable ci = DatabaseDescriptor.isMultithreadedCompaction()
? new ParallelCompactionIterable(OperationType.COMPACTION, toCompact, controller)
: new CompactionIterable(OperationType.COMPACTION, toCompact, controller);
CloseableIterator<AbstractCompactedRow> iter = ci.iterator();
Iterator<AbstractCompactedRow> nni = Iterators.filter(iter, Predicates.notNull());
Map<DecoratedKey, Long> cachedKeys = new HashMap<DecoratedKey, Long>();
// we can't preheat until the tracker has been set. This doesn't happen until we tell the cfs to
// replace the old entries. Track entries to preheat here until then.
Map<SSTableReader, Map<DecoratedKey, Long>> cachedKeyMap = new HashMap<SSTableReader, Map<DecoratedKey, Long>>();
Collection<SSTableReader> sstables = new ArrayList<SSTableReader>();
Collection<SSTableWriter> writers = new ArrayList<SSTableWriter>();
if (collector != null)
collector.beginCompaction(ci);
try
{
if (!nni.hasNext())
{
// don't mark compacted in the finally block, since if there _is_ nondeleted data,
// we need to sync it (via closeAndOpen) first, so there is no period during which
// a crash could cause data loss.
cfs.markCompacted(toCompact);
return 0;
}
SSTableWriter writer = cfs.createCompactionWriter(keysPerSSTable, compactionFileLocation, toCompact);
writers.add(writer);
while (nni.hasNext())
{
AbstractCompactedRow row = nni.next();
if (row.isEmpty())
continue;
long position = writer.append(row);
totalkeysWritten++;
if (DatabaseDescriptor.getPreheatKeyCache())
{
for (SSTableReader sstable : toCompact)
{
if (sstable.getCachedPosition(row.key, false) != null)
{
cachedKeys.put(row.key, position);
break;
}
}
}
if (!nni.hasNext() || newSSTableSegmentThresholdReached(writer, position))
{
SSTableReader toIndex = writer.closeAndOpenReader(getMaxDataAge(toCompact));
cachedKeyMap.put(toIndex, cachedKeys);
sstables.add(toIndex);
writer = cfs.createCompactionWriter(keysPerSSTable, compactionFileLocation, toCompact);
writers.add(writer);
cachedKeys = new HashMap<DecoratedKey, Long>();
}
}
}
catch (Exception e)
{
for (SSTableWriter writer : writers)
writer.abort();
throw FBUtilities.unchecked(e);
}
finally
{
iter.close();
if (collector != null)
collector.finishCompaction(ci);
}
cfs.replaceCompactedSSTables(toCompact, sstables);
// TODO: this doesn't belong here, it should be part of the reader to load when the tracker is wired up
for (Entry<SSTableReader, Map<DecoratedKey, Long>> ssTableReaderMapEntry : cachedKeyMap.entrySet())
{
SSTableReader key = ssTableReaderMapEntry.getKey();
for (Entry<DecoratedKey, Long> entry : ssTableReaderMapEntry.getValue().entrySet())
key.cacheKey(entry.getKey(), entry.getValue());
}
long dTime = System.currentTimeMillis() - startTime;
long startsize = SSTable.getTotalBytes(toCompact);
long endsize = SSTable.getTotalBytes(sstables);
double ratio = (double)endsize / (double)startsize;
StringBuilder builder = new StringBuilder();
builder.append("[");
for (SSTableReader reader : sstables)
builder.append(reader.getFilename()).append(",");
builder.append("]");
double mbps = dTime > 0 ? (double)endsize/(1024*1024)/((double)dTime/1000) : 0;
logger.info(String.format("Compacted to %s. %,d to %,d (~%d%% of original) bytes for %,d keys at %fMB/s. Time: %,dms.",
builder.toString(), startsize, endsize, (int) (ratio * 100), totalkeysWritten, mbps, dTime));
logger.debug(String.format("CF Total Bytes Compacted: %,d", CompactionTask.addToTotalBytesCompacted(endsize)));
return toCompact.size();
}
protected boolean partialCompactionsAcceptable()
{
return !isUserDefined;
}
//extensibility point for other strategies that may want to limit the upper bounds of the sstable segment size
protected boolean newSSTableSegmentThresholdReached(SSTableWriter writer, long position)
{
return false;
}
/**
* @return true if the proposed compaction is worth proceeding with. We allow leveled compaction to
* override this to allow "promoting" sstables from one level to another w/o rewriting them, if there is no overlapping.
*/
protected boolean isCompactionInteresting(Set<SSTableReader> toCompact)
{
if (isUserDefined || toCompact.size() >= 2)
return true;
logger.info(String.format("Nothing to compact in %s. Use forceUserDefinedCompaction if you wish to force compaction of single sstables (e.g. for tombstone collection)",
cfs.getColumnFamilyName()));
return false;
}
public static long getMaxDataAge(Collection<SSTableReader> sstables)
{
long max = 0;
for (SSTableReader sstable : sstables)
{
if (sstable.maxDataAge > max)
max = sstable.maxDataAge;
}
return max;
}
public CompactionTask compactionFileLocation(String compactionFileLocation)
{
this.compactionFileLocation = compactionFileLocation;
return this;
}
public CompactionTask isUserDefined(boolean isUserDefined)
{
this.isUserDefined = isUserDefined;
return this;
}
}