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19 package org.apache.hadoop.hbase.master;
20
21 import java.io.FileNotFoundException;
22 import java.io.IOException;
23 import java.util.Comparator;
24 import java.util.HashSet;
25 import java.util.Map;
26 import java.util.TreeMap;
27 import java.util.concurrent.atomic.AtomicBoolean;
28 import java.util.concurrent.atomic.AtomicInteger;
29
30 import org.apache.commons.logging.Log;
31 import org.apache.commons.logging.LogFactory;
32 import org.apache.hadoop.fs.FileSystem;
33 import org.apache.hadoop.fs.Path;
34 import org.apache.hadoop.hbase.HColumnDescriptor;
35 import org.apache.hadoop.hbase.HConstants;
36 import org.apache.hadoop.hbase.HRegionInfo;
37 import org.apache.hadoop.hbase.HTableDescriptor;
38 import org.apache.hadoop.hbase.MetaTableAccessor;
39 import org.apache.hadoop.hbase.ScheduledChore;
40 import org.apache.hadoop.hbase.Server;
41 import org.apache.hadoop.hbase.TableName;
42 import org.apache.hadoop.hbase.backup.HFileArchiver;
43 import org.apache.hadoop.hbase.classification.InterfaceAudience;
44 import org.apache.hadoop.hbase.client.Connection;
45 import org.apache.hadoop.hbase.client.MetaScanner;
46 import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitor;
47 import org.apache.hadoop.hbase.client.Result;
48 import org.apache.hadoop.hbase.regionserver.HRegionFileSystem;
49 import org.apache.hadoop.hbase.util.Bytes;
50 import org.apache.hadoop.hbase.util.FSUtils;
51 import org.apache.hadoop.hbase.util.Pair;
52 import org.apache.hadoop.hbase.util.PairOfSameType;
53 import org.apache.hadoop.hbase.util.Threads;
54 import org.apache.hadoop.hbase.util.Triple;
55
56
57
58
59
60 @InterfaceAudience.Private
61 public class CatalogJanitor extends ScheduledChore {
62 private static final Log LOG = LogFactory.getLog(CatalogJanitor.class.getName());
63 private final Server server;
64 private final MasterServices services;
65 private AtomicBoolean enabled = new AtomicBoolean(true);
66 private AtomicBoolean alreadyRunning = new AtomicBoolean(false);
67 private final Connection connection;
68
69 CatalogJanitor(final Server server, final MasterServices services) {
70 super("CatalogJanitor-" + server.getServerName().toShortString(), server, server
71 .getConfiguration().getInt("hbase.catalogjanitor.interval", 300000));
72 this.server = server;
73 this.services = services;
74 this.connection = server.getConnection();
75 }
76
77 @Override
78 protected boolean initialChore() {
79 try {
80 if (this.enabled.get()) scan();
81 } catch (IOException e) {
82 LOG.warn("Failed initial scan of catalog table", e);
83 return false;
84 }
85 return true;
86 }
87
88
89
90
91 public boolean setEnabled(final boolean enabled) {
92 boolean alreadyEnabled = this.enabled.getAndSet(enabled);
93
94
95
96
97 if (!enabled && alreadyEnabled) {
98 while (alreadyRunning.get()) {
99 Threads.sleepWithoutInterrupt(100);
100 }
101 }
102 return alreadyEnabled;
103 }
104
105 boolean getEnabled() {
106 return this.enabled.get();
107 }
108
109 @Override
110 protected void chore() {
111 try {
112 AssignmentManager am = this.services.getAssignmentManager();
113 if (this.enabled.get()
114 && am != null
115 && am.isFailoverCleanupDone()
116 && am.getRegionStates().getRegionsInTransition().size() == 0) {
117 scan();
118 } else {
119 LOG.warn("CatalogJanitor disabled! Not running scan.");
120 }
121 } catch (IOException e) {
122 LOG.warn("Failed scan of catalog table", e);
123 }
124 }
125
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133 Triple<Integer, Map<HRegionInfo, Result>, Map<HRegionInfo, Result>> getMergedRegionsAndSplitParents()
134 throws IOException {
135 return getMergedRegionsAndSplitParents(null);
136 }
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148 Triple<Integer, Map<HRegionInfo, Result>, Map<HRegionInfo, Result>> getMergedRegionsAndSplitParents(
149 final TableName tableName) throws IOException {
150 final boolean isTableSpecified = (tableName != null);
151
152 final AtomicInteger count = new AtomicInteger(0);
153
154
155 final Map<HRegionInfo, Result> splitParents =
156 new TreeMap<HRegionInfo, Result>(new SplitParentFirstComparator());
157 final Map<HRegionInfo, Result> mergedRegions = new TreeMap<HRegionInfo, Result>();
158
159
160 MetaScannerVisitor visitor = new MetaScanner.MetaScannerVisitorBase() {
161 @Override
162 public boolean processRow(Result r) throws IOException {
163 if (r == null || r.isEmpty()) return true;
164 count.incrementAndGet();
165 HRegionInfo info = HRegionInfo.getHRegionInfo(r);
166 if (info == null) return true;
167 if (isTableSpecified
168 && info.getTable().compareTo(tableName) > 0) {
169
170 return false;
171 }
172 if (info.isSplitParent()) splitParents.put(info, r);
173 if (r.getValue(HConstants.CATALOG_FAMILY, HConstants.MERGEA_QUALIFIER) != null) {
174 mergedRegions.put(info, r);
175 }
176
177 return true;
178 }
179 };
180
181
182
183 MetaScanner.metaScan(this.connection, visitor, tableName);
184
185 return new Triple<Integer, Map<HRegionInfo, Result>, Map<HRegionInfo, Result>>(
186 count.get(), mergedRegions, splitParents);
187 }
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198
199 boolean cleanMergeRegion(final HRegionInfo mergedRegion,
200 final HRegionInfo regionA, final HRegionInfo regionB) throws IOException {
201 FileSystem fs = this.services.getMasterFileSystem().getFileSystem();
202 Path rootdir = this.services.getMasterFileSystem().getRootDir();
203 Path tabledir = FSUtils.getTableDir(rootdir, mergedRegion.getTable());
204 HTableDescriptor htd = getTableDescriptor(mergedRegion.getTable());
205 HRegionFileSystem regionFs = null;
206 try {
207 regionFs = HRegionFileSystem.openRegionFromFileSystem(
208 this.services.getConfiguration(), fs, tabledir, mergedRegion, true);
209 } catch (IOException e) {
210 LOG.warn("Merged region does not exist: " + mergedRegion.getEncodedName());
211 }
212 if (regionFs == null || !regionFs.hasReferences(htd)) {
213 LOG.debug("Deleting region " + regionA.getRegionNameAsString() + " and "
214 + regionB.getRegionNameAsString()
215 + " from fs because merged region no longer holds references");
216 HFileArchiver.archiveRegion(this.services.getConfiguration(), fs, regionA);
217 HFileArchiver.archiveRegion(this.services.getConfiguration(), fs, regionB);
218 MetaTableAccessor.deleteMergeQualifiers(services.getConnection(), mergedRegion);
219 services.getServerManager().removeRegion(regionA);
220 services.getServerManager().removeRegion(regionB);
221 return true;
222 }
223 return false;
224 }
225
226
227
228
229
230
231
232 int scan() throws IOException {
233 try {
234 if (!alreadyRunning.compareAndSet(false, true)) {
235 return 0;
236 }
237 Triple<Integer, Map<HRegionInfo, Result>, Map<HRegionInfo, Result>> scanTriple =
238 getMergedRegionsAndSplitParents();
239 int count = scanTriple.getFirst();
240
241
242
243 int mergeCleaned = 0;
244 Map<HRegionInfo, Result> mergedRegions = scanTriple.getSecond();
245 for (Map.Entry<HRegionInfo, Result> e : mergedRegions.entrySet()) {
246 HRegionInfo regionA = HRegionInfo.getHRegionInfo(e.getValue(),
247 HConstants.MERGEA_QUALIFIER);
248 HRegionInfo regionB = HRegionInfo.getHRegionInfo(e.getValue(),
249 HConstants.MERGEB_QUALIFIER);
250 if (regionA == null || regionB == null) {
251 LOG.warn("Unexpected references regionA="
252 + (regionA == null ? "null" : regionA.getRegionNameAsString())
253 + ",regionB="
254 + (regionB == null ? "null" : regionB.getRegionNameAsString())
255 + " in merged region " + e.getKey().getRegionNameAsString());
256 } else {
257 if (cleanMergeRegion(e.getKey(), regionA, regionB)) {
258 mergeCleaned++;
259 }
260 }
261 }
262
263
264
265 Map<HRegionInfo, Result> splitParents = scanTriple.getThird();
266
267
268 int splitCleaned = 0;
269
270 HashSet<String> parentNotCleaned = new HashSet<String>();
271 for (Map.Entry<HRegionInfo, Result> e : splitParents.entrySet()) {
272 if (!parentNotCleaned.contains(e.getKey().getEncodedName()) &&
273 cleanParent(e.getKey(), e.getValue())) {
274 splitCleaned++;
275 } else {
276
277 PairOfSameType<HRegionInfo> daughters = HRegionInfo.getDaughterRegions(e.getValue());
278 parentNotCleaned.add(daughters.getFirst().getEncodedName());
279 parentNotCleaned.add(daughters.getSecond().getEncodedName());
280 }
281 }
282 if ((mergeCleaned + splitCleaned) != 0) {
283 LOG.info("Scanned " + count + " catalog row(s), gc'd " + mergeCleaned
284 + " unreferenced merged region(s) and " + splitCleaned
285 + " unreferenced parent region(s)");
286 } else if (LOG.isTraceEnabled()) {
287 LOG.trace("Scanned " + count + " catalog row(s), gc'd " + mergeCleaned
288 + " unreferenced merged region(s) and " + splitCleaned
289 + " unreferenced parent region(s)");
290 }
291 return mergeCleaned + splitCleaned;
292 } finally {
293 alreadyRunning.set(false);
294 }
295 }
296
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298
299
300
301 static class SplitParentFirstComparator implements Comparator<HRegionInfo> {
302 Comparator<byte[]> rowEndKeyComparator = new Bytes.RowEndKeyComparator();
303 @Override
304 public int compare(HRegionInfo left, HRegionInfo right) {
305
306
307 if (left == null) return -1;
308 if (right == null) return 1;
309
310 int result = left.getTable().compareTo(right.getTable());
311 if (result != 0) return result;
312
313 result = Bytes.compareTo(left.getStartKey(), right.getStartKey());
314 if (result != 0) return result;
315
316 result = rowEndKeyComparator.compare(right.getEndKey(), left.getEndKey());
317
318 return result;
319 }
320 }
321
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329
330
331 boolean cleanParent(final HRegionInfo parent, Result rowContent)
332 throws IOException {
333 boolean result = false;
334
335
336
337 if (rowContent.getValue(HConstants.CATALOG_FAMILY,
338 HConstants.MERGEA_QUALIFIER) != null) {
339
340 return result;
341 }
342
343 PairOfSameType<HRegionInfo> daughters = HRegionInfo.getDaughterRegions(rowContent);
344 Pair<Boolean, Boolean> a = checkDaughterInFs(parent, daughters.getFirst());
345 Pair<Boolean, Boolean> b = checkDaughterInFs(parent, daughters.getSecond());
346 if (hasNoReferences(a) && hasNoReferences(b)) {
347 LOG.debug("Deleting region " + parent.getRegionNameAsString() +
348 " because daughter splits no longer hold references");
349 FileSystem fs = this.services.getMasterFileSystem().getFileSystem();
350 if (LOG.isTraceEnabled()) LOG.trace("Archiving parent region: " + parent);
351 HFileArchiver.archiveRegion(this.services.getConfiguration(), fs, parent);
352 MetaTableAccessor.deleteRegion(this.connection, parent);
353 services.getServerManager().removeRegion(parent);
354 result = true;
355 }
356 return result;
357 }
358
359
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363
364
365 private boolean hasNoReferences(final Pair<Boolean, Boolean> p) {
366 return !p.getFirst() || !p.getSecond();
367 }
368
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378
379 Pair<Boolean, Boolean> checkDaughterInFs(final HRegionInfo parent, final HRegionInfo daughter)
380 throws IOException {
381 if (daughter == null) {
382 return new Pair<Boolean, Boolean>(Boolean.FALSE, Boolean.FALSE);
383 }
384
385 FileSystem fs = this.services.getMasterFileSystem().getFileSystem();
386 Path rootdir = this.services.getMasterFileSystem().getRootDir();
387 Path tabledir = FSUtils.getTableDir(rootdir, daughter.getTable());
388
389 Path daughterRegionDir = new Path(tabledir, daughter.getEncodedName());
390
391 HRegionFileSystem regionFs = null;
392
393 try {
394 if (!FSUtils.isExists(fs, daughterRegionDir)) {
395 return new Pair<Boolean, Boolean>(Boolean.FALSE, Boolean.FALSE);
396 }
397 } catch (IOException ioe) {
398 LOG.error("Error trying to determine if daughter region exists, " +
399 "assuming exists and has references", ioe);
400 return new Pair<Boolean, Boolean>(Boolean.TRUE, Boolean.TRUE);
401 }
402
403 boolean references = false;
404 HTableDescriptor parentDescriptor = getTableDescriptor(parent.getTable());
405 try {
406 regionFs = HRegionFileSystem.openRegionFromFileSystem(
407 this.services.getConfiguration(), fs, tabledir, daughter, true);
408
409 for (HColumnDescriptor family: parentDescriptor.getFamilies()) {
410 if ((references = regionFs.hasReferences(family.getNameAsString()))) {
411 break;
412 }
413 }
414 } catch (IOException e) {
415 LOG.error("Error trying to determine referenced files from : " + daughter.getEncodedName()
416 + ", to: " + parent.getEncodedName() + " assuming has references", e);
417 return new Pair<Boolean, Boolean>(Boolean.TRUE, Boolean.TRUE);
418 }
419 return new Pair<Boolean, Boolean>(Boolean.TRUE, Boolean.valueOf(references));
420 }
421
422 private HTableDescriptor getTableDescriptor(final TableName tableName)
423 throws FileNotFoundException, IOException {
424 return this.services.getTableDescriptors().get(tableName);
425 }
426
427
428
429
430
431
432
433
434 public boolean cleanMergeQualifier(final HRegionInfo region)
435 throws IOException {
436
437
438 Pair<HRegionInfo, HRegionInfo> mergeRegions = MetaTableAccessor
439 .getRegionsFromMergeQualifier(this.services.getConnection(),
440 region.getRegionName());
441 if (mergeRegions == null
442 || (mergeRegions.getFirst() == null && mergeRegions.getSecond() == null)) {
443
444 return true;
445 }
446
447 if (mergeRegions.getFirst() == null || mergeRegions.getSecond() == null) {
448 LOG.error("Merged region " + region.getRegionNameAsString()
449 + " has only one merge qualifier in META.");
450 return false;
451 }
452 return cleanMergeRegion(region, mergeRegions.getFirst(),
453 mergeRegions.getSecond());
454 }
455 }