Java tutorial
/** * * 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; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.TreeMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.HConstants; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.KeyValue.KVComparator; import org.apache.hadoop.hbase.regionserver.compactions.StripeCompactionPolicy; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.hbase.util.ConcatenatedLists; import com.google.common.collect.ImmutableCollection; import com.google.common.collect.ImmutableList; import com.google.common.collect.Lists; /** * Stripe implementation of StoreFileManager. * Not thread safe - relies on external locking (in HStore). Collections that this class * returns are immutable or unique to the call, so they should be safe. * Stripe store splits the key space of the region into non-overlapping stripes, as well as * some recent files that have all the keys (level 0). Each stripe contains a set of files. * When L0 is compacted, it's split into the files corresponding to existing stripe boundaries, * that can thus be added to stripes. * When scan or get happens, it only has to read the files from the corresponding stripes. * See StripeCompationPolicy on how the stripes are determined; this class doesn't care. * * This class should work together with StripeCompactionPolicy and StripeCompactor. * With regard to how they work, we make at least the following (reasonable) assumptions: * - Compaction produces one file per new stripe (if any); that is easy to change. * - Compaction has one contiguous set of stripes both in and out, except if L0 is involved. */ @InterfaceAudience.Private public class StripeStoreFileManager implements StoreFileManager, StripeCompactionPolicy.StripeInformationProvider { static final Log LOG = LogFactory.getLog(StripeStoreFileManager.class); /** * The file metadata fields that contain the stripe information. */ public static final byte[] STRIPE_START_KEY = Bytes.toBytes("STRIPE_START_KEY"); public static final byte[] STRIPE_END_KEY = Bytes.toBytes("STRIPE_END_KEY"); private final static Bytes.RowEndKeyComparator MAP_COMPARATOR = new Bytes.RowEndKeyComparator(); /** * The key value used for range boundary, indicating that the boundary is open (i.e. +-inf). */ public final static byte[] OPEN_KEY = HConstants.EMPTY_BYTE_ARRAY; final static byte[] INVALID_KEY = null; /** * The state class. Used solely to replace results atomically during * compactions and avoid complicated error handling. */ private static class State { /** * The end rows of each stripe. The last stripe end is always open-ended, so it's not stored * here. It is invariant that the start row of the stripe is the end row of the previous one * (and is an open boundary for the first one). */ public byte[][] stripeEndRows = new byte[0][]; /** * Files by stripe. Each element of the list corresponds to stripeEndRow element with the * same index, except the last one. Inside each list, the files are in reverse order by * seqNum. Note that the length of this is one higher than that of stripeEndKeys. */ public ArrayList<ImmutableList<StoreFile>> stripeFiles = new ArrayList<ImmutableList<StoreFile>>(); /** Level 0. The files are in reverse order by seqNum. */ public ImmutableList<StoreFile> level0Files = ImmutableList.<StoreFile>of(); /** Cached list of all files in the structure, to return from some calls */ public ImmutableList<StoreFile> allFilesCached = ImmutableList.<StoreFile>of(); } private State state = null; /** Cached file metadata (or overrides as the case may be) */ private HashMap<StoreFile, byte[]> fileStarts = new HashMap<StoreFile, byte[]>(); private HashMap<StoreFile, byte[]> fileEnds = new HashMap<StoreFile, byte[]>(); /** Normally invalid key is null, but in the map null is the result for "no key"; so use * the following constant value in these maps instead. Note that this is a constant and * we use it to compare by reference when we read from the map. */ private static final byte[] INVALID_KEY_IN_MAP = new byte[0]; private final KVComparator kvComparator; private StripeStoreConfig config; private final int blockingFileCount; public StripeStoreFileManager(KVComparator kvComparator, Configuration conf, StripeStoreConfig config) { this.kvComparator = kvComparator; this.config = config; this.blockingFileCount = conf.getInt(HStore.BLOCKING_STOREFILES_KEY, HStore.DEFAULT_BLOCKING_STOREFILE_COUNT); } @Override public void loadFiles(List<StoreFile> storeFiles) { loadUnclassifiedStoreFiles(storeFiles); } @Override public Collection<StoreFile> getStorefiles() { return state.allFilesCached; } @Override public void insertNewFiles(Collection<StoreFile> sfs) throws IOException { CompactionOrFlushMergeCopy cmc = new CompactionOrFlushMergeCopy(true); cmc.mergeResults(null, sfs); debugDumpState("Added new files"); } @Override public ImmutableCollection<StoreFile> clearFiles() { ImmutableCollection<StoreFile> result = state.allFilesCached; this.state = new State(); this.fileStarts.clear(); this.fileEnds.clear(); return result; } @Override public int getStorefileCount() { return state.allFilesCached.size(); } /** See {@link StoreFileManager#getCandidateFilesForRowKeyBefore(KeyValue)} * for details on this methods. */ @Override public Iterator<StoreFile> getCandidateFilesForRowKeyBefore(final KeyValue targetKey) { KeyBeforeConcatenatedLists result = new KeyBeforeConcatenatedLists(); // Order matters for this call. result.addSublist(state.level0Files); if (!state.stripeFiles.isEmpty()) { int lastStripeIndex = findStripeForRow(targetKey.getRow(), false); for (int stripeIndex = lastStripeIndex; stripeIndex >= 0; --stripeIndex) { result.addSublist(state.stripeFiles.get(stripeIndex)); } } return result.iterator(); } /** See {@link StoreFileManager#getCandidateFilesForRowKeyBefore(KeyValue)} and * {@link StoreFileManager#updateCandidateFilesForRowKeyBefore(Iterator, KeyValue, KeyValue)} * for details on this methods. */ @Override public Iterator<StoreFile> updateCandidateFilesForRowKeyBefore(Iterator<StoreFile> candidateFiles, final KeyValue targetKey, final KeyValue candidate) { KeyBeforeConcatenatedLists.Iterator original = (KeyBeforeConcatenatedLists.Iterator) candidateFiles; assert original != null; ArrayList<List<StoreFile>> components = original.getComponents(); for (int firstIrrelevant = 0; firstIrrelevant < components.size(); ++firstIrrelevant) { StoreFile sf = components.get(firstIrrelevant).get(0); byte[] endKey = endOf(sf); // Entries are ordered as such: L0, then stripes in reverse order. We never remove // level 0; we remove the stripe, and all subsequent ones, as soon as we find the // first one that cannot possibly have better candidates. if (!isInvalid(endKey) && !isOpen(endKey) && (nonOpenRowCompare(endKey, targetKey.getRow()) <= 0)) { original.removeComponents(firstIrrelevant); break; } } return original; } @Override /** * Override of getSplitPoint that determines the split point as the boundary between two * stripes, unless it causes significant imbalance between split sides' sizes. In that * case, the split boundary will be chosen from the middle of one of the stripes to * minimize imbalance. * @return The split point, or null if no split is possible. */ public byte[] getSplitPoint() throws IOException { if (this.getStorefileCount() == 0) return null; if (state.stripeFiles.size() <= 1) { return getSplitPointFromAllFiles(); } int leftIndex = -1, rightIndex = state.stripeFiles.size(); long leftSize = 0, rightSize = 0; long lastLeftSize = 0, lastRightSize = 0; while (rightIndex - 1 != leftIndex) { if (leftSize >= rightSize) { --rightIndex; lastRightSize = getStripeFilesSize(rightIndex); rightSize += lastRightSize; } else { ++leftIndex; lastLeftSize = getStripeFilesSize(leftIndex); leftSize += lastLeftSize; } } if (leftSize == 0 || rightSize == 0) { String errMsg = String.format( "Cannot split on a boundary - left index %d size %d, " + "right index %d size %d", leftIndex, leftSize, rightIndex, rightSize); debugDumpState(errMsg); LOG.warn(errMsg); return getSplitPointFromAllFiles(); } double ratio = (double) rightSize / leftSize; if (ratio < 1) { ratio = 1 / ratio; } if (config.getMaxSplitImbalance() > ratio) return state.stripeEndRows[leftIndex]; // If the difference between the sides is too large, we could get the proportional key on // the a stripe to equalize the difference, but there's no proportional key method at the // moment, and it's not extremely important. // See if we can achieve better ratio if we split the bigger side in half. boolean isRightLarger = rightSize >= leftSize; double newRatio = isRightLarger ? getMidStripeSplitRatio(leftSize, rightSize, lastRightSize) : getMidStripeSplitRatio(rightSize, leftSize, lastLeftSize); if (newRatio < 1) { newRatio = 1 / newRatio; } if (newRatio >= ratio) return state.stripeEndRows[leftIndex]; LOG.debug("Splitting the stripe - ratio w/o split " + ratio + ", ratio with split " + newRatio + " configured ratio " + config.getMaxSplitImbalance()); // Ok, we may get better ratio, get it. return StoreUtils.getLargestFile(state.stripeFiles.get(isRightLarger ? rightIndex : leftIndex)) .getFileSplitPoint(this.kvComparator); } private byte[] getSplitPointFromAllFiles() throws IOException { ConcatenatedLists<StoreFile> sfs = new ConcatenatedLists<StoreFile>(); sfs.addSublist(state.level0Files); sfs.addAllSublists(state.stripeFiles); if (sfs.isEmpty()) return null; return StoreUtils.getLargestFile(sfs).getFileSplitPoint(this.kvComparator); } private double getMidStripeSplitRatio(long smallerSize, long largerSize, long lastLargerSize) { return (double) (largerSize - lastLargerSize / 2f) / (smallerSize + lastLargerSize / 2f); } @Override public Collection<StoreFile> getFilesForScanOrGet(boolean isGet, byte[] startRow, byte[] stopRow) { if (state.stripeFiles.isEmpty()) { return state.level0Files; // There's just L0. } int firstStripe = findStripeForRow(startRow, true); int lastStripe = findStripeForRow(stopRow, false); assert firstStripe <= lastStripe; if (firstStripe == lastStripe && state.level0Files.isEmpty()) { return state.stripeFiles.get(firstStripe); // There's just one stripe we need. } if (firstStripe == 0 && lastStripe == (state.stripeFiles.size() - 1)) { return state.allFilesCached; // We need to read all files. } ConcatenatedLists<StoreFile> result = new ConcatenatedLists<StoreFile>(); result.addAllSublists(state.stripeFiles.subList(firstStripe, lastStripe + 1)); result.addSublist(state.level0Files); return result; } @Override public void addCompactionResults(Collection<StoreFile> compactedFiles, Collection<StoreFile> results) throws IOException { // See class comment for the assumptions we make here. LOG.debug("Attempting to merge compaction results: " + compactedFiles.size() + " files replaced by " + results.size()); // In order to be able to fail in the middle of the operation, we'll operate on lazy // copies and apply the result at the end. CompactionOrFlushMergeCopy cmc = new CompactionOrFlushMergeCopy(false); cmc.mergeResults(compactedFiles, results); debugDumpState("Merged compaction results"); } @Override public int getStoreCompactionPriority() { // If there's only L0, do what the default store does. // If we are in critical priority, do the same - we don't want to trump all stores all // the time due to how many files we have. int fc = getStorefileCount(); if (state.stripeFiles.isEmpty() || (this.blockingFileCount <= fc)) { return this.blockingFileCount - fc; } // If we are in good shape, we don't want to be trumped by all other stores due to how // many files we have, so do an approximate mapping to normal priority range; L0 counts // for all stripes. int l0 = state.level0Files.size(), sc = state.stripeFiles.size(); int priority = (int) Math.ceil(((double) (this.blockingFileCount - fc + l0) / sc) - l0); return (priority <= HStore.PRIORITY_USER) ? (HStore.PRIORITY_USER + 1) : priority; } /** * Gets the total size of all files in the stripe. * @param stripeIndex Stripe index. * @return Size. */ private long getStripeFilesSize(int stripeIndex) { long result = 0; for (StoreFile sf : state.stripeFiles.get(stripeIndex)) { result += sf.getReader().length(); } return result; } /** * Loads initial store files that were picked up from some physical location pertaining to * this store (presumably). Unlike adding files after compaction, assumes empty initial * sets, and is forgiving with regard to stripe constraints - at worst, many/all files will * go to level 0. * @param storeFiles Store files to add. */ private void loadUnclassifiedStoreFiles(List<StoreFile> storeFiles) { LOG.debug("Attempting to load " + storeFiles.size() + " store files."); TreeMap<byte[], ArrayList<StoreFile>> candidateStripes = new TreeMap<byte[], ArrayList<StoreFile>>( MAP_COMPARATOR); ArrayList<StoreFile> level0Files = new ArrayList<StoreFile>(); // Separate the files into tentative stripes; then validate. Currently, we rely on metadata. // If needed, we could dynamically determine the stripes in future. for (StoreFile sf : storeFiles) { byte[] startRow = startOf(sf), endRow = endOf(sf); // Validate the range and put the files into place. if (isInvalid(startRow) || isInvalid(endRow)) { insertFileIntoStripe(level0Files, sf); // No metadata - goes to L0. ensureLevel0Metadata(sf); } else if (!isOpen(startRow) && !isOpen(endRow) && nonOpenRowCompare(startRow, endRow) >= 0) { LOG.error("Unexpected metadata - start row [" + Bytes.toString(startRow) + "], end row [" + Bytes.toString(endRow) + "] in file [" + sf.getPath() + "], pushing to L0"); insertFileIntoStripe(level0Files, sf); // Bad metadata - goes to L0 also. ensureLevel0Metadata(sf); } else { ArrayList<StoreFile> stripe = candidateStripes.get(endRow); if (stripe == null) { stripe = new ArrayList<StoreFile>(); candidateStripes.put(endRow, stripe); } insertFileIntoStripe(stripe, sf); } } // Possible improvement - for variable-count stripes, if all the files are in L0, we can // instead create single, open-ended stripe with all files. boolean hasOverlaps = false; byte[] expectedStartRow = null; // first stripe can start wherever Iterator<Map.Entry<byte[], ArrayList<StoreFile>>> entryIter = candidateStripes.entrySet().iterator(); while (entryIter.hasNext()) { Map.Entry<byte[], ArrayList<StoreFile>> entry = entryIter.next(); ArrayList<StoreFile> files = entry.getValue(); // Validate the file start rows, and remove the bad ones to level 0. for (int i = 0; i < files.size(); ++i) { StoreFile sf = files.get(i); byte[] startRow = startOf(sf); if (expectedStartRow == null) { expectedStartRow = startRow; // ensure that first stripe is still consistent } else if (!rowEquals(expectedStartRow, startRow)) { hasOverlaps = true; LOG.warn("Store file doesn't fit into the tentative stripes - expected to start at [" + Bytes.toString(expectedStartRow) + "], but starts at [" + Bytes.toString(startRow) + "], to L0 it goes"); StoreFile badSf = files.remove(i); insertFileIntoStripe(level0Files, badSf); ensureLevel0Metadata(badSf); --i; } } // Check if any files from the candidate stripe are valid. If so, add a stripe. byte[] endRow = entry.getKey(); if (!files.isEmpty()) { expectedStartRow = endRow; // Next stripe must start exactly at that key. } else { entryIter.remove(); } } // In the end, there must be open ends on two sides. If not, and there were no errors i.e. // files are consistent, they might be coming from a split. We will treat the boundaries // as open keys anyway, and log the message. // If there were errors, we'll play it safe and dump everything into L0. if (!candidateStripes.isEmpty()) { StoreFile firstFile = candidateStripes.firstEntry().getValue().get(0); boolean isOpen = isOpen(startOf(firstFile)) && isOpen(candidateStripes.lastKey()); if (!isOpen) { LOG.warn("The range of the loaded files does not cover full key space: from [" + Bytes.toString(startOf(firstFile)) + "], to [" + Bytes.toString(candidateStripes.lastKey()) + "]"); if (!hasOverlaps) { ensureEdgeStripeMetadata(candidateStripes.firstEntry().getValue(), true); ensureEdgeStripeMetadata(candidateStripes.lastEntry().getValue(), false); } else { LOG.warn("Inconsistent files, everything goes to L0."); for (ArrayList<StoreFile> files : candidateStripes.values()) { for (StoreFile sf : files) { insertFileIntoStripe(level0Files, sf); ensureLevel0Metadata(sf); } } candidateStripes.clear(); } } } // Copy the results into the fields. State state = new State(); state.level0Files = ImmutableList.copyOf(level0Files); state.stripeFiles = new ArrayList<ImmutableList<StoreFile>>(candidateStripes.size()); state.stripeEndRows = new byte[Math.max(0, candidateStripes.size() - 1)][]; ArrayList<StoreFile> newAllFiles = new ArrayList<StoreFile>(level0Files); int i = candidateStripes.size() - 1; for (Map.Entry<byte[], ArrayList<StoreFile>> entry : candidateStripes.entrySet()) { state.stripeFiles.add(ImmutableList.copyOf(entry.getValue())); newAllFiles.addAll(entry.getValue()); if (i > 0) { state.stripeEndRows[state.stripeFiles.size() - 1] = entry.getKey(); } --i; } state.allFilesCached = ImmutableList.copyOf(newAllFiles); this.state = state; debugDumpState("Files loaded"); } private void ensureEdgeStripeMetadata(ArrayList<StoreFile> stripe, boolean isFirst) { HashMap<StoreFile, byte[]> targetMap = isFirst ? fileStarts : fileEnds; for (StoreFile sf : stripe) { targetMap.put(sf, OPEN_KEY); } } private void ensureLevel0Metadata(StoreFile sf) { if (!isInvalid(startOf(sf))) this.fileStarts.put(sf, INVALID_KEY_IN_MAP); if (!isInvalid(endOf(sf))) this.fileEnds.put(sf, INVALID_KEY_IN_MAP); } private void debugDumpState(String string) { if (!LOG.isDebugEnabled()) return; StringBuilder sb = new StringBuilder(); sb.append("\n" + string + "; current stripe state is as such:"); sb.append("\n level 0 with ").append(state.level0Files.size()).append(" files;"); for (int i = 0; i < state.stripeFiles.size(); ++i) { String endRow = (i == state.stripeEndRows.length) ? "(end)" : "[" + Bytes.toString(state.stripeEndRows[i]) + "]"; sb.append("\n stripe ending in ").append(endRow).append(" with ") .append(state.stripeFiles.get(i).size()).append(" files;"); } sb.append("\n").append(getStorefileCount()).append(" files total."); LOG.debug(sb.toString()); } /** * Checks whether the key indicates an open interval boundary (i.e. infinity). */ private static final boolean isOpen(byte[] key) { return key != null && key.length == 0; } /** * Checks whether the key is invalid (e.g. from an L0 file, or non-stripe-compacted files). */ private static final boolean isInvalid(byte[] key) { return key == INVALID_KEY; } /** * Compare two keys for equality. */ private final boolean rowEquals(byte[] k1, byte[] k2) { return kvComparator.matchingRows(k1, 0, k1.length, k2, 0, k2.length); } /** * Compare two keys. Keys must not be open (isOpen(row) == false). */ private final int nonOpenRowCompare(byte[] k1, byte[] k2) { assert !isOpen(k1) && !isOpen(k2); return kvComparator.compareRows(k1, 0, k1.length, k2, 0, k2.length); } /** * Finds the stripe index by end row. */ private final int findStripeIndexByEndRow(byte[] endRow) { assert !isInvalid(endRow); if (isOpen(endRow)) return state.stripeEndRows.length; return Arrays.binarySearch(state.stripeEndRows, endRow, Bytes.BYTES_COMPARATOR); } /** * Finds the stripe index for the stripe containing a row provided externally for get/scan. */ private final int findStripeForRow(byte[] row, boolean isStart) { if (isStart && row == HConstants.EMPTY_START_ROW) return 0; if (!isStart && row == HConstants.EMPTY_END_ROW) return state.stripeFiles.size() - 1; // If there's an exact match below, a stripe ends at "row". Stripe right boundary is // exclusive, so that means the row is in the next stripe; thus, we need to add one to index. // If there's no match, the return value of binarySearch is (-(insertion point) - 1), where // insertion point is the index of the next greater element, or list size if none. The // insertion point happens to be exactly what we need, so we need to add one to the result. return Math.abs(Arrays.binarySearch(state.stripeEndRows, row, Bytes.BYTES_COMPARATOR) + 1); } @Override public final byte[] getStartRow(int stripeIndex) { return (stripeIndex == 0 ? OPEN_KEY : state.stripeEndRows[stripeIndex - 1]); } @Override public final byte[] getEndRow(int stripeIndex) { return (stripeIndex == state.stripeEndRows.length ? OPEN_KEY : state.stripeEndRows[stripeIndex]); } private byte[] startOf(StoreFile sf) { byte[] result = this.fileStarts.get(sf); return result == null ? sf.getMetadataValue(STRIPE_START_KEY) : (result == INVALID_KEY_IN_MAP ? INVALID_KEY : result); } private byte[] endOf(StoreFile sf) { byte[] result = this.fileEnds.get(sf); return result == null ? sf.getMetadataValue(STRIPE_END_KEY) : (result == INVALID_KEY_IN_MAP ? INVALID_KEY : result); } /** * Inserts a file in the correct place (by seqnum) in a stripe copy. * @param stripe Stripe copy to insert into. * @param sf File to insert. */ private static void insertFileIntoStripe(ArrayList<StoreFile> stripe, StoreFile sf) { // The only operation for which sorting of the files matters is KeyBefore. Therefore, // we will store the file in reverse order by seqNum from the outset. for (int insertBefore = 0;; ++insertBefore) { if (insertBefore == stripe.size() || (StoreFile.Comparators.SEQ_ID.compare(sf, stripe.get(insertBefore)) >= 0)) { stripe.add(insertBefore, sf); break; } } } /** * An extension of ConcatenatedLists that has several peculiar properties. * First, one can cut the tail of the logical list by removing last several sub-lists. * Second, items can be removed thru iterator. * Third, if the sub-lists are immutable, they are replaced with mutable copies when needed. * On average KeyBefore operation will contain half the stripes as potential candidates, * but will quickly cut down on them as it finds something in the more likely ones; thus, * the above allow us to avoid unnecessary copying of a bunch of lists. */ private static class KeyBeforeConcatenatedLists extends ConcatenatedLists<StoreFile> { @Override public java.util.Iterator<StoreFile> iterator() { return new Iterator(); } public class Iterator extends ConcatenatedLists<StoreFile>.Iterator { public ArrayList<List<StoreFile>> getComponents() { return components; } public void removeComponents(int startIndex) { List<List<StoreFile>> subList = components.subList(startIndex, components.size()); for (List<StoreFile> entry : subList) { size -= entry.size(); } assert size >= 0; subList.clear(); } @Override public void remove() { if (!this.nextWasCalled) { throw new IllegalStateException("No element to remove"); } this.nextWasCalled = false; List<StoreFile> src = components.get(currentComponent); if (src instanceof ImmutableList<?>) { src = new ArrayList<StoreFile>(src); components.set(currentComponent, src); } src.remove(indexWithinComponent); --size; --indexWithinComponent; if (src.isEmpty()) { components.remove(currentComponent); // indexWithinComponent is already -1 here. } } } } /** * Non-static helper class for merging compaction or flush results. * Since we want to merge them atomically (more or less), it operates on lazy copies, * then creates a new state object and puts it in place. */ private class CompactionOrFlushMergeCopy { private ArrayList<List<StoreFile>> stripeFiles = null; private ArrayList<StoreFile> level0Files = null; private ArrayList<byte[]> stripeEndRows = null; private Collection<StoreFile> compactedFiles = null; private Collection<StoreFile> results = null; private List<StoreFile> l0Results = new ArrayList<StoreFile>(); private final boolean isFlush; public CompactionOrFlushMergeCopy(boolean isFlush) { // Create a lazy mutable copy (other fields are so lazy they start out as nulls). this.stripeFiles = new ArrayList<List<StoreFile>>(StripeStoreFileManager.this.state.stripeFiles); this.isFlush = isFlush; } public void mergeResults(Collection<StoreFile> compactedFiles, Collection<StoreFile> results) throws IOException { assert this.compactedFiles == null && this.results == null; this.compactedFiles = compactedFiles; this.results = results; // Do logical processing. if (!isFlush) removeCompactedFiles(); TreeMap<byte[], StoreFile> newStripes = processResults(); if (newStripes != null) { processNewCandidateStripes(newStripes); } // Create new state and update parent. State state = createNewState(); StripeStoreFileManager.this.state = state; updateMetadataMaps(); } private State createNewState() { State oldState = StripeStoreFileManager.this.state; // Stripe count should be the same unless the end rows changed. assert oldState.stripeFiles.size() == this.stripeFiles.size() || this.stripeEndRows != null; State newState = new State(); newState.level0Files = (this.level0Files == null) ? oldState.level0Files : ImmutableList.copyOf(this.level0Files); newState.stripeEndRows = (this.stripeEndRows == null) ? oldState.stripeEndRows : this.stripeEndRows.toArray(new byte[this.stripeEndRows.size()][]); newState.stripeFiles = new ArrayList<ImmutableList<StoreFile>>(this.stripeFiles.size()); for (List<StoreFile> newStripe : this.stripeFiles) { newState.stripeFiles .add(newStripe instanceof ImmutableList<?> ? (ImmutableList<StoreFile>) newStripe : ImmutableList.copyOf(newStripe)); } List<StoreFile> newAllFiles = new ArrayList<StoreFile>(oldState.allFilesCached); if (!isFlush) newAllFiles.removeAll(compactedFiles); newAllFiles.addAll(results); newState.allFilesCached = ImmutableList.copyOf(newAllFiles); return newState; } private void updateMetadataMaps() { StripeStoreFileManager parent = StripeStoreFileManager.this; if (!isFlush) { for (StoreFile sf : this.compactedFiles) { parent.fileStarts.remove(sf); parent.fileEnds.remove(sf); } } if (this.l0Results != null) { for (StoreFile sf : this.l0Results) { parent.ensureLevel0Metadata(sf); } } } /** * @param index Index of the stripe we need. * @return A lazy stripe copy from current stripes. */ private final ArrayList<StoreFile> getStripeCopy(int index) { List<StoreFile> stripeCopy = this.stripeFiles.get(index); ArrayList<StoreFile> result = null; if (stripeCopy instanceof ImmutableList<?>) { result = new ArrayList<StoreFile>(stripeCopy); this.stripeFiles.set(index, result); } else { result = (ArrayList<StoreFile>) stripeCopy; } return result; } /** * @return A lazy L0 copy from current state. */ private final ArrayList<StoreFile> getLevel0Copy() { if (this.level0Files == null) { this.level0Files = new ArrayList<StoreFile>(StripeStoreFileManager.this.state.level0Files); } return this.level0Files; } /** * Process new files, and add them either to the structure of existing stripes, * or to the list of new candidate stripes. * @return New candidate stripes. */ private TreeMap<byte[], StoreFile> processResults() throws IOException { TreeMap<byte[], StoreFile> newStripes = null; for (StoreFile sf : this.results) { byte[] startRow = startOf(sf), endRow = endOf(sf); if (isInvalid(endRow) || isInvalid(startRow)) { if (!isFlush) { LOG.warn("The newly compacted file doesn't have stripes set: " + sf.getPath()); } insertFileIntoStripe(getLevel0Copy(), sf); this.l0Results.add(sf); continue; } if (!this.stripeFiles.isEmpty()) { int stripeIndex = findStripeIndexByEndRow(endRow); if ((stripeIndex >= 0) && rowEquals(getStartRow(stripeIndex), startRow)) { // Simple/common case - add file to an existing stripe. insertFileIntoStripe(getStripeCopy(stripeIndex), sf); continue; } } // Make a new candidate stripe. if (newStripes == null) { newStripes = new TreeMap<byte[], StoreFile>(MAP_COMPARATOR); } StoreFile oldSf = newStripes.put(endRow, sf); if (oldSf != null) { throw new IOException("Compactor has produced multiple files for the stripe ending in [" + Bytes.toString(endRow) + "], found " + sf.getPath() + " and " + oldSf.getPath()); } } return newStripes; } /** * Remove compacted files. * @param compactedFiles Compacted files. */ private void removeCompactedFiles() throws IOException { for (StoreFile oldFile : this.compactedFiles) { byte[] oldEndRow = endOf(oldFile); List<StoreFile> source = null; if (isInvalid(oldEndRow)) { source = getLevel0Copy(); } else { int stripeIndex = findStripeIndexByEndRow(oldEndRow); if (stripeIndex < 0) { throw new IOException("An allegedly compacted file [" + oldFile + "] does not belong" + " to a known stripe (end row - [" + Bytes.toString(oldEndRow) + "])"); } source = getStripeCopy(stripeIndex); } if (!source.remove(oldFile)) { throw new IOException("An allegedly compacted file [" + oldFile + "] was not found"); } } } /** * See {@link #addCompactionResults(Collection, Collection)} - updates the stripe list with * new candidate stripes/removes old stripes; produces new set of stripe end rows. * @param newStripes New stripes - files by end row. */ private void processNewCandidateStripes(TreeMap<byte[], StoreFile> newStripes) throws IOException { // Validate that the removed and added aggregate ranges still make for a full key space. boolean hasStripes = !this.stripeFiles.isEmpty(); this.stripeEndRows = new ArrayList<byte[]>( Arrays.asList(StripeStoreFileManager.this.state.stripeEndRows)); int removeFrom = 0; byte[] firstStartRow = startOf(newStripes.firstEntry().getValue()); byte[] lastEndRow = newStripes.lastKey(); if (!hasStripes && (!isOpen(firstStartRow) || !isOpen(lastEndRow))) { throw new IOException("Newly created stripes do not cover the entire key space."); } boolean canAddNewStripes = true; Collection<StoreFile> filesForL0 = null; if (hasStripes) { // Determine which stripes will need to be removed because they conflict with new stripes. // The new boundaries should match old stripe boundaries, so we should get exact matches. if (isOpen(firstStartRow)) { removeFrom = 0; } else { removeFrom = findStripeIndexByEndRow(firstStartRow); if (removeFrom < 0) throw new IOException("Compaction is trying to add a bad range."); ++removeFrom; } int removeTo = findStripeIndexByEndRow(lastEndRow); if (removeTo < 0) throw new IOException("Compaction is trying to add a bad range."); // See if there are files in the stripes we are trying to replace. ArrayList<StoreFile> conflictingFiles = new ArrayList<StoreFile>(); for (int removeIndex = removeTo; removeIndex >= removeFrom; --removeIndex) { conflictingFiles.addAll(this.stripeFiles.get(removeIndex)); } if (!conflictingFiles.isEmpty()) { // This can be caused by two things - concurrent flush into stripes, or a bug. // Unfortunately, we cannot tell them apart without looking at timing or something // like that. We will assume we are dealing with a flush and dump it into L0. if (isFlush) { long newSize = StripeCompactionPolicy.getTotalFileSize(newStripes.values()); LOG.warn("Stripes were created by a flush, but results of size " + newSize + " cannot be added because the stripes have changed"); canAddNewStripes = false; filesForL0 = newStripes.values(); } else { long oldSize = StripeCompactionPolicy.getTotalFileSize(conflictingFiles); LOG.info(conflictingFiles.size() + " conflicting files (likely created by a flush) " + " of size " + oldSize + " are moved to L0 due to concurrent stripe change"); filesForL0 = conflictingFiles; } if (filesForL0 != null) { for (StoreFile sf : filesForL0) { insertFileIntoStripe(getLevel0Copy(), sf); } l0Results.addAll(filesForL0); } } if (canAddNewStripes) { // Remove old empty stripes. int originalCount = this.stripeFiles.size(); for (int removeIndex = removeTo; removeIndex >= removeFrom; --removeIndex) { if (removeIndex != originalCount - 1) { this.stripeEndRows.remove(removeIndex); } this.stripeFiles.remove(removeIndex); } } } if (!canAddNewStripes) return; // Files were already put into L0. // Now, insert new stripes. The total ranges match, so we can insert where we removed. byte[] previousEndRow = null; int insertAt = removeFrom; for (Map.Entry<byte[], StoreFile> newStripe : newStripes.entrySet()) { if (previousEndRow != null) { // Validate that the ranges are contiguous. assert !isOpen(previousEndRow); byte[] startRow = startOf(newStripe.getValue()); if (!rowEquals(previousEndRow, startRow)) { throw new IOException("The new stripes produced by " + (isFlush ? "flush" : "compaction") + " are not contiguous"); } } // Add the new stripe. ArrayList<StoreFile> tmp = new ArrayList<StoreFile>(); tmp.add(newStripe.getValue()); stripeFiles.add(insertAt, tmp); previousEndRow = newStripe.getKey(); if (!isOpen(previousEndRow)) { stripeEndRows.add(insertAt, previousEndRow); } ++insertAt; } } } @Override public List<StoreFile> getLevel0Files() { return this.state.level0Files; } @Override public List<byte[]> getStripeBoundaries() { if (this.state.stripeFiles.isEmpty()) return new ArrayList<byte[]>(); ArrayList<byte[]> result = new ArrayList<byte[]>(this.state.stripeEndRows.length + 2); result.add(OPEN_KEY); for (int i = 0; i < this.state.stripeEndRows.length; ++i) { result.add(this.state.stripeEndRows[i]); } result.add(OPEN_KEY); return result; } @Override public ArrayList<ImmutableList<StoreFile>> getStripes() { return this.state.stripeFiles; } @Override public int getStripeCount() { return this.state.stripeFiles.size(); } @Override public Collection<StoreFile> getUnneededFiles(long maxTs, List<StoreFile> filesCompacting) { // 1) We can never get rid of the last file which has the maximum seqid in a stripe. // 2) Files that are not the latest can't become one due to (1), so the rest are fair game. State state = this.state; Collection<StoreFile> expiredStoreFiles = null; for (ImmutableList<StoreFile> stripe : state.stripeFiles) { expiredStoreFiles = findExpiredFiles(stripe, maxTs, filesCompacting, expiredStoreFiles); } return findExpiredFiles(state.level0Files, maxTs, filesCompacting, expiredStoreFiles); } private Collection<StoreFile> findExpiredFiles(ImmutableList<StoreFile> stripe, long maxTs, List<StoreFile> filesCompacting, Collection<StoreFile> expiredStoreFiles) { // Order by seqnum is reversed. for (int i = 1; i < stripe.size(); ++i) { StoreFile sf = stripe.get(i); long fileTs = sf.getReader().getMaxTimestamp(); if (fileTs < maxTs && !filesCompacting.contains(sf)) { LOG.info("Found an expired store file: " + sf.getPath() + " whose maxTimeStamp is " + fileTs + ", which is below " + maxTs); if (expiredStoreFiles == null) { expiredStoreFiles = new ArrayList<StoreFile>(); } expiredStoreFiles.add(sf); } } return expiredStoreFiles; } }