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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.regionserver.compactions;
19  
20  import com.google.common.io.Closeables;
21  
22  import java.io.IOException;
23  import java.io.InterruptedIOException;
24  import java.security.PrivilegedExceptionAction;
25  import java.util.ArrayList;
26  import java.util.Collection;
27  import java.util.Collections;
28  import java.util.List;
29  import java.util.Map;
30  import java.util.concurrent.atomic.AtomicInteger;
31  
32  import org.apache.commons.logging.Log;
33  import org.apache.commons.logging.LogFactory;
34  import org.apache.hadoop.conf.Configuration;
35  import org.apache.hadoop.fs.Path;
36  import org.apache.hadoop.hbase.Cell;
37  import org.apache.hadoop.hbase.CellUtil;
38  import org.apache.hadoop.hbase.HConstants;
39  import org.apache.hadoop.hbase.KeyValueUtil;
40  import org.apache.hadoop.hbase.classification.InterfaceAudience;
41  import org.apache.hadoop.hbase.client.Scan;
42  import org.apache.hadoop.hbase.io.compress.Compression;
43  import org.apache.hadoop.hbase.io.hfile.HFile.FileInfo;
44  import org.apache.hadoop.hbase.io.hfile.HFileWriterV2;
45  import org.apache.hadoop.hbase.regionserver.HStore;
46  import org.apache.hadoop.hbase.regionserver.InternalScanner;
47  import org.apache.hadoop.hbase.regionserver.ScanType;
48  import org.apache.hadoop.hbase.regionserver.ScannerContext;
49  import org.apache.hadoop.hbase.regionserver.Store;
50  import org.apache.hadoop.hbase.regionserver.StoreFile;
51  import org.apache.hadoop.hbase.regionserver.StoreFile.Writer;
52  import org.apache.hadoop.hbase.regionserver.StoreFileScanner;
53  import org.apache.hadoop.hbase.regionserver.StoreScanner;
54  import org.apache.hadoop.hbase.regionserver.TimeRangeTracker;
55  import org.apache.hadoop.hbase.regionserver.compactions.Compactor.CellSink;
56  import org.apache.hadoop.hbase.security.User;
57  import org.apache.hadoop.hbase.util.Bytes;
58  import org.apache.hadoop.hbase.util.Writables;
59  import org.apache.hadoop.util.StringUtils;
60  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
61  import org.apache.hadoop.util.StringUtils.TraditionalBinaryPrefix;
62  
63  /**
64   * A compactor is a compaction algorithm associated a given policy. Base class also contains
65   * reusable parts for implementing compactors (what is common and what isn't is evolving).
66   */
67  @InterfaceAudience.Private
68  public abstract class Compactor<T extends CellSink> {
69    private static final Log LOG = LogFactory.getLog(Compactor.class);
70  
71    protected volatile CompactionProgress progress;
72  
73    protected final Configuration conf;
74    protected final Store store;
75  
76    protected final int compactionKVMax;
77    protected final Compression.Algorithm compactionCompression;
78  
79    /** specify how many days to keep MVCC values during major compaction **/ 
80    protected final int keepSeqIdPeriod;
81  
82    //TODO: depending on Store is not good but, realistically, all compactors currently do.
83    Compactor(final Configuration conf, final Store store) {
84      this.conf = conf;
85      this.store = store;
86      this.compactionKVMax =
87        this.conf.getInt(HConstants.COMPACTION_KV_MAX, HConstants.COMPACTION_KV_MAX_DEFAULT);
88      this.compactionCompression = (this.store.getFamily() == null) ?
89          Compression.Algorithm.NONE : this.store.getFamily().getCompactionCompression();
90      this.keepSeqIdPeriod = Math.max(this.conf.getInt(HConstants.KEEP_SEQID_PERIOD, 
91        HConstants.MIN_KEEP_SEQID_PERIOD), HConstants.MIN_KEEP_SEQID_PERIOD);
92    }
93  
94    public interface CellSink {
95      void append(Cell cell) throws IOException;
96    }
97  
98    protected interface CellSinkFactory<S> {
99      S createWriter(InternalScanner scanner, FileDetails fd, boolean shouldDropBehind)
100         throws IOException;
101   }
102 
103   public CompactionProgress getProgress() {
104     return this.progress;
105   }
106 
107   /** The sole reason this class exists is that java has no ref/out/pointer parameters. */
108   protected static class FileDetails {
109     /** Maximum key count after compaction (for blooms) */
110     public long maxKeyCount = 0;
111     /** Earliest put timestamp if major compaction */
112     public long earliestPutTs = HConstants.LATEST_TIMESTAMP;
113     /** Latest put timestamp */
114     public long latestPutTs = HConstants.LATEST_TIMESTAMP;
115     /** The last key in the files we're compacting. */
116     public long maxSeqId = 0;
117     /** Latest memstore read point found in any of the involved files */
118     public long maxMVCCReadpoint = 0;
119     /** Max tags length**/
120     public int maxTagsLength = 0;
121     /** Min SeqId to keep during a major compaction **/
122     public long minSeqIdToKeep = 0;
123   }
124 
125   /**
126    * Extracts some details about the files to compact that are commonly needed by compactors.
127    * @param filesToCompact Files.
128    * @param allFiles Whether all files are included for compaction
129    * @return The result.
130    */
131   protected FileDetails getFileDetails(
132       Collection<StoreFile> filesToCompact, boolean allFiles) throws IOException {
133     FileDetails fd = new FileDetails();
134     long oldestHFileTimeStampToKeepMVCC = System.currentTimeMillis() - 
135       (1000L * 60 * 60 * 24 * this.keepSeqIdPeriod);  
136 
137     for (StoreFile file : filesToCompact) {
138       if(allFiles && (file.getModificationTimeStamp() < oldestHFileTimeStampToKeepMVCC)) {
139         // when isAllFiles is true, all files are compacted so we can calculate the smallest 
140         // MVCC value to keep
141         if(fd.minSeqIdToKeep < file.getMaxMemstoreTS()) {
142           fd.minSeqIdToKeep = file.getMaxMemstoreTS();
143         }
144       }
145       long seqNum = file.getMaxSequenceId();
146       fd.maxSeqId = Math.max(fd.maxSeqId, seqNum);
147       StoreFile.Reader r = file.getReader();
148       if (r == null) {
149         LOG.warn("Null reader for " + file.getPath());
150         continue;
151       }
152       // NOTE: use getEntries when compacting instead of getFilterEntries, otherwise under-sized
153       // blooms can cause progress to be miscalculated or if the user switches bloom
154       // type (e.g. from ROW to ROWCOL)
155       long keyCount = r.getEntries();
156       fd.maxKeyCount += keyCount;
157       // calculate the latest MVCC readpoint in any of the involved store files
158       Map<byte[], byte[]> fileInfo = r.loadFileInfo();
159       byte[] tmp = null;
160       // Get and set the real MVCCReadpoint for bulk loaded files, which is the
161       // SeqId number.
162       if (r.isBulkLoaded()) {
163         fd.maxMVCCReadpoint = Math.max(fd.maxMVCCReadpoint, r.getSequenceID());
164       }
165       else {
166         tmp = fileInfo.get(HFileWriterV2.MAX_MEMSTORE_TS_KEY);
167         if (tmp != null) {
168           fd.maxMVCCReadpoint = Math.max(fd.maxMVCCReadpoint, Bytes.toLong(tmp));
169         }
170       }
171       tmp = fileInfo.get(FileInfo.MAX_TAGS_LEN);
172       if (tmp != null) {
173         fd.maxTagsLength = Math.max(fd.maxTagsLength, Bytes.toInt(tmp));
174       }
175       // If required, calculate the earliest put timestamp of all involved storefiles.
176       // This is used to remove family delete marker during compaction.
177       long earliestPutTs = 0;
178       if (allFiles) {
179         tmp = fileInfo.get(StoreFile.EARLIEST_PUT_TS);
180         if (tmp == null) {
181           // There's a file with no information, must be an old one
182           // assume we have very old puts
183           fd.earliestPutTs = earliestPutTs = HConstants.OLDEST_TIMESTAMP;
184         } else {
185           earliestPutTs = Bytes.toLong(tmp);
186           fd.earliestPutTs = Math.min(fd.earliestPutTs, earliestPutTs);
187         }
188       }
189       tmp = fileInfo.get(StoreFile.TIMERANGE_KEY);
190       TimeRangeTracker trt = new TimeRangeTracker();
191       if (tmp == null) {
192         fd.latestPutTs = HConstants.LATEST_TIMESTAMP;
193       } else {
194         Writables.copyWritable(tmp, trt);
195         fd.latestPutTs = trt.getMaximumTimestamp();
196       }
197       if (LOG.isDebugEnabled()) {
198         LOG.debug("Compacting " + file +
199           ", keycount=" + keyCount +
200           ", bloomtype=" + r.getBloomFilterType().toString() +
201           ", size=" + TraditionalBinaryPrefix.long2String(r.length(), "", 1) +
202           ", encoding=" + r.getHFileReader().getDataBlockEncoding() +
203           ", seqNum=" + seqNum +
204           (allFiles ? ", earliestPutTs=" + earliestPutTs: ""));
205       }
206     }
207     return fd;
208   }
209 
210   /**
211    * Creates file scanners for compaction.
212    * @param filesToCompact Files.
213    * @return Scanners.
214    */
215   protected List<StoreFileScanner> createFileScanners(
216       final Collection<StoreFile> filesToCompact, long smallestReadPoint) throws IOException {
217     return StoreFileScanner.getScannersForStoreFiles(filesToCompact, false, false, true,
218       smallestReadPoint);
219   }
220 
221   protected long getSmallestReadPoint() {
222     return store.getSmallestReadPoint();
223   }
224 
225   protected interface InternalScannerFactory {
226 
227     ScanType getScanType(CompactionRequest request);
228 
229     InternalScanner createScanner(List<StoreFileScanner> scanners, ScanType scanType,
230         FileDetails fd, long smallestReadPoint) throws IOException;
231   }
232 
233   protected final InternalScannerFactory defaultScannerFactory = new InternalScannerFactory() {
234 
235     @Override
236     public ScanType getScanType(CompactionRequest request) {
237       return request.isAllFiles() ? ScanType.COMPACT_DROP_DELETES
238           : ScanType.COMPACT_RETAIN_DELETES;
239     }
240 
241     @Override
242     public InternalScanner createScanner(List<StoreFileScanner> scanners, ScanType scanType,
243         FileDetails fd, long smallestReadPoint) throws IOException {
244       return Compactor.this.createScanner(store, scanners, scanType, smallestReadPoint,
245         fd.earliestPutTs);
246     }
247   };
248 
249   /**
250    * Creates a writer for a new file in a temporary directory.
251    * @param fd The file details.
252    * @return Writer for a new StoreFile in the tmp dir.
253    * @throws IOException if creation failed
254    */
255   protected Writer createTmpWriter(FileDetails fd, boolean shouldDropBehind) throws IOException {
256     // When all MVCC readpoints are 0, don't write them.
257     // See HBASE-8166, HBASE-12600, and HBASE-13389.
258     return store.createWriterInTmp(fd.maxKeyCount, this.compactionCompression,
259     /* isCompaction = */true,
260     /* includeMVCCReadpoint = */fd.maxMVCCReadpoint > 0,
261     /* includesTags = */fd.maxTagsLength > 0);
262   }
263 
264   protected List<Path> compact(final CompactionRequest request,
265       InternalScannerFactory scannerFactory, CellSinkFactory<T> sinkFactory,
266       CompactionThroughputController throughputController, User user) throws IOException {
267     FileDetails fd = getFileDetails(request.getFiles(), request.isAllFiles());
268     this.progress = new CompactionProgress(fd.maxKeyCount);
269 
270     // Find the smallest read point across all the Scanners.
271     long smallestReadPoint = getSmallestReadPoint();
272 
273     List<StoreFileScanner> scanners;
274     Collection<StoreFile> readersToClose;
275     T writer = null;
276     if (this.conf.getBoolean("hbase.regionserver.compaction.private.readers", true)) {
277       // clone all StoreFiles, so we'll do the compaction on a independent copy of StoreFiles,
278       // HFiles, and their readers
279       readersToClose = new ArrayList<StoreFile>(request.getFiles().size());
280       for (StoreFile f : request.getFiles()) {
281         readersToClose.add(f.cloneForReader());
282       }
283       scanners = createFileScanners(readersToClose, smallestReadPoint);
284         // store.throttleCompaction(request.getSize())
285     } else {
286       readersToClose = Collections.emptyList();
287       scanners = createFileScanners(request.getFiles(), smallestReadPoint);
288         // store.throttleCompaction(request.getSize())
289     }
290     InternalScanner scanner = null;
291     boolean finished = false;
292     try {
293       /* Include deletes, unless we are doing a major compaction */
294       ScanType scanType = scannerFactory.getScanType(request);
295       scanner = preCreateCoprocScanner(request, scanType, fd.earliestPutTs, scanners, user);
296       if (scanner == null) {
297         scanner = scannerFactory.createScanner(scanners, scanType, fd, smallestReadPoint);
298       }
299       scanner = postCreateCoprocScanner(request, scanType, scanner, user);
300       if (scanner == null) {
301         // NULL scanner returned from coprocessor hooks means skip normal processing.
302         return new ArrayList<Path>();
303       }
304       boolean cleanSeqId = false;
305       if (fd.minSeqIdToKeep > 0) {
306         smallestReadPoint = Math.min(fd.minSeqIdToKeep, smallestReadPoint);
307         cleanSeqId = true;
308       }
309       writer = sinkFactory.createWriter(scanner, fd, store.throttleCompaction(request.getSize()));
310       finished =
311           performCompaction(fd, scanner, writer, smallestReadPoint, cleanSeqId,
312             throughputController, request.isAllFiles());
313       if (!finished) {
314         throw new InterruptedIOException("Aborting compaction of store " + store + " in region "
315             + store.getRegionInfo().getRegionNameAsString() + " because it was interrupted.");
316       }
317     } finally {
318       Closeables.close(scanner, true);
319       for (StoreFile f : readersToClose) {
320         try {
321           f.closeReader(true);
322         } catch (IOException e) {
323           LOG.warn("Exception closing " + f, e);
324         }
325       }
326       if (!finished && writer != null) {
327         abortWriter(writer);
328       }
329     }
330     assert finished : "We should have exited the method on all error paths";
331     assert writer != null : "Writer should be non-null if no error";
332     return commitWriter(writer, fd, request);
333   }
334 
335   protected abstract List<Path> commitWriter(T writer, FileDetails fd, CompactionRequest request)
336       throws IOException;
337 
338   protected abstract void abortWriter(T writer) throws IOException;
339 
340   /**
341    * Calls coprocessor, if any, to create compaction scanner - before normal scanner creation.
342    * @param request Compaction request.
343    * @param scanType Scan type.
344    * @param earliestPutTs Earliest put ts.
345    * @param scanners File scanners for compaction files.
346    * @return Scanner override by coprocessor; null if not overriding.
347    */
348   protected InternalScanner preCreateCoprocScanner(final CompactionRequest request,
349       ScanType scanType, long earliestPutTs,  List<StoreFileScanner> scanners) throws IOException {
350     return preCreateCoprocScanner(request, scanType, earliestPutTs, scanners, null);
351   }
352 
353   protected InternalScanner preCreateCoprocScanner(final CompactionRequest request,
354       final ScanType scanType, final long earliestPutTs, final List<StoreFileScanner> scanners,
355       User user) throws IOException {
356     if (store.getCoprocessorHost() == null) return null;
357     if (user == null) {
358       return store.getCoprocessorHost().preCompactScannerOpen(store, scanners, scanType,
359         earliestPutTs, request);
360     } else {
361       try {
362         return user.getUGI().doAs(new PrivilegedExceptionAction<InternalScanner>() {
363           @Override
364           public InternalScanner run() throws Exception {
365             return store.getCoprocessorHost().preCompactScannerOpen(store, scanners,
366               scanType, earliestPutTs, request);
367           }
368         });
369       } catch (InterruptedException ie) {
370         InterruptedIOException iioe = new InterruptedIOException();
371         iioe.initCause(ie);
372         throw iioe;
373       }
374     }
375   }
376 
377   /**
378    * Calls coprocessor, if any, to create scanners - after normal scanner creation.
379    * @param request Compaction request.
380    * @param scanType Scan type.
381    * @param scanner The default scanner created for compaction.
382    * @return Scanner scanner to use (usually the default); null if compaction should not proceed.
383    */
384    protected InternalScanner postCreateCoprocScanner(final CompactionRequest request,
385        final ScanType scanType, final InternalScanner scanner, User user) throws IOException {
386     if (store.getCoprocessorHost() == null) {
387       return scanner;
388     }
389     if (user == null) {
390       return store.getCoprocessorHost().preCompact(store, scanner, scanType, request);
391     } else {
392       try {
393         return user.getUGI().doAs(new PrivilegedExceptionAction<InternalScanner>() {
394           @Override
395           public InternalScanner run() throws Exception {
396             return store.getCoprocessorHost().preCompact(store, scanner, scanType, request);
397           }
398         });
399       } catch (InterruptedException ie) {
400         InterruptedIOException iioe = new InterruptedIOException();
401         iioe.initCause(ie);
402         throw iioe;
403       }
404     }
405   }
406 
407   /**
408    * Used to prevent compaction name conflict when multiple compactions running parallel on the
409    * same store.
410    */
411   private static final AtomicInteger NAME_COUNTER = new AtomicInteger(0);
412 
413   private String generateCompactionName() {
414     int counter;
415     for (;;) {
416       counter = NAME_COUNTER.get();
417       int next = counter == Integer.MAX_VALUE ? 0 : counter + 1;
418       if (NAME_COUNTER.compareAndSet(counter, next)) {
419         break;
420       }
421     }
422     return store.getRegionInfo().getRegionNameAsString() + "#"
423         + store.getFamily().getNameAsString() + "#" + counter;
424   }
425   /**
426    * Performs the compaction.
427    * @param fd FileDetails of cell sink writer
428    * @param scanner Where to read from.
429    * @param writer Where to write to.
430    * @param smallestReadPoint Smallest read point.
431    * @param cleanSeqId When true, remove seqId(used to be mvcc) value which is <= smallestReadPoint
432    * @param major Is a major compaction.
433    * @return Whether compaction ended; false if it was interrupted for some reason.
434    */
435   protected boolean performCompaction(FileDetails fd, InternalScanner scanner, CellSink writer,
436       long smallestReadPoint, boolean cleanSeqId,
437       CompactionThroughputController throughputController, boolean major) throws IOException {
438     long bytesWritten = 0;
439     long bytesWrittenProgress = 0;
440     // Since scanner.next() can return 'false' but still be delivering data,
441     // we have to use a do/while loop.
442     List<Cell> cells = new ArrayList<Cell>();
443     long closeCheckInterval = HStore.getCloseCheckInterval();
444     long lastMillis = 0;
445     if (LOG.isDebugEnabled()) {
446       lastMillis = EnvironmentEdgeManager.currentTime();
447     }
448     String compactionName = generateCompactionName();
449     long now = 0;
450     boolean hasMore;
451     ScannerContext scannerContext =
452         ScannerContext.newBuilder().setBatchLimit(compactionKVMax).build();
453 
454     throughputController.start(compactionName);
455     try {
456       do {
457         hasMore = scanner.next(cells, scannerContext);
458         if (LOG.isDebugEnabled()) {
459           now = EnvironmentEdgeManager.currentTime();
460         }
461         // output to writer:
462         for (Cell c : cells) {
463           if (cleanSeqId && c.getSequenceId() <= smallestReadPoint) {
464             CellUtil.setSequenceId(c, 0);
465           }
466           writer.append(c);
467           int len = KeyValueUtil.length(c);
468           ++progress.currentCompactedKVs;
469           progress.totalCompactedSize += len;
470           if (LOG.isDebugEnabled()) {
471             bytesWrittenProgress += len;
472           }
473           throughputController.control(compactionName, len);
474           // check periodically to see if a system stop is requested
475           if (closeCheckInterval > 0) {
476             bytesWritten += len;
477             if (bytesWritten > closeCheckInterval) {
478               bytesWritten = 0;
479               if (!store.areWritesEnabled()) {
480                 progress.cancel();
481                 return false;
482               }
483             }
484           }
485         }
486         // Log the progress of long running compactions every minute if
487         // logging at DEBUG level
488         if (LOG.isDebugEnabled()) {
489           if ((now - lastMillis) >= 60 * 1000) {
490             LOG.debug("Compaction progress: "
491                 + compactionName
492                 + " "
493                 + progress
494                 + String.format(", rate=%.2f kB/sec", (bytesWrittenProgress / 1024.0)
495                     / ((now - lastMillis) / 1000.0)) + ", throughputController is "
496                 + throughputController);
497             lastMillis = now;
498             bytesWrittenProgress = 0;
499           }
500         }
501         cells.clear();
502       } while (hasMore);
503     } catch (InterruptedException e) {
504       progress.cancel();
505       throw new InterruptedIOException("Interrupted while control throughput of compacting "
506           + compactionName);
507     } finally {
508       throughputController.finish(compactionName);
509     }
510     progress.complete();
511     return true;
512   }
513 
514   /**
515    * @param store store
516    * @param scanners Store file scanners.
517    * @param scanType Scan type.
518    * @param smallestReadPoint Smallest MVCC read point.
519    * @param earliestPutTs Earliest put across all files.
520    * @return A compaction scanner.
521    */
522   protected InternalScanner createScanner(Store store, List<StoreFileScanner> scanners,
523       ScanType scanType, long smallestReadPoint, long earliestPutTs) throws IOException {
524     Scan scan = new Scan();
525     scan.setMaxVersions(store.getFamily().getMaxVersions());
526     return new StoreScanner(store, store.getScanInfo(), scan, scanners,
527         scanType, smallestReadPoint, earliestPutTs);
528   }
529 
530   /**
531    * @param store The store.
532    * @param scanners Store file scanners.
533    * @param smallestReadPoint Smallest MVCC read point.
534    * @param earliestPutTs Earliest put across all files.
535    * @param dropDeletesFromRow Drop deletes starting with this row, inclusive. Can be null.
536    * @param dropDeletesToRow Drop deletes ending with this row, exclusive. Can be null.
537    * @return A compaction scanner.
538    */
539   protected InternalScanner createScanner(Store store, List<StoreFileScanner> scanners,
540      long smallestReadPoint, long earliestPutTs, byte[] dropDeletesFromRow,
541      byte[] dropDeletesToRow) throws IOException {
542     Scan scan = new Scan();
543     scan.setMaxVersions(store.getFamily().getMaxVersions());
544     return new StoreScanner(store, store.getScanInfo(), scan, scanners, smallestReadPoint,
545         earliestPutTs, dropDeletesFromRow, dropDeletesToRow);
546   }
547 
548   /**
549    * Appends the metadata and closes the writer.
550    * @param writer The current store writer.
551    * @param fd The file details.
552    * @param isMajor Is a major compaction.
553    * @throws IOException
554    */
555   protected void appendMetadataAndCloseWriter(StoreFile.Writer writer, FileDetails fd,
556       boolean isMajor) throws IOException {
557     writer.appendMetadata(fd.maxSeqId, isMajor);
558     writer.close();
559   }
560 }