001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.master.hbck;
019
020import java.io.IOException;
021import java.time.Instant;
022import java.util.HashMap;
023import java.util.HashSet;
024import java.util.LinkedList;
025import java.util.List;
026import java.util.Map;
027import java.util.Set;
028import org.apache.hadoop.fs.FileSystem;
029import org.apache.hadoop.fs.Path;
030import org.apache.hadoop.hbase.CatalogFamilyFormat;
031import org.apache.hadoop.hbase.MetaTableAccessor;
032import org.apache.hadoop.hbase.ScheduledChore;
033import org.apache.hadoop.hbase.ServerName;
034import org.apache.hadoop.hbase.client.RegionInfo;
035import org.apache.hadoop.hbase.client.TableState;
036import org.apache.hadoop.hbase.master.MasterServices;
037import org.apache.hadoop.hbase.master.RegionState;
038import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
039import org.apache.hadoop.hbase.util.FSUtils;
040import org.apache.hadoop.hbase.util.HbckRegionInfo;
041import org.apache.hadoop.hbase.util.Pair;
042import org.apache.yetus.audience.InterfaceAudience;
043import org.apache.yetus.audience.InterfaceStability;
044import org.slf4j.Logger;
045import org.slf4j.LoggerFactory;
046
047/**
048 * Used to do the hbck checking job at master side.
049 */
050@InterfaceAudience.Private
051@InterfaceStability.Evolving
052public class HbckChore extends ScheduledChore {
053  private static final Logger LOG = LoggerFactory.getLogger(HbckChore.class.getName());
054
055  private static final String HBCK_CHORE_INTERVAL = "hbase.master.hbck.chore.interval";
056  private static final int DEFAULT_HBCK_CHORE_INTERVAL = 60 * 60 * 1000;
057
058  private final MasterServices master;
059
060  /**
061   * Saved report from last time this chore ran. Check its date.
062   */
063  private volatile HbckReport lastReport = null;
064
065  /**
066   * When running, the "snapshot" may be changed when this round's checking finish.
067   */
068  private volatile boolean running = false;
069
070  private boolean disabled = false;
071
072  public HbckChore(MasterServices master) {
073    super("HbckChore-", master,
074      master.getConfiguration().getInt(HBCK_CHORE_INTERVAL, DEFAULT_HBCK_CHORE_INTERVAL));
075    this.master = master;
076    int interval =
077      master.getConfiguration().getInt(HBCK_CHORE_INTERVAL, DEFAULT_HBCK_CHORE_INTERVAL);
078    if (interval <= 0) {
079      LOG.warn(HBCK_CHORE_INTERVAL + " is <=0 hence disabling hbck chore");
080      disableChore();
081    }
082  }
083
084  /**
085   * Returns Returns last published Report that comes of last successful execution of this chore.
086   */
087  public HbckReport getLastReport() {
088    return lastReport;
089  }
090
091  @Override
092  protected synchronized void chore() {
093    if (isDisabled() || isRunning()) {
094      LOG.warn("hbckChore is either disabled or is already running. Can't run the chore");
095      return;
096    }
097    running = true;
098    final HbckReport report = new HbckReport();
099    report.setCheckingStartTimestamp(Instant.ofEpochMilli(EnvironmentEdgeManager.currentTime()));
100    try {
101      loadRegionsFromInMemoryState(report);
102      loadRegionsFromRSReport(report);
103      try {
104        loadRegionsFromFS(scanForMergedParentRegions(), report);
105      } catch (IOException e) {
106        LOG.warn("Failed to load the regions from filesystem", e);
107      }
108    } catch (Throwable t) {
109      LOG.warn("Unexpected", t);
110    }
111    report.setCheckingEndTimestamp(Instant.ofEpochMilli(EnvironmentEdgeManager.currentTime()));
112    this.lastReport = report;
113    running = false;
114    updateAssignmentManagerMetrics(report);
115  }
116
117  /**
118   * Request execution of this chore's action.
119   * @return {@code true} if the chore was executed, {@code false} if the chore is disabled or
120   *         already running.
121   */
122  public boolean runChore() {
123    // This function does the sanity checks of making sure the chore is not run when it is
124    // disabled or when it's already running. It returns whether the chore was actually run or not.
125    if (isDisabled() || isRunning()) {
126      if (isDisabled()) {
127        LOG.warn("hbck chore is disabled! Set " + HBCK_CHORE_INTERVAL + " > 0 to enable it.");
128      } else {
129        LOG.warn("hbck chore already running. Can't run till it finishes.");
130      }
131      return false;
132    }
133    chore();
134    return true;
135  }
136
137  private void disableChore() {
138    this.disabled = true;
139  }
140
141  public boolean isDisabled() {
142    return this.disabled;
143  }
144
145  /**
146   * Scan hbase:meta to get set of merged parent regions, this is a very heavy scan.
147   * @return Return generated {@link HashSet}
148   */
149  private HashSet<String> scanForMergedParentRegions() throws IOException {
150    HashSet<String> mergedParentRegions = new HashSet<>();
151    // Null tablename means scan all of meta.
152    MetaTableAccessor.scanMetaForTableRegions(this.master.getConnection(), r -> {
153      List<RegionInfo> mergeParents = CatalogFamilyFormat.getMergeRegions(r.rawCells());
154      if (mergeParents != null) {
155        for (RegionInfo mergeRegion : mergeParents) {
156          if (mergeRegion != null) {
157            // This region is already being merged
158            mergedParentRegions.add(mergeRegion.getEncodedName());
159          }
160        }
161      }
162      return true;
163    }, null);
164    return mergedParentRegions;
165  }
166
167  private void loadRegionsFromInMemoryState(final HbckReport report) {
168    List<RegionState> regionStates =
169      master.getAssignmentManager().getRegionStates().getRegionStates();
170    for (RegionState regionState : regionStates) {
171      RegionInfo regionInfo = regionState.getRegion();
172      if (
173        master.getTableStateManager().isTableState(regionInfo.getTable(), TableState.State.DISABLED)
174      ) {
175        report.getDisabledTableRegions().add(regionInfo.getRegionNameAsString());
176      }
177      // Check both state and regioninfo for split status, see HBASE-26383
178      if (regionState.isSplit() || regionInfo.isSplit()) {
179        report.getSplitParentRegions().add(regionInfo.getRegionNameAsString());
180      }
181      HbckRegionInfo.MetaEntry metaEntry = new HbckRegionInfo.MetaEntry(regionInfo,
182        regionState.getServerName(), regionState.getStamp());
183      report.getRegionInfoMap().put(regionInfo.getEncodedName(), new HbckRegionInfo(metaEntry));
184    }
185    LOG.info("Loaded {} regions ({} disabled, {} split parents) from in-memory state",
186      regionStates.size(), report.getDisabledTableRegions().size(),
187      report.getSplitParentRegions().size());
188    if (LOG.isDebugEnabled()) {
189      Map<RegionState.State, Integer> stateCountMap = new HashMap<>();
190      for (RegionState regionState : regionStates) {
191        stateCountMap.compute(regionState.getState(), (k, v) -> (v == null) ? 1 : v + 1);
192      }
193      StringBuffer sb = new StringBuffer();
194      sb.append("Regions by state: ");
195      stateCountMap.entrySet().forEach(e -> {
196        sb.append(e.getKey());
197        sb.append('=');
198        sb.append(e.getValue());
199        sb.append(' ');
200      });
201      LOG.debug(sb.toString());
202    }
203    if (LOG.isTraceEnabled()) {
204      for (RegionState regionState : regionStates) {
205        LOG.trace("{}: {}, serverName={}", regionState.getRegion(), regionState.getState(),
206          regionState.getServerName());
207      }
208    }
209  }
210
211  private void loadRegionsFromRSReport(final HbckReport report) {
212    int numRegions = 0;
213    Map<ServerName, Set<byte[]>> rsReports = master.getAssignmentManager().getRSReports();
214    for (Map.Entry<ServerName, Set<byte[]>> entry : rsReports.entrySet()) {
215      ServerName serverName = entry.getKey();
216      for (byte[] regionName : entry.getValue()) {
217        String encodedRegionName = RegionInfo.encodeRegionName(regionName);
218        HbckRegionInfo hri = report.getRegionInfoMap().get(encodedRegionName);
219        if (hri == null) {
220          report.getOrphanRegionsOnRS().put(RegionInfo.getRegionNameAsString(regionName),
221            serverName);
222          continue;
223        }
224        hri.addServer(hri.getMetaEntry().getRegionInfo(), serverName);
225      }
226      numRegions += entry.getValue().size();
227    }
228    LOG.info("Loaded {} regions from {} regionservers' reports and found {} orphan regions",
229      numRegions, rsReports.size(), report.getOrphanRegionsOnRS().size());
230
231    for (Map.Entry<String, HbckRegionInfo> entry : report.getRegionInfoMap().entrySet()) {
232      HbckRegionInfo hri = entry.getValue();
233      ServerName locationInMeta = hri.getMetaEntry().getRegionServer(); // can be null
234      if (hri.getDeployedOn().size() == 0) {
235        // skip the offline region which belong to disabled table.
236        if (report.getDisabledTableRegions().contains(hri.getRegionNameAsString())) {
237          continue;
238        }
239        // skip the split parent regions
240        if (report.getSplitParentRegions().contains(hri.getRegionNameAsString())) {
241          continue;
242        }
243        // Master thought this region opened, but no regionserver reported it.
244        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
245          new Pair<>(locationInMeta, new LinkedList<>()));
246      } else if (hri.getDeployedOn().size() > 1) {
247        // More than one regionserver reported opened this region
248        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
249          new Pair<>(locationInMeta, hri.getDeployedOn()));
250      } else if (!hri.getDeployedOn().get(0).equals(locationInMeta)) {
251        // Master thought this region opened on Server1, but regionserver reported Server2
252        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
253          new Pair<>(locationInMeta, hri.getDeployedOn()));
254      }
255    }
256  }
257
258  private void loadRegionsFromFS(final HashSet<String> mergedParentRegions, final HbckReport report)
259    throws IOException {
260    Path rootDir = master.getMasterFileSystem().getRootDir();
261    FileSystem fs = master.getMasterFileSystem().getFileSystem();
262
263    int numRegions = 0;
264    List<Path> tableDirs = FSUtils.getTableDirs(fs, rootDir);
265    for (Path tableDir : tableDirs) {
266      List<Path> regionDirs = FSUtils.getRegionDirs(fs, tableDir);
267      for (Path regionDir : regionDirs) {
268        String encodedRegionName = regionDir.getName();
269        if (encodedRegionName == null) {
270          LOG.warn("Failed get of encoded name from {}", regionDir);
271          continue;
272        }
273        HbckRegionInfo hri = report.getRegionInfoMap().get(encodedRegionName);
274        // If it is not in in-memory database and not a merged region,
275        // report it as an orphan region.
276        if (hri == null && !mergedParentRegions.contains(encodedRegionName)) {
277          report.getOrphanRegionsOnFS().put(encodedRegionName, regionDir);
278          continue;
279        }
280      }
281      numRegions += regionDirs.size();
282    }
283    LOG.info("Loaded {} tables {} regions from filesystem and found {} orphan regions",
284      tableDirs.size(), numRegions, report.getOrphanRegionsOnFS().size());
285  }
286
287  private void updateAssignmentManagerMetrics(final HbckReport report) {
288    master.getAssignmentManager().getAssignmentManagerMetrics()
289      .updateOrphanRegionsOnRs(report.getOrphanRegionsOnRS().size());
290    master.getAssignmentManager().getAssignmentManagerMetrics()
291      .updateOrphanRegionsOnFs(report.getOrphanRegionsOnFS().size());
292    master.getAssignmentManager().getAssignmentManagerMetrics()
293      .updateInconsistentRegions(report.getInconsistentRegions().size());
294  }
295
296  /**
297   * When running, the HBCK report may be changed later.
298   */
299  public boolean isRunning() {
300    return running;
301  }
302}