| /* |
| * 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.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.TreeSet; |
| import java.util.concurrent.TimeUnit; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.collect.*; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.cassandra.db.ColumnFamilyStore; |
| import org.apache.cassandra.db.lifecycle.SSTableSet; |
| import org.apache.cassandra.db.lifecycle.LifecycleTransaction; |
| import org.apache.cassandra.exceptions.ConfigurationException; |
| import org.apache.cassandra.io.sstable.format.SSTableReader; |
| import org.apache.cassandra.schema.CompactionParams; |
| import org.apache.cassandra.utils.Pair; |
| |
| import static com.google.common.collect.Iterables.filter; |
| |
| public class TimeWindowCompactionStrategy extends AbstractCompactionStrategy |
| { |
| private static final Logger logger = LoggerFactory.getLogger(TimeWindowCompactionStrategy.class); |
| |
| private final TimeWindowCompactionStrategyOptions options; |
| protected volatile int estimatedRemainingTasks; |
| private final Set<SSTableReader> sstables = new HashSet<>(); |
| private long lastExpiredCheck; |
| private long highestWindowSeen; |
| |
| public TimeWindowCompactionStrategy(ColumnFamilyStore cfs, Map<String, String> options) |
| { |
| super(cfs, options); |
| this.estimatedRemainingTasks = 0; |
| this.options = new TimeWindowCompactionStrategyOptions(options); |
| if (!options.containsKey(AbstractCompactionStrategy.TOMBSTONE_COMPACTION_INTERVAL_OPTION) && !options.containsKey(AbstractCompactionStrategy.TOMBSTONE_THRESHOLD_OPTION)) |
| { |
| disableTombstoneCompactions = true; |
| logger.debug("Disabling tombstone compactions for TWCS"); |
| } |
| else |
| logger.debug("Enabling tombstone compactions for TWCS"); |
| |
| } |
| |
| @Override |
| @SuppressWarnings("resource") // transaction is closed by AbstractCompactionTask::execute |
| public AbstractCompactionTask getNextBackgroundTask(int gcBefore) |
| { |
| while (true) |
| { |
| List<SSTableReader> latestBucket = getNextBackgroundSSTables(gcBefore); |
| |
| if (latestBucket.isEmpty()) |
| return null; |
| |
| LifecycleTransaction modifier = cfs.getTracker().tryModify(latestBucket, OperationType.COMPACTION); |
| if (modifier != null) |
| return new CompactionTask(cfs, modifier, gcBefore); |
| } |
| } |
| |
| /** |
| * |
| * @param gcBefore |
| * @return |
| */ |
| private synchronized List<SSTableReader> getNextBackgroundSSTables(final int gcBefore) |
| { |
| if (Iterables.isEmpty(cfs.getSSTables(SSTableSet.LIVE))) |
| return Collections.emptyList(); |
| |
| Set<SSTableReader> uncompacting = ImmutableSet.copyOf(filter(cfs.getUncompactingSSTables(), sstables::contains)); |
| |
| // Find fully expired SSTables. Those will be included no matter what. |
| Set<SSTableReader> expired = Collections.emptySet(); |
| |
| if (System.currentTimeMillis() - lastExpiredCheck > options.expiredSSTableCheckFrequency) |
| { |
| logger.debug("TWCS expired check sufficiently far in the past, checking for fully expired SSTables"); |
| expired = CompactionController.getFullyExpiredSSTables(cfs, uncompacting, cfs.getOverlappingLiveSSTables(uncompacting), gcBefore); |
| lastExpiredCheck = System.currentTimeMillis(); |
| } |
| else |
| { |
| logger.debug("TWCS skipping check for fully expired SSTables"); |
| } |
| |
| Set<SSTableReader> candidates = Sets.newHashSet(filterSuspectSSTables(uncompacting)); |
| |
| List<SSTableReader> compactionCandidates = new ArrayList<>(getNextNonExpiredSSTables(Sets.difference(candidates, expired), gcBefore)); |
| if (!expired.isEmpty()) |
| { |
| logger.debug("Including expired sstables: {}", expired); |
| compactionCandidates.addAll(expired); |
| } |
| |
| return compactionCandidates; |
| } |
| |
| private List<SSTableReader> getNextNonExpiredSSTables(Iterable<SSTableReader> nonExpiringSSTables, final int gcBefore) |
| { |
| List<SSTableReader> mostInteresting = getCompactionCandidates(nonExpiringSSTables); |
| |
| if (mostInteresting != null) |
| { |
| return mostInteresting; |
| } |
| |
| // if there is no sstable to compact in standard way, try compacting single sstable whose droppable tombstone |
| // ratio is greater than threshold. |
| List<SSTableReader> sstablesWithTombstones = new ArrayList<>(); |
| for (SSTableReader sstable : nonExpiringSSTables) |
| { |
| if (worthDroppingTombstones(sstable, gcBefore)) |
| sstablesWithTombstones.add(sstable); |
| } |
| if (sstablesWithTombstones.isEmpty()) |
| return Collections.emptyList(); |
| |
| return Collections.singletonList(Collections.min(sstablesWithTombstones, new SSTableReader.SizeComparator())); |
| } |
| |
| private List<SSTableReader> getCompactionCandidates(Iterable<SSTableReader> candidateSSTables) |
| { |
| Pair<HashMultimap<Long, SSTableReader>, Long> buckets = getBuckets(candidateSSTables, options.sstableWindowUnit, options.sstableWindowSize, options.timestampResolution); |
| // Update the highest window seen, if necessary |
| if(buckets.right > this.highestWindowSeen) |
| this.highestWindowSeen = buckets.right; |
| |
| updateEstimatedCompactionsByTasks(buckets.left); |
| List<SSTableReader> mostInteresting = newestBucket(buckets.left, |
| cfs.getMinimumCompactionThreshold(), |
| cfs.getMaximumCompactionThreshold(), |
| options.sstableWindowUnit, |
| options.sstableWindowSize, |
| options.stcsOptions, |
| this.highestWindowSeen); |
| if (!mostInteresting.isEmpty()) |
| return mostInteresting; |
| return null; |
| } |
| |
| @Override |
| public synchronized void addSSTable(SSTableReader sstable) |
| { |
| sstables.add(sstable); |
| } |
| |
| @Override |
| public synchronized void removeSSTable(SSTableReader sstable) |
| { |
| sstables.remove(sstable); |
| } |
| |
| /** |
| * Find the lowest and highest timestamps in a given timestamp/unit pair |
| * Returns milliseconds, caller should adjust accordingly |
| */ |
| public static Pair<Long,Long> getWindowBoundsInMillis(TimeUnit windowTimeUnit, int windowTimeSize, long timestampInMillis) |
| { |
| long lowerTimestamp; |
| long upperTimestamp; |
| long timestampInSeconds = TimeUnit.SECONDS.convert(timestampInMillis, TimeUnit.MILLISECONDS); |
| |
| switch(windowTimeUnit) |
| { |
| case MINUTES: |
| lowerTimestamp = timestampInSeconds - ((timestampInSeconds) % (60 * windowTimeSize)); |
| upperTimestamp = (lowerTimestamp + (60L * (windowTimeSize - 1L))) + 59L; |
| break; |
| case HOURS: |
| lowerTimestamp = timestampInSeconds - ((timestampInSeconds) % (3600 * windowTimeSize)); |
| upperTimestamp = (lowerTimestamp + (3600L * (windowTimeSize - 1L))) + 3599L; |
| break; |
| case DAYS: |
| default: |
| lowerTimestamp = timestampInSeconds - ((timestampInSeconds) % (86400 * windowTimeSize)); |
| upperTimestamp = (lowerTimestamp + (86400L * (windowTimeSize - 1L))) + 86399L; |
| break; |
| } |
| |
| return Pair.create(TimeUnit.MILLISECONDS.convert(lowerTimestamp, TimeUnit.SECONDS), |
| TimeUnit.MILLISECONDS.convert(upperTimestamp, TimeUnit.SECONDS)); |
| |
| } |
| |
| /** |
| * Group files with similar max timestamp into buckets. |
| * |
| * @param files pairs consisting of a file and its min timestamp |
| * @param sstableWindowUnit |
| * @param sstableWindowSize |
| * @param timestampResolution |
| * @return A pair, where the left element is the bucket representation (map of timestamp to sstablereader), and the right is the highest timestamp seen |
| */ |
| @VisibleForTesting |
| static Pair<HashMultimap<Long, SSTableReader>, Long> getBuckets(Iterable<SSTableReader> files, TimeUnit sstableWindowUnit, int sstableWindowSize, TimeUnit timestampResolution) |
| { |
| HashMultimap<Long, SSTableReader> buckets = HashMultimap.create(); |
| |
| long maxTimestamp = 0; |
| // Create hash map to represent buckets |
| // For each sstable, add sstable to the time bucket |
| // Where the bucket is the file's max timestamp rounded to the nearest window bucket |
| for (SSTableReader f : files) |
| { |
| assert TimeWindowCompactionStrategyOptions.validTimestampTimeUnits.contains(timestampResolution); |
| long tStamp = TimeUnit.MILLISECONDS.convert(f.getMaxTimestamp(), timestampResolution); |
| Pair<Long,Long> bounds = getWindowBoundsInMillis(sstableWindowUnit, sstableWindowSize, tStamp); |
| buckets.put(bounds.left, f); |
| if (bounds.left > maxTimestamp) |
| maxTimestamp = bounds.left; |
| } |
| |
| logger.trace("buckets {}, max timestamp", buckets, maxTimestamp); |
| return Pair.create(buckets, maxTimestamp); |
| } |
| |
| private void updateEstimatedCompactionsByTasks(HashMultimap<Long, SSTableReader> tasks) |
| { |
| int n = 0; |
| long now = this.highestWindowSeen; |
| |
| for(Long key : tasks.keySet()) |
| { |
| // For current window, make sure it's compactable |
| if (key.compareTo(now) >= 0 && tasks.get(key).size() >= cfs.getMinimumCompactionThreshold()) |
| n++; |
| else if (key.compareTo(now) < 0 && tasks.get(key).size() >= 2) |
| n++; |
| } |
| this.estimatedRemainingTasks = n; |
| } |
| |
| |
| /** |
| * @param buckets list of buckets, sorted from newest to oldest, from which to return the newest bucket within thresholds. |
| * @param minThreshold minimum number of sstables in a bucket to qualify. |
| * @param maxThreshold maximum number of sstables to compact at once (the returned bucket will be trimmed down to this). |
| * @return a bucket (list) of sstables to compact. |
| */ |
| @VisibleForTesting |
| static List<SSTableReader> newestBucket(HashMultimap<Long, SSTableReader> buckets, int minThreshold, int maxThreshold, TimeUnit sstableWindowUnit, int sstableWindowSize, SizeTieredCompactionStrategyOptions stcsOptions, long now) |
| { |
| // If the current bucket has at least minThreshold SSTables, choose that one. |
| // For any other bucket, at least 2 SSTables is enough. |
| // In any case, limit to maxThreshold SSTables. |
| |
| TreeSet<Long> allKeys = new TreeSet<>(buckets.keySet()); |
| |
| Iterator<Long> it = allKeys.descendingIterator(); |
| while(it.hasNext()) |
| { |
| Long key = it.next(); |
| Set<SSTableReader> bucket = buckets.get(key); |
| logger.trace("Key {}, now {}", key, now); |
| if (bucket.size() >= minThreshold && key >= now) |
| { |
| // If we're in the newest bucket, we'll use STCS to prioritize sstables |
| List<Pair<SSTableReader,Long>> pairs = SizeTieredCompactionStrategy.createSSTableAndLengthPairs(bucket); |
| List<List<SSTableReader>> stcsBuckets = SizeTieredCompactionStrategy.getBuckets(pairs, stcsOptions.bucketHigh, stcsOptions.bucketLow, stcsOptions.minSSTableSize); |
| logger.debug("Using STCS compaction for first window of bucket: data files {} , options {}", pairs, stcsOptions); |
| List<SSTableReader> stcsInterestingBucket = SizeTieredCompactionStrategy.mostInterestingBucket(stcsBuckets, minThreshold, maxThreshold); |
| |
| // If the tables in the current bucket aren't eligible in the STCS strategy, we'll skip it and look for other buckets |
| if (!stcsInterestingBucket.isEmpty()) |
| return stcsInterestingBucket; |
| } |
| else if (bucket.size() >= 2 && key < now) |
| { |
| logger.debug("bucket size {} >= 2 and not in current bucket, compacting what's here: {}", bucket.size(), bucket); |
| return trimToThreshold(bucket, maxThreshold); |
| } |
| else |
| { |
| logger.trace("No compaction necessary for bucket size {} , key {}, now {}", bucket.size(), key, now); |
| } |
| } |
| return Collections.<SSTableReader>emptyList(); |
| } |
| |
| /** |
| * @param bucket set of sstables |
| * @param maxThreshold maximum number of sstables in a single compaction task. |
| * @return A bucket trimmed to the maxThreshold newest sstables. |
| */ |
| @VisibleForTesting |
| static List<SSTableReader> trimToThreshold(Set<SSTableReader> bucket, int maxThreshold) |
| { |
| List<SSTableReader> ssTableReaders = new ArrayList<>(bucket); |
| |
| // Trim the largest sstables off the end to meet the maxThreshold |
| Collections.sort(ssTableReaders, new SSTableReader.SizeComparator()); |
| |
| return ImmutableList.copyOf(Iterables.limit(ssTableReaders, maxThreshold)); |
| } |
| |
| @Override |
| @SuppressWarnings("resource") // transaction is closed by AbstractCompactionTask::execute |
| public synchronized Collection<AbstractCompactionTask> getMaximalTask(int gcBefore, boolean splitOutput) |
| { |
| Iterable<SSTableReader> filteredSSTables = filterSuspectSSTables(sstables); |
| if (Iterables.isEmpty(filteredSSTables)) |
| return null; |
| LifecycleTransaction txn = cfs.getTracker().tryModify(filteredSSTables, OperationType.COMPACTION); |
| if (txn == null) |
| return null; |
| return Collections.singleton(new CompactionTask(cfs, txn, gcBefore)); |
| } |
| |
| @Override |
| @SuppressWarnings("resource") // transaction is closed by AbstractCompactionTask::execute |
| public synchronized AbstractCompactionTask getUserDefinedTask(Collection<SSTableReader> sstables, int gcBefore) |
| { |
| assert !sstables.isEmpty(); // checked for by CM.submitUserDefined |
| |
| LifecycleTransaction modifier = cfs.getTracker().tryModify(sstables, OperationType.COMPACTION); |
| if (modifier == null) |
| { |
| logger.debug("Unable to mark {} for compaction; probably a background compaction got to it first. You can disable background compactions temporarily if this is a problem", sstables); |
| return null; |
| } |
| |
| return new CompactionTask(cfs, modifier, gcBefore).setUserDefined(true); |
| } |
| |
| public int getEstimatedRemainingTasks() |
| { |
| return this.estimatedRemainingTasks; |
| } |
| |
| public long getMaxSSTableBytes() |
| { |
| return Long.MAX_VALUE; |
| } |
| |
| |
| public static Map<String, String> validateOptions(Map<String, String> options) throws ConfigurationException |
| { |
| Map<String, String> uncheckedOptions = AbstractCompactionStrategy.validateOptions(options); |
| uncheckedOptions = TimeWindowCompactionStrategyOptions.validateOptions(options, uncheckedOptions); |
| |
| uncheckedOptions.remove(CompactionParams.Option.MIN_THRESHOLD.toString()); |
| uncheckedOptions.remove(CompactionParams.Option.MAX_THRESHOLD.toString()); |
| |
| return uncheckedOptions; |
| } |
| |
| public String toString() |
| { |
| return String.format("TimeWindowCompactionStrategy[%s/%s]", |
| cfs.getMinimumCompactionThreshold(), |
| cfs.getMaximumCompactionThreshold()); |
| } |
| } |