/* * 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.writers; import java.util.Arrays; import java.util.Set; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.apache.cassandra.db.ColumnFamilyStore; import org.apache.cassandra.db.Directories; import org.apache.cassandra.db.RowIndexEntry; import org.apache.cassandra.db.SerializationHeader; import org.apache.cassandra.db.rows.UnfilteredRowIterator; import org.apache.cassandra.db.lifecycle.LifecycleTransaction; import org.apache.cassandra.io.sstable.format.SSTableReader; import org.apache.cassandra.io.sstable.format.SSTableWriter; import org.apache.cassandra.io.sstable.metadata.MetadataCollector; /** * CompactionAwareWriter that splits input in differently sized sstables * * Biggest sstable will be total_compaction_size / 2, second biggest total_compaction_size / 4 etc until * the result would be sub 50MB, all those are put in the same */ public class SplittingSizeTieredCompactionWriter extends CompactionAwareWriter { private static final Logger logger = LoggerFactory.getLogger(SplittingSizeTieredCompactionWriter.class); public static final long DEFAULT_SMALLEST_SSTABLE_BYTES = 50_000_000; private final double[] ratios; private final long totalSize; private final Set<SSTableReader> allSSTables; private long currentBytesToWrite; private int currentRatioIndex = 0; private Directories.DataDirectory location; public SplittingSizeTieredCompactionWriter(ColumnFamilyStore cfs, Directories directories, LifecycleTransaction txn, Set<SSTableReader> nonExpiredSSTables) { this(cfs, directories, txn, nonExpiredSSTables, DEFAULT_SMALLEST_SSTABLE_BYTES); } public SplittingSizeTieredCompactionWriter(ColumnFamilyStore cfs, Directories directories, LifecycleTransaction txn, Set<SSTableReader> nonExpiredSSTables, long smallestSSTable) { super(cfs, directories, txn, nonExpiredSSTables, false, false); this.allSSTables = txn.originals(); totalSize = cfs.getExpectedCompactedFileSize(nonExpiredSSTables, txn.opType()); double[] potentialRatios = new double[20]; double currentRatio = 1; for (int i = 0; i < potentialRatios.length; i++) { currentRatio /= 2; potentialRatios[i] = currentRatio; } int noPointIndex = 0; // find how many sstables we should create - 50MB min sstable size for (double ratio : potentialRatios) { noPointIndex++; if (ratio * totalSize < smallestSSTable) { break; } } ratios = Arrays.copyOfRange(potentialRatios, 0, noPointIndex); currentBytesToWrite = Math.round(totalSize * ratios[currentRatioIndex]); } @Override public boolean realAppend(UnfilteredRowIterator partition) { RowIndexEntry rie = sstableWriter.append(partition); if (sstableWriter.currentWriter().getEstimatedOnDiskBytesWritten() > currentBytesToWrite && currentRatioIndex < ratios.length - 1) // if we underestimate how many keys we have, the last sstable might get more than we expect { currentRatioIndex++; currentBytesToWrite = Math.round(totalSize * ratios[currentRatioIndex]); switchCompactionLocation(location); logger.debug("Switching writer, currentBytesToWrite = {}", currentBytesToWrite); } return rie != null; } @Override public void switchCompactionLocation(Directories.DataDirectory location) { this.location = location; long currentPartitionsToWrite = Math.round(ratios[currentRatioIndex] * estimatedTotalKeys); @SuppressWarnings("resource") SSTableWriter writer = SSTableWriter.create(cfs.newSSTableDescriptor(getDirectories().getLocationForDisk(location)), currentPartitionsToWrite, minRepairedAt, pendingRepair, cfs.metadata, new MetadataCollector(allSSTables, cfs.metadata().comparator, 0), SerializationHeader.make(cfs.metadata(), nonExpiredSSTables), cfs.indexManager.listIndexes(), txn); logger.trace("Switching writer, currentPartitionsToWrite = {}", currentPartitionsToWrite); sstableWriter.switchWriter(writer); } }