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* Licensed to the Apache Software Foundation (ASF) under one
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* 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.util.*;
import org.apache.cassandra.db.Memtable;
import org.apache.cassandra.db.lifecycle.SSTableSet;
import com.google.common.collect.Iterables;
import org.apache.cassandra.db.partitions.Partition;
import org.apache.cassandra.io.sstable.format.SSTableReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.db.ColumnFamilyStore;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.PartitionPosition;
import org.apache.cassandra.utils.AlwaysPresentFilter;
import org.apache.cassandra.utils.OverlapIterator;
import org.apache.cassandra.utils.concurrent.Refs;
import static org.apache.cassandra.db.lifecycle.SSTableIntervalTree.buildIntervals;
/**
* Manage compaction options.
*/
public class CompactionController implements AutoCloseable
{
private static final Logger logger = LoggerFactory.getLogger(CompactionController.class);
static final boolean NEVER_PURGE_TOMBSTONES = Boolean.getBoolean("cassandra.never_purge_tombstones");
public final ColumnFamilyStore cfs;
private final boolean compactingRepaired;
// note that overlapIterator and overlappingSSTables will be null if NEVER_PURGE_TOMBSTONES is set - this is a
// good thing so that noone starts using them and thinks that if overlappingSSTables is empty, there
// is no overlap.
private Refs<SSTableReader> overlappingSSTables;
private OverlapIterator<PartitionPosition, SSTableReader> overlapIterator;
private final Iterable<SSTableReader> compacting;
public final int gcBefore;
protected CompactionController(ColumnFamilyStore cfs, int maxValue)
{
this(cfs, null, maxValue);
}
public CompactionController(ColumnFamilyStore cfs, Set<SSTableReader> compacting, int gcBefore)
{
assert cfs != null;
this.cfs = cfs;
this.gcBefore = gcBefore;
this.compacting = compacting;
compactingRepaired = compacting != null && compacting.stream().allMatch(SSTableReader::isRepaired);
refreshOverlaps();
if (NEVER_PURGE_TOMBSTONES)
logger.warn("You are running with -Dcassandra.never_purge_tombstones=true, this is dangerous!");
}
public void maybeRefreshOverlaps()
{
if (NEVER_PURGE_TOMBSTONES)
{
logger.debug("not refreshing overlaps - running with -Dcassandra.never_purge_tombstones=true");
return;
}
for (SSTableReader reader : overlappingSSTables)
{
if (reader.isMarkedCompacted())
{
refreshOverlaps();
return;
}
}
}
private void refreshOverlaps()
{
if (NEVER_PURGE_TOMBSTONES)
return;
if (this.overlappingSSTables != null)
overlappingSSTables.release();
if (compacting == null)
overlappingSSTables = Refs.tryRef(Collections.<SSTableReader>emptyList());
else
overlappingSSTables = cfs.getAndReferenceOverlappingLiveSSTables(compacting);
this.overlapIterator = new OverlapIterator<>(buildIntervals(overlappingSSTables));
}
public Set<SSTableReader> getFullyExpiredSSTables()
{
return getFullyExpiredSSTables(cfs, compacting, overlappingSSTables, gcBefore);
}
/**
* Finds expired sstables
*
* works something like this;
* 1. find "global" minTimestamp of overlapping sstables, compacting sstables and memtables containing any non-expired data
* 2. build a list of fully expired candidates
* 3. check if the candidates to be dropped actually can be dropped (maxTimestamp < global minTimestamp)
* - if not droppable, remove from candidates
* 4. return candidates.
*
* @param cfStore
* @param compacting we take the drop-candidates from this set, it is usually the sstables included in the compaction
* @param overlapping the sstables that overlap the ones in compacting.
* @param gcBefore
* @return
*/
public static Set<SSTableReader> getFullyExpiredSSTables(ColumnFamilyStore cfStore, Iterable<SSTableReader> compacting, Iterable<SSTableReader> overlapping, int gcBefore)
{
logger.trace("Checking droppable sstables in {}", cfStore);
if (compacting == null || NEVER_PURGE_TOMBSTONES)
return Collections.<SSTableReader>emptySet();
if (cfStore.getCompactionStrategyManager().onlyPurgeRepairedTombstones() && !Iterables.all(compacting, SSTableReader::isRepaired))
return Collections.emptySet();
List<SSTableReader> candidates = new ArrayList<>();
long minTimestamp = Long.MAX_VALUE;
for (SSTableReader sstable : overlapping)
{
// Overlapping might include fully expired sstables. What we care about here is
// the min timestamp of the overlapping sstables that actually contain live data.
if (sstable.getSSTableMetadata().maxLocalDeletionTime >= gcBefore)
minTimestamp = Math.min(minTimestamp, sstable.getMinTimestamp());
}
for (SSTableReader candidate : compacting)
{
if (candidate.getSSTableMetadata().maxLocalDeletionTime < gcBefore)
candidates.add(candidate);
else
minTimestamp = Math.min(minTimestamp, candidate.getMinTimestamp());
}
for (Memtable memtable : cfStore.getTracker().getView().getAllMemtables())
minTimestamp = Math.min(minTimestamp, memtable.getMinTimestamp());
// At this point, minTimestamp denotes the lowest timestamp of any relevant
// SSTable or Memtable that contains a constructive value. candidates contains all the
// candidates with no constructive values. The ones out of these that have
// (getMaxTimestamp() < minTimestamp) serve no purpose anymore.
Iterator<SSTableReader> iterator = candidates.iterator();
while (iterator.hasNext())
{
SSTableReader candidate = iterator.next();
if (candidate.getMaxTimestamp() >= minTimestamp)
{
iterator.remove();
}
else
{
logger.trace("Dropping expired SSTable {} (maxLocalDeletionTime={}, gcBefore={})",
candidate, candidate.getSSTableMetadata().maxLocalDeletionTime, gcBefore);
}
}
return new HashSet<>(candidates);
}
public String getKeyspace()
{
return cfs.keyspace.getName();
}
public String getColumnFamily()
{
return cfs.name;
}
/**
* @return the largest timestamp before which it's okay to drop tombstones for the given partition;
* i.e., after the maxPurgeableTimestamp there may exist newer data that still needs to be suppressed
* in other sstables. This returns the minimum timestamp for any SSTable that contains this partition and is not
* participating in this compaction, or memtable that contains this partition,
* or LONG.MAX_VALUE if no SSTable or memtable exist.
*/
public long maxPurgeableTimestamp(DecoratedKey key)
{
if (!compactingRepaired() || NEVER_PURGE_TOMBSTONES)
return Long.MIN_VALUE;
long min = Long.MAX_VALUE;
overlapIterator.update(key);
for (SSTableReader sstable : overlapIterator.overlaps())
{
// if we don't have bloom filter(bf_fp_chance=1.0 or filter file is missing),
// we check index file instead.
if (sstable.getBloomFilter() instanceof AlwaysPresentFilter && sstable.getPosition(key, SSTableReader.Operator.EQ, false) != null)
min = Math.min(min, sstable.getMinTimestamp());
else if (sstable.getBloomFilter().isPresent(key))
min = Math.min(min, sstable.getMinTimestamp());
}
for (Memtable memtable : cfs.getTracker().getView().getAllMemtables())
{
Partition partition = memtable.getPartition(key);
if (partition != null)
min = Math.min(min, partition.stats().minTimestamp);
}
return min;
}
public void close()
{
if (overlappingSSTables != null)
overlappingSSTables.release();
}
public boolean compactingRepaired()
{
return !cfs.getCompactionStrategyManager().onlyPurgeRepairedTombstones() || compactingRepaired;
}
}