HBASE-27095 HbckChore should produce a report

In #4470 for HBASE-26192, it was noted that the HbckChore is kind of a pain to use and test
because it maintains a bunch of local state. By contract, the CatalogJanitorChore makes a nice
self-contained report. Let's update HbckChore to do the same.

Signed-off-by: Andrew Purtell <apurtell@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -130,6 +130,7 @@ import org.apache.hadoop.hbase.master.cleaner.HFileCleaner;
 import org.apache.hadoop.hbase.master.cleaner.LogCleaner;
 import org.apache.hadoop.hbase.master.cleaner.ReplicationBarrierCleaner;
 import org.apache.hadoop.hbase.master.cleaner.SnapshotCleanerChore;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
 import org.apache.hadoop.hbase.master.http.MasterDumpServlet;
 import org.apache.hadoop.hbase.master.http.MasterRedirectServlet;
 import org.apache.hadoop.hbase.master.http.MasterStatusServlet;

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java

@@ -75,6 +75,7 @@ import org.apache.hadoop.hbase.ipc.ServerRpcController;
 import org.apache.hadoop.hbase.master.assignment.RegionStateNode;
 import org.apache.hadoop.hbase.master.assignment.RegionStates;
 import org.apache.hadoop.hbase.master.cleaner.HFileCleaner;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
 import org.apache.hadoop.hbase.master.janitor.MetaFixer;
 import org.apache.hadoop.hbase.master.locking.LockProcedure;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;

hbase-server/src/main/java/org/apache/hadoop/hbase/master/hbck/HbckChore.java

@@ -15,16 +15,16 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.hbase.master;
+package org.apache.hadoop.hbase.master.hbck;
 
 import java.io.IOException;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.MetaTableAccessor;
@@ -32,6 +32,8 @@ import org.apache.hadoop.hbase.ScheduledChore;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.TableState;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.master.RegionState;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.HbckRegionInfo;
@@ -55,51 +57,14 @@ public class HbckChore extends ScheduledChore {
   private final MasterServices master;
 
   /**
-   * This map contains the state of all hbck items. It maps from encoded region name to
+   * Saved report from last time this chore ran. Check its date.
-   * HbckRegionInfo structure. The information contained in HbckRegionInfo is used to detect and
-   * correct consistency (hdfs/meta/deployment) problems.
    */
-  private final Map<String, HbckRegionInfo> regionInfoMap = new HashMap<>();
+  private volatile HbckReport lastReport = null;
-
-  private final Set<String> disabledTableRegions = new HashSet<>();
-  private final Set<String> splitParentRegions = new HashSet<>();
-
-  /**
-   * The regions only opened on RegionServers, but no region info in meta.
-   */
-  private final Map<String, ServerName> orphanRegionsOnRS = new HashMap<>();
-  /**
-   * The regions have directory on FileSystem, but no region info in meta.
-   */
-  private final Map<String, Path> orphanRegionsOnFS = new HashMap<>();
-  /**
-   * The inconsistent regions. There are three case: case 1. Master thought this region opened, but
-   * no regionserver reported it. case 2. Master thought this region opened on Server1, but
-   * regionserver reported Server2 case 3. More than one regionservers reported opened this region
-   */
-  private final Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
-    new HashMap<>();
-
-  /**
-   * The "snapshot" is used to save the last round's HBCK checking report.
-   */
-  private final Map<String, ServerName> orphanRegionsOnRSSnapshot = new HashMap<>();
-  private final Map<String, Path> orphanRegionsOnFSSnapshot = new HashMap<>();
-  private final Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegionsSnapshot =
-    new HashMap<>();
-
-  /**
-   * The "snapshot" may be changed after checking. And this checking report "snapshot" may be
-   * accessed by web ui. Use this rwLock to synchronize.
-   */
-  ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
 
   /**
    * When running, the "snapshot" may be changed when this round's checking finish.
    */
   private volatile boolean running = false;
-  private volatile long checkingStartTimestamp = 0;
-  private volatile long checkingEndTimestamp = 0;
 
   private boolean disabled = false;
 
@@ -115,39 +80,47 @@ public class HbckChore extends ScheduledChore {
     }
   }
 
+  /**
+   * @return Returns last published Report that comes of last successful execution of this chore.
+   */
+  public HbckReport getLastReport() {
+    return lastReport;
+  }
+
   @Override
   protected synchronized void chore() {
     if (isDisabled() || isRunning()) {
       LOG.warn("hbckChore is either disabled or is already running. Can't run the chore");
       return;
     }
-    regionInfoMap.clear();
-    disabledTableRegions.clear();
-    splitParentRegions.clear();
-    orphanRegionsOnRS.clear();
-    orphanRegionsOnFS.clear();
-    inconsistentRegions.clear();
-    checkingStartTimestamp = EnvironmentEdgeManager.currentTime();
     running = true;
+    final HbckReport report = new HbckReport();
+    report.setCheckingStartTimestamp(Instant.ofEpochMilli(EnvironmentEdgeManager.currentTime()));
     try {
-      loadRegionsFromInMemoryState();
+      loadRegionsFromInMemoryState(report);
-      loadRegionsFromRSReport();
+      loadRegionsFromRSReport(report);
       try {
-        loadRegionsFromFS(scanForMergedParentRegions());
+        loadRegionsFromFS(scanForMergedParentRegions(), report);
       } catch (IOException e) {
         LOG.warn("Failed to load the regions from filesystem", e);
       }
-      saveCheckResultToSnapshot();
     } catch (Throwable t) {
       LOG.warn("Unexpected", t);
     }
+    report.setCheckingEndTimestamp(Instant.ofEpochMilli(EnvironmentEdgeManager.currentTime()));
+    this.lastReport = report;
     running = false;
-    updateAssignmentManagerMetrics();
+    updateAssignmentManagerMetrics(report);
   }
 
+  /**
+   * Request execution of this chore's action.
+   * @return {@code true} if the chore was executed, {@code false} if the chore is disabled or
+   *         already running.
+   */
+  public boolean runChore() {
     // This function does the sanity checks of making sure the chore is not run when it is
     // disabled or when it's already running. It returns whether the chore was actually run or not.
-  protected boolean runChore() {
     if (isDisabled() || isRunning()) {
       if (isDisabled()) {
         LOG.warn("hbck chore is disabled! Set " + HBCK_CHORE_INTERVAL + " > 0 to enable it.");
@@ -168,25 +141,6 @@ public class HbckChore extends ScheduledChore {
     return this.disabled;
   }
 
-  private void saveCheckResultToSnapshot() {
-    // Need synchronized here, as this "snapshot" may be access by web ui.
-    rwLock.writeLock().lock();
-    try {
-      orphanRegionsOnRSSnapshot.clear();
-      orphanRegionsOnRS.entrySet()
-        .forEach(e -> orphanRegionsOnRSSnapshot.put(e.getKey(), e.getValue()));
-      orphanRegionsOnFSSnapshot.clear();
-      orphanRegionsOnFS.entrySet()
-        .forEach(e -> orphanRegionsOnFSSnapshot.put(e.getKey(), e.getValue()));
-      inconsistentRegionsSnapshot.clear();
-      inconsistentRegions.entrySet()
-        .forEach(e -> inconsistentRegionsSnapshot.put(e.getKey(), e.getValue()));
-      checkingEndTimestamp = EnvironmentEdgeManager.currentTime();
-    } finally {
-      rwLock.writeLock().unlock();
-    }
-  }
-
   /**
    * Scan hbase:meta to get set of merged parent regions, this is a very heavy scan.
    * @return Return generated {@link HashSet}
@@ -209,7 +163,7 @@ public class HbckChore extends ScheduledChore {
     return mergedParentRegions;
   }
 
-  private void loadRegionsFromInMemoryState() {
+  private void loadRegionsFromInMemoryState(final HbckReport report) {
     List<RegionState> regionStates =
       master.getAssignmentManager().getRegionStates().getRegionStates();
     for (RegionState regionState : regionStates) {
@@ -217,18 +171,19 @@ public class HbckChore extends ScheduledChore {
       if (
         master.getTableStateManager().isTableState(regionInfo.getTable(), TableState.State.DISABLED)
       ) {
-        disabledTableRegions.add(regionInfo.getRegionNameAsString());
+        report.getDisabledTableRegions().add(regionInfo.getRegionNameAsString());
       }
       // Check both state and regioninfo for split status, see HBASE-26383
       if (regionState.isSplit() || regionInfo.isSplit()) {
-        splitParentRegions.add(regionInfo.getRegionNameAsString());
+        report.getSplitParentRegions().add(regionInfo.getRegionNameAsString());
       }
       HbckRegionInfo.MetaEntry metaEntry = new HbckRegionInfo.MetaEntry(regionInfo,
         regionState.getServerName(), regionState.getStamp());
-      regionInfoMap.put(regionInfo.getEncodedName(), new HbckRegionInfo(metaEntry));
+      report.getRegionInfoMap().put(regionInfo.getEncodedName(), new HbckRegionInfo(metaEntry));
     }
     LOG.info("Loaded {} regions ({} disabled, {} split parents) from in-memory state",
-      regionStates.size(), disabledTableRegions.size(), splitParentRegions.size());
+      regionStates.size(), report.getDisabledTableRegions().size(),
+      report.getSplitParentRegions().size());
     if (LOG.isDebugEnabled()) {
       Map<RegionState.State, Integer> stateCountMap = new HashMap<>();
       for (RegionState regionState : regionStates) {
@@ -246,22 +201,23 @@ public class HbckChore extends ScheduledChore {
     }
     if (LOG.isTraceEnabled()) {
       for (RegionState regionState : regionStates) {
-        LOG.trace("{}: {}, serverName=", regionState.getRegion(), regionState.getState(),
+        LOG.trace("{}: {}, serverName={}", regionState.getRegion(), regionState.getState(),
           regionState.getServerName());
       }
     }
   }
 
-  private void loadRegionsFromRSReport() {
+  private void loadRegionsFromRSReport(final HbckReport report) {
     int numRegions = 0;
     Map<ServerName, Set<byte[]>> rsReports = master.getAssignmentManager().getRSReports();
     for (Map.Entry<ServerName, Set<byte[]>> entry : rsReports.entrySet()) {
       ServerName serverName = entry.getKey();
       for (byte[] regionName : entry.getValue()) {
         String encodedRegionName = RegionInfo.encodeRegionName(regionName);
-        HbckRegionInfo hri = regionInfoMap.get(encodedRegionName);
+        HbckRegionInfo hri = report.getRegionInfoMap().get(encodedRegionName);
         if (hri == null) {
-          orphanRegionsOnRS.put(RegionInfo.getRegionNameAsString(regionName), serverName);
+          report.getOrphanRegionsOnRS().put(RegionInfo.getRegionNameAsString(regionName),
+            serverName);
           continue;
         }
         hri.addServer(hri.getMetaEntry(), serverName);
@@ -269,9 +225,9 @@ public class HbckChore extends ScheduledChore {
       numRegions += entry.getValue().size();
     }
     LOG.info("Loaded {} regions from {} regionservers' reports and found {} orphan regions",
-      numRegions, rsReports.size(), orphanRegionsOnRS.size());
+      numRegions, rsReports.size(), report.getOrphanRegionsOnRS().size());
 
-    for (Map.Entry<String, HbckRegionInfo> entry : regionInfoMap.entrySet()) {
+    for (Map.Entry<String, HbckRegionInfo> entry : report.getRegionInfoMap().entrySet()) {
       HbckRegionInfo hri = entry.getValue();
       ServerName locationInMeta = hri.getMetaEntry().getRegionServer();
       if (locationInMeta == null) {
@@ -279,29 +235,30 @@ public class HbckChore extends ScheduledChore {
       }
       if (hri.getDeployedOn().size() == 0) {
         // skip the offline region which belong to disabled table.
-        if (disabledTableRegions.contains(hri.getRegionNameAsString())) {
+        if (report.getDisabledTableRegions().contains(hri.getRegionNameAsString())) {
           continue;
         }
         // skip the split parent regions
-        if (splitParentRegions.contains(hri.getRegionNameAsString())) {
+        if (report.getSplitParentRegions().contains(hri.getRegionNameAsString())) {
           continue;
         }
         // Master thought this region opened, but no regionserver reported it.
-        inconsistentRegions.put(hri.getRegionNameAsString(),
+        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
           new Pair<>(locationInMeta, new LinkedList<>()));
       } else if (hri.getDeployedOn().size() > 1) {
         // More than one regionserver reported opened this region
-        inconsistentRegions.put(hri.getRegionNameAsString(),
+        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
           new Pair<>(locationInMeta, hri.getDeployedOn()));
       } else if (!hri.getDeployedOn().get(0).equals(locationInMeta)) {
         // Master thought this region opened on Server1, but regionserver reported Server2
-        inconsistentRegions.put(hri.getRegionNameAsString(),
+        report.getInconsistentRegions().put(hri.getRegionNameAsString(),
           new Pair<>(locationInMeta, hri.getDeployedOn()));
       }
     }
   }
 
-  private void loadRegionsFromFS(final HashSet<String> mergedParentRegions) throws IOException {
+  private void loadRegionsFromFS(final HashSet<String> mergedParentRegions, final HbckReport report)
+    throws IOException {
     Path rootDir = master.getMasterFileSystem().getRootDir();
     FileSystem fs = master.getMasterFileSystem().getFileSystem();
 
@@ -315,27 +272,27 @@ public class HbckChore extends ScheduledChore {
           LOG.warn("Failed get of encoded name from {}", regionDir);
           continue;
         }
-        HbckRegionInfo hri = regionInfoMap.get(encodedRegionName);
+        HbckRegionInfo hri = report.getRegionInfoMap().get(encodedRegionName);
         // If it is not in in-memory database and not a merged region,
         // report it as an orphan region.
         if (hri == null && !mergedParentRegions.contains(encodedRegionName)) {
-          orphanRegionsOnFS.put(encodedRegionName, regionDir);
+          report.getOrphanRegionsOnFS().put(encodedRegionName, regionDir);
           continue;
         }
       }
       numRegions += regionDirs.size();
     }
     LOG.info("Loaded {} tables {} regions from filesystem and found {} orphan regions",
-      tableDirs.size(), numRegions, orphanRegionsOnFS.size());
+      tableDirs.size(), numRegions, report.getOrphanRegionsOnFS().size());
   }
 
-  private void updateAssignmentManagerMetrics() {
+  private void updateAssignmentManagerMetrics(final HbckReport report) {
     master.getAssignmentManager().getAssignmentManagerMetrics()
-      .updateOrphanRegionsOnRs(getOrphanRegionsOnRS().size());
+      .updateOrphanRegionsOnRs(report.getOrphanRegionsOnRS().size());
     master.getAssignmentManager().getAssignmentManagerMetrics()
-      .updateOrphanRegionsOnFs(getOrphanRegionsOnFS().size());
+      .updateOrphanRegionsOnFs(report.getOrphanRegionsOnFS().size());
     master.getAssignmentManager().getAssignmentManagerMetrics()
-      .updateInconsistentRegions(getInconsistentRegions().size());
+      .updateInconsistentRegions(report.getInconsistentRegions().size());
   }
 
   /**
@@ -344,62 +301,4 @@ public class HbckChore extends ScheduledChore {
   public boolean isRunning() {
     return running;
   }
-
-  /**
-   * @return the regions only opened on RegionServers, but no region info in meta.
-   */
-  public Map<String, ServerName> getOrphanRegionsOnRS() {
-    // Need synchronized here, as this "snapshot" may be changed after checking.
-    rwLock.readLock().lock();
-    try {
-      return this.orphanRegionsOnRSSnapshot;
-    } finally {
-      rwLock.readLock().unlock();
-    }
-  }
-
-  /**
-   * @return the regions have directory on FileSystem, but no region info in meta.
-   */
-  public Map<String, Path> getOrphanRegionsOnFS() {
-    // Need synchronized here, as this "snapshot" may be changed after checking.
-    rwLock.readLock().lock();
-    try {
-      return this.orphanRegionsOnFSSnapshot;
-    } finally {
-      rwLock.readLock().unlock();
-    }
-  }
-
-  /**
-   * Found the inconsistent regions. There are three case: case 1. Master thought this region
-   * opened, but no regionserver reported it. case 2. Master thought this region opened on Server1,
-   * but regionserver reported Server2 case 3. More than one regionservers reported opened this
-   * region
-   * @return the map of inconsistent regions. Key is the region name. Value is a pair of location in
-   *         meta and the regionservers which reported opened this region.
-   */
-  public Map<String, Pair<ServerName, List<ServerName>>> getInconsistentRegions() {
-    // Need synchronized here, as this "snapshot" may be changed after checking.
-    rwLock.readLock().lock();
-    try {
-      return this.inconsistentRegionsSnapshot;
-    } finally {
-      rwLock.readLock().unlock();
-    }
-  }
-
-  /**
-   * Used for web ui to show when the HBCK checking started.
-   */
-  public long getCheckingStartTimestamp() {
-    return this.checkingStartTimestamp;
-  }
-
-  /**
-   * Used for web ui to show when the HBCK checking report generated.
-   */
-  public long getCheckingEndTimestamp() {
-    return this.checkingEndTimestamp;
-  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/hbck/HbckReport.java

@@ -0,0 +1,110 @@
+/*
+ * 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.master.hbck;
+
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.util.HbckRegionInfo;
+import org.apache.hadoop.hbase.util.Pair;
+import org.apache.yetus.audience.InterfaceAudience;
+
+/**
+ * The result of an {@link HbckChore} execution.
+ */
+@InterfaceAudience.Private
+public class HbckReport {
+
+  private final Map<String, HbckRegionInfo> regionInfoMap = new HashMap<>();
+  private final Set<String> disabledTableRegions = new HashSet<>();
+  private final Set<String> splitParentRegions = new HashSet<>();
+  private final Map<String, ServerName> orphanRegionsOnRS = new HashMap<>();
+  private final Map<String, Path> orphanRegionsOnFS = new HashMap<>();
+  private final Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
+    new HashMap<>();
+
+  private Instant checkingStartTimestamp = null;
+  private Instant checkingEndTimestamp = null;
+
+  /**
+   * Used for web ui to show when the HBCK checking started.
+   */
+  public Instant getCheckingStartTimestamp() {
+    return checkingStartTimestamp;
+  }
+
+  public void setCheckingStartTimestamp(Instant checkingStartTimestamp) {
+    this.checkingStartTimestamp = checkingStartTimestamp;
+  }
+
+  /**
+   * Used for web ui to show when the HBCK checking report generated.
+   */
+  public Instant getCheckingEndTimestamp() {
+    return checkingEndTimestamp;
+  }
+
+  public void setCheckingEndTimestamp(Instant checkingEndTimestamp) {
+    this.checkingEndTimestamp = checkingEndTimestamp;
+  }
+
+  /**
+   * This map contains the state of all hbck items. It maps from encoded region name to
+   * HbckRegionInfo structure. The information contained in HbckRegionInfo is used to detect and
+   * correct consistency (hdfs/meta/deployment) problems.
+   */
+  public Map<String, HbckRegionInfo> getRegionInfoMap() {
+    return regionInfoMap;
+  }
+
+  public Set<String> getDisabledTableRegions() {
+    return disabledTableRegions;
+  }
+
+  public Set<String> getSplitParentRegions() {
+    return splitParentRegions;
+  }
+
+  /**
+   * The regions only opened on RegionServers, but no region info in meta.
+   */
+  public Map<String, ServerName> getOrphanRegionsOnRS() {
+    return orphanRegionsOnRS;
+  }
+
+  /**
+   * The regions have directory on FileSystem, but no region info in meta.
+   */
+  public Map<String, Path> getOrphanRegionsOnFS() {
+    return orphanRegionsOnFS;
+  }
+
+  /**
+   * The inconsistent regions. There are three case: case 1. Master thought this region opened, but
+   * no regionserver reported it. case 2. Master thought this region opened on Server1, but
+   * regionserver reported Server2 case 3. More than one regionservers reported opened this region
+   */
+  public Map<String, Pair<ServerName, List<ServerName>>> getInconsistentRegions() {
+    return inconsistentRegions;
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java

@@ -85,7 +85,7 @@ public class CatalogJanitor extends ScheduledChore {
    * Saved report from last hbase:meta scan to completion. May be stale if having trouble completing
    * scan. Check its date.
    */
-  private volatile Report lastReport;
+  private volatile CatalogJanitorReport lastReport;
 
   public CatalogJanitor(final MasterServices services) {
     super("CatalogJanitor-" + services.getServerName().toShortString(), services,
@@ -227,10 +227,10 @@ public class CatalogJanitor extends ScheduledChore {
 
   /**
    * Scan hbase:meta.
-   * @return Return generated {@link Report}
+   * @return Return generated {@link CatalogJanitorReport}
    */
   // will be override in tests.
-  protected Report scanForReport() throws IOException {
+  protected CatalogJanitorReport scanForReport() throws IOException {
     ReportMakingVisitor visitor = new ReportMakingVisitor(this.services);
     // Null tablename means scan all of meta.
     MetaTableAccessor.scanMetaForTableRegions(this.services.getConnection(), visitor, null);
@@ -240,7 +240,7 @@ public class CatalogJanitor extends ScheduledChore {
   /**
    * @return Returns last published Report that comes of last successful scan of hbase:meta.
    */
-  public Report getLastReport() {
+  public CatalogJanitorReport getLastReport() {
     return this.lastReport;
   }
 
@@ -493,7 +493,7 @@ public class CatalogJanitor extends ScheduledChore {
         t.put(p);
       }
       MetaTableAccessor.scanMetaForTableRegions(connection, visitor, null);
-      Report report = visitor.getReport();
+      CatalogJanitorReport report = visitor.getReport();
       LOG.info(report != null ? report.toString() : "empty");
     }
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitorReport.java

@@ -34,7 +34,7 @@ import org.apache.yetus.audience.InterfaceAudience;
  * Report made by ReportMakingVisitor
  */
 @InterfaceAudience.Private
-public class Report {
+public class CatalogJanitorReport {
   private final long now = EnvironmentEdgeManager.currentTime();
 
   // Keep Map of found split parents. These are candidates for cleanup.

hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/MetaFixer.java

@@ -76,7 +76,7 @@ public class MetaFixer {
   }
 
   public void fix() throws IOException {
-    Report report = this.masterServices.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = this.masterServices.getCatalogJanitor().getLastReport();
     if (report == null) {
       LOG.info("CatalogJanitor has not generated a report yet; run 'catalogjanitor_run' in "
         + "shell or wait until CatalogJanitor chore runs.");
@@ -93,7 +93,7 @@ public class MetaFixer {
    * If hole, it papers it over by adding a region in the filesystem and to hbase:meta. Does not
    * assign.
    */
-  void fixHoles(Report report) {
+  void fixHoles(CatalogJanitorReport report) {
     final List<Pair<RegionInfo, RegionInfo>> holes = report.getHoles();
     if (holes.isEmpty()) {
       LOG.info("CatalogJanitor Report contains no holes to fix. Skipping.");
@@ -229,7 +229,7 @@ public class MetaFixer {
   /**
    * Fix overlaps noted in CJ consistency report.
    */
-  List<Long> fixOverlaps(Report report) throws IOException {
+  List<Long> fixOverlaps(CatalogJanitorReport report) throws IOException {
     List<Long> pidList = new ArrayList<>();
     for (Set<RegionInfo> regions : calculateMerges(maxMergeCount, report.getOverlaps())) {
       RegionInfo[] regionsArray = regions.toArray(new RegionInfo[] {});

hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/ReportMakingVisitor.java

@@ -53,7 +53,7 @@ class ReportMakingVisitor implements MetaTableAccessor.CloseableVisitor {
   /**
    * Report is not done until after the close has been called.
    */
-  private Report report = new Report();
+  private CatalogJanitorReport report = new CatalogJanitorReport();
 
   /**
    * RegionInfo from previous row.
@@ -76,7 +76,7 @@ class ReportMakingVisitor implements MetaTableAccessor.CloseableVisitor {
   /**
    * Do not call until after {@link #close()}. Will throw a {@link RuntimeException} if you do.
    */
-  Report getReport() {
+  CatalogJanitorReport getReport() {
     if (!this.closed) {
       throw new RuntimeException("Report not ready until after close()");
     }

hbase-server/src/main/resources/hbase-webapps/master/hbck.jsp

@@ -20,7 +20,6 @@
 <%@ page contentType="text/html;charset=UTF-8"
          import="java.time.Instant"
          import="java.time.ZoneId"
-         import="java.util.Date"
          import="java.util.List"
          import="java.util.Map"
          import="java.util.stream.Collectors"
@@ -29,14 +28,17 @@
 %>
 <%@ page import="org.apache.hadoop.fs.Path" %>
 <%@ page import="org.apache.hadoop.hbase.client.RegionInfo" %>
-<%@ page import="org.apache.hadoop.hbase.master.HbckChore" %>
+<%@ page import="org.apache.hadoop.hbase.master.hbck.HbckChore" %>
+<%@ page import="org.apache.hadoop.hbase.master.hbck.HbckReport" %>
 <%@ page import="org.apache.hadoop.hbase.master.HMaster" %>
 <%@ page import="org.apache.hadoop.hbase.master.ServerManager" %>
 <%@ page import="org.apache.hadoop.hbase.ServerName" %>
 <%@ page import="org.apache.hadoop.hbase.util.Bytes" %>
 <%@ page import="org.apache.hadoop.hbase.util.Pair" %>
 <%@ page import="org.apache.hadoop.hbase.master.janitor.CatalogJanitor" %>
-<%@ page import="org.apache.hadoop.hbase.master.janitor.Report" %>
+<%@ page import="org.apache.hadoop.hbase.master.janitor.CatalogJanitorReport" %>
+<%@ page import="java.util.Optional" %>
+<%@ page import="org.apache.hadoop.hbase.util.EnvironmentEdgeManager" %>
 <%
   final String cacheParameterValue = request.getParameter("cache");
   final HMaster master = (HMaster) getServletContext().getAttribute(HMaster.MASTER);
@@ -55,26 +57,19 @@
     } 
   }
   HbckChore hbckChore = master.getHbckChore();
-  Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions = null;
+  HbckReport hbckReport = hbckChore == null ? null : hbckChore.getLastReport();
-  Map<String, ServerName> orphanRegionsOnRS = null;
+  String hbckReportStartTime = Optional.ofNullable(hbckReport)
-  Map<String, Path> orphanRegionsOnFS = null;
+    .map(HbckReport::getCheckingStartTimestamp)
-  long startTimestamp = 0;
+    .map(start -> ZonedDateTime.ofInstant(start, ZoneId.systemDefault()))
-  long endTimestamp = 0;
+    .map(zdt -> zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME))
-  if (hbckChore != null) {
+    .orElse(null);
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+  String hbckReportEndTime = Optional.ofNullable(hbckReport)
-    orphanRegionsOnRS = hbckChore.getOrphanRegionsOnRS();
+    .map(HbckReport::getCheckingEndTimestamp)
-    orphanRegionsOnFS = hbckChore.getOrphanRegionsOnFS();
+    .map(start -> ZonedDateTime.ofInstant(start, ZoneId.systemDefault()))
-    startTimestamp = hbckChore.getCheckingStartTimestamp();
+    .map(zdt -> zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME))
-    endTimestamp = hbckChore.getCheckingEndTimestamp();
+    .orElse(null);
-  }
-  ZonedDateTime zdt = ZonedDateTime.ofInstant(Instant.ofEpochMilli(startTimestamp),
-    ZoneId.systemDefault());
-  String iso8601start = startTimestamp == 0? "-1": zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
-  zdt = ZonedDateTime.ofInstant(Instant.ofEpochMilli(endTimestamp),
-    ZoneId.systemDefault());
-  String iso8601end = startTimestamp == 0? "-1": zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
   CatalogJanitor cj = master.getCatalogJanitor();
-  Report report = cj == null? null: cj.getLastReport();
+  CatalogJanitorReport cjReport = cj == null? null: cj.getLastReport();
   final ServerManager serverManager = master.getServerManager();
 %>
 <jsp:include page="header.jsp">
@@ -109,20 +104,22 @@
     <div class="page-header">
       <h1>HBCK Chore Report</h1>
       <p>
-        <% if (hbckChore.isDisabled()) { %>
+        <% if (hbckChore == null) { %>
+          <span>HBCK chore has not yet initialized. Try again later.</span>
+        <% } else if (hbckChore.isDisabled()) { %>
           <span>HBCK chore is currently disabled. Set hbase.master.hbck.chore.interval > 0 in the config & do a rolling-restart to enable it.</span>
-        <% } else if (startTimestamp == 0 && endTimestamp == 0){ %>
+        <% } else if (hbckReport == null) { %>
-          <span>No report created.</span>
+          <span>No Report created.</span>
-        <% } else if (startTimestamp > 0 && endTimestamp == 0){ %>
+        <% } else if (hbckReportStartTime != null && hbckReportEndTime == null) { %>
-          <span>Checking started at <%= iso8601start %>. Please wait for checking to generate a new sub-report.</span>
+          <span>Checking started at <%= hbckReportStartTime %>. Please wait for checking to generate a new sub-report.</span>
         <% } else { %>
-          <span>Checking started at <%= iso8601start %> and generated report at <%= iso8601end %>.</span>
+          <span>Checking started at <%= hbckReportStartTime %> and generated catalogJanitorReport at <%= hbckReportEndTime %>.</span>
         <% } %>
       </p>
     </div>
   </div>
 
-  <% if (inconsistentRegions != null && inconsistentRegions.size() > 0) { %>
+  <% if (hbckReport != null && hbckReport.getInconsistentRegions().size() > 0) { %>
   <div class="row">
     <div class="page-header">
       <h2>Inconsistent Regions</h2>
@@ -145,7 +142,7 @@
       <th>Location in META</th>
       <th>Reported Online RegionServers</th>
     </tr>
-    <% for (Map.Entry<String, Pair<ServerName, List<ServerName>>> entry : inconsistentRegions.entrySet()) {%>
+    <% for (Map.Entry<String, Pair<ServerName, List<ServerName>>> entry : hbckReport.getInconsistentRegions().entrySet()) { %>
     <tr>
       <td><%= entry.getKey() %></td>
       <td><%= formatServerName(master, serverManager, entry.getValue().getFirst()) %></td>
@@ -153,11 +150,11 @@
         collect(Collectors.joining(", ")) %></td>
     </tr>
     <% } %>
-    <p><%= inconsistentRegions.size() %> region(s) in set.</p>
+    <p><%= hbckReport.getInconsistentRegions().size() %> region(s) in set.</p>
   </table>
   <% } %>
 
-  <% if (orphanRegionsOnRS != null && orphanRegionsOnRS.size() > 0) { %>
+  <% if (hbckReport != null && hbckReport.getOrphanRegionsOnRS().size() > 0) { %>
   <div class="row">
     <div class="page-header">
       <h2>Orphan Regions on RegionServer</h2>
@@ -169,17 +166,17 @@
       <th>Region Name</th>
       <th>Reported Online RegionServer</th>
     </tr>
-    <% for (Map.Entry<String, ServerName> entry : orphanRegionsOnRS.entrySet()) { %>
+    <% for (Map.Entry<String, ServerName> entry : hbckReport.getOrphanRegionsOnRS().entrySet()) { %>
     <tr>
       <td><%= entry.getKey() %></td>
       <td><%= formatServerName(master, serverManager, entry.getValue()) %></td>
     </tr>
     <% } %>
-    <p><%= orphanRegionsOnRS.size() %> region(s) in set.</p>
+    <p><%= hbckReport.getOrphanRegionsOnRS().size() %> region(s) in set.</p>
   </table>
   <% } %>
 
-  <% if (orphanRegionsOnFS != null && orphanRegionsOnFS.size() > 0) { %>
+  <% if (hbckReport != null && hbckReport.getOrphanRegionsOnFS().size() > 0) { %>
   <div class="row">
     <div class="page-header">
       <h2>Orphan Regions on FileSystem</h2>
@@ -200,41 +197,41 @@
       <th>Region Encoded Name</th>
       <th>FileSystem Path</th>
     </tr>
-    <% for (Map.Entry<String, Path> entry : orphanRegionsOnFS.entrySet()) { %>
+    <% for (Map.Entry<String, Path> entry : hbckReport.getOrphanRegionsOnFS().entrySet()) { %>
     <tr>
       <td><%= entry.getKey() %></td>
       <td><%= entry.getValue() %></td>
     </tr>
     <% } %>
 
-    <p><%= orphanRegionsOnFS.size() %> region(s) in set.</p>
+    <p><%= hbckReport.getOrphanRegionsOnFS().size() %> region(s) in set.</p>
   </table>
   <% } %>
 
   <%
-    zdt = ZonedDateTime.ofInstant(Instant.ofEpochMilli(System.currentTimeMillis()),
+    Instant nowInstant = Instant.ofEpochMilli(EnvironmentEdgeManager.currentTime());
-      ZoneId.systemDefault());
+    ZonedDateTime nowZdt = ZonedDateTime.ofInstant(nowInstant, ZoneId.systemDefault());
-    String iso8601Now = zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
+    String iso8601Now = nowZdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
-    String iso8601reportTime = "-1";
+    String cjReportTime = Optional.ofNullable(cjReport)
-    if (report != null) {
+      .map(CatalogJanitorReport::getCreateTime)
-      zdt = ZonedDateTime.ofInstant(Instant.ofEpochMilli(report.getCreateTime()),
+      .map(Instant::ofEpochMilli)
-        ZoneId.systemDefault());
+      .map(start -> ZonedDateTime.ofInstant(start, ZoneId.systemDefault()))
-      iso8601reportTime = zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
+      .map(zdt -> zdt.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME))
-    }
+      .orElse(null);
   %>
   <div class="row inner_header">
     <div class="page-header">
       <h1>CatalogJanitor <em>hbase:meta</em> Consistency Issues</h1>
       <p>
-        <% if (report != null) { %>
+        <% if (cjReport != null) { %>
-          <span>Report created: <%= iso8601reportTime %> (now=<%= iso8601Now %>).</span></p>
+          <span>Report created: <%= cjReportTime %> (now=<%= iso8601Now %>).</span></p>
         <% } else { %>
-          <span>No report created.</span>
+          <span>No catalogJanitorReport created.</span>
         <% } %>
     </div>
   </div>
-  <% if (report != null && !report.isEmpty()) { %>
+  <% if (cjReport != null && !cjReport.isEmpty()) { %>
-      <% if (!report.getHoles().isEmpty()) { %>
+      <% if (!cjReport.getHoles().isEmpty()) { %>
           <div class="row inner_header">
             <div class="page-header">
               <h2>Holes</h2>
@@ -245,17 +242,17 @@
               <th>RegionInfo</th>
               <th>RegionInfo</th>
             </tr>
-            <% for (Pair<RegionInfo, RegionInfo> p : report.getHoles()) { %>
+            <% for (Pair<RegionInfo, RegionInfo> p : cjReport.getHoles()) { %>
             <tr>
               <td><span title="<%= p.getFirst() %>"><%= p.getFirst().getRegionNameAsString() %></span></td>
               <td><span title="<%= p.getSecond() %>"><%= p.getSecond().getRegionNameAsString() %></span></td>
             </tr>
             <% } %>
 
-            <p><%= report.getHoles().size() %> hole(s).</p>
+            <p><%= cjReport.getHoles().size() %> hole(s).</p>
           </table>
       <% } %>
-      <% if (!report.getOverlaps().isEmpty()) { %>
+      <% if (!cjReport.getOverlaps().isEmpty()) { %>
             <div class="row inner_header">
               <div class="page-header">
                 <h2>Overlaps</h2>
@@ -272,14 +269,14 @@
                 <th>RegionInfo</th>
                 <th>Other RegionInfo</th>
               </tr>
-              <% for (Pair<RegionInfo, RegionInfo> p : report.getOverlaps()) { %>
+              <% for (Pair<RegionInfo, RegionInfo> p : cjReport.getOverlaps()) { %>
               <tr>
-                <% if (report.getMergedRegions().containsKey(p.getFirst())) { %>
+                <% if (cjReport.getMergedRegions().containsKey(p.getFirst())) { %>
                   <td><span style="color:blue;" title="<%= p.getFirst() %>"><%= p.getFirst().getRegionNameAsString() %></span></td>
                 <% } else { %>
                   <td><span title="<%= p.getFirst() %>"><%= p.getFirst().getRegionNameAsString() %></span></td>
                 <% } %>
-                <% if (report.getMergedRegions().containsKey(p.getSecond())) { %>
+                <% if (cjReport.getMergedRegions().containsKey(p.getSecond())) { %>
                   <td><span style="color:blue;" title="<%= p.getSecond() %>"><%= p.getSecond().getRegionNameAsString() %></span></td>
                 <% } else { %>
                   <td><span title="<%= p.getSecond() %>"><%= p.getSecond().getRegionNameAsString() %></span></td>
@@ -287,10 +284,10 @@
               </tr>
               <% } %>
 
-              <p><%= report.getOverlaps().size() %> overlap(s).</p>
+              <p><%= cjReport.getOverlaps().size() %> overlap(s).</p>
             </table>
       <% } %>
-      <% if (!report.getUnknownServers().isEmpty()) { %>
+      <% if (!cjReport.getUnknownServers().isEmpty()) { %>
             <div class="row inner_header">
               <div class="page-header">
                 <h2>Unknown Servers</h2>
@@ -316,17 +313,17 @@
                 <th>RegionInfo</th>
                 <th>ServerName</th>
               </tr>
-              <% for (Pair<RegionInfo, ServerName> p: report.getUnknownServers()) { %>
+              <% for (Pair<RegionInfo, ServerName> p: cjReport.getUnknownServers()) { %>
               <tr>
                 <td><span title="<%= p.getFirst() %>"><%= p.getFirst().getRegionNameAsString() %></span></td>
                 <td><%= p.getSecond() %></td>
               </tr>
               <% } %>
 
-              <p><%= report.getUnknownServers().size() %> unknown servers(s).</p>
+              <p><%= cjReport.getUnknownServers().size() %> unknown servers(s).</p>
             </table>
       <% } %>
-      <% if (!report.getEmptyRegionInfo().isEmpty()) { %>
+      <% if (!cjReport.getEmptyRegionInfo().isEmpty()) { %>
             <div class="row inner_header">
               <div class="page-header">
                 <h2>Empty <em>info:regioninfo</em></h2>
@@ -336,13 +333,13 @@
               <tr>
                 <th>Row</th>
               </tr>
-              <% for (byte [] row: report.getEmptyRegionInfo()) { %>
+              <% for (byte [] row: cjReport.getEmptyRegionInfo()) { %>
               <tr>
                 <td><%= Bytes.toStringBinary(row) %></td>
               </tr>
               <% } %>
 
-              <p><%= report.getEmptyRegionInfo().size() %> emptyRegionInfo(s).</p>
+              <p><%= cjReport.getEmptyRegionInfo().size() %> emptyRegionInfo(s).</p>
             </table>
       <% } %>
   <% } %>

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHbck.java

@@ -19,15 +19,18 @@ package org.apache.hadoop.hbase.client;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
+import java.time.Instant;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import org.apache.hadoop.hbase.Coprocessor;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
@@ -42,6 +45,8 @@ import org.apache.hadoop.hbase.coprocessor.ObserverContext;
 import org.apache.hadoop.hbase.master.HMaster;
 import org.apache.hadoop.hbase.master.RegionState;
 import org.apache.hadoop.hbase.master.assignment.AssignmentManager;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
+import org.apache.hadoop.hbase.master.hbck.HbckReport;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
 import org.apache.hadoop.hbase.master.procedure.TableProcedureInterface;
 import org.apache.hadoop.hbase.procedure2.Procedure;
@@ -302,15 +307,14 @@ public class TestHbck {
   @Test
   public void testRunHbckChore() throws Exception {
     HMaster master = TEST_UTIL.getMiniHBaseCluster().getMaster();
-    long endTimestamp = master.getHbckChore().getCheckingEndTimestamp();
+    HbckChore hbckChore = master.getHbckChore();
+    Instant endTimestamp = Optional.ofNullable(hbckChore.getLastReport())
+      .map(HbckReport::getCheckingEndTimestamp).orElse(Instant.EPOCH);
     Hbck hbck = getHbck();
-    boolean ran = false;
+    TEST_UTIL.waitFor(TimeUnit.MINUTES.toMillis(5), hbck::runHbckChore);
-    while (!ran) {
+    HbckReport report = hbckChore.getLastReport();
-      ran = hbck.runHbckChore();
+    assertNotNull(report);
-      if (ran) {
+    assertTrue(report.getCheckingEndTimestamp().isAfter(endTimestamp));
-        assertTrue(master.getHbckChore().getCheckingEndTimestamp() > endTimestamp);
-      }
-    }
   }
 
   public static class FailingSplitAfterMetaUpdatedMasterObserver

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMasterChoreScheduled.java

@@ -28,6 +28,7 @@ import org.apache.hadoop.hbase.master.balancer.ClusterStatusChore;
 import org.apache.hadoop.hbase.master.cleaner.HFileCleaner;
 import org.apache.hadoop.hbase.master.cleaner.LogCleaner;
 import org.apache.hadoop.hbase.master.cleaner.ReplicationBarrierCleaner;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
 import org.apache.hadoop.hbase.master.janitor.CatalogJanitor;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;

hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestHbckChore.java

@@ -19,11 +19,16 @@ package org.apache.hadoop.hbase.master.assignment;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import java.time.Instant;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.Future;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
@@ -33,8 +38,9 @@ import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.TableState;
-import org.apache.hadoop.hbase.master.HbckChore;
 import org.apache.hadoop.hbase.master.TableStateManager;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
+import org.apache.hadoop.hbase.master.hbck.HbckReport;
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -75,7 +81,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
 
     hbckChore.choreForTesting();
     Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
-      hbckChore.getInconsistentRegions();
+      hbckChore.getLastReport().getInconsistentRegions();
 
     // Test for case1: Master thought this region opened, but no regionserver reported it.
     assertTrue(inconsistentRegions.containsKey(metaRegionName));
@@ -88,7 +94,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     // Reported right region location. Then not in problematic regions.
     am.reportOnlineRegions(locationInMeta, Collections.singleton(metaRegionNameAsBytes));
     hbckChore.choreForTesting();
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+    inconsistentRegions = hbckChore.getLastReport().getInconsistentRegions();
     assertFalse(inconsistentRegions.containsKey(metaRegionName));
   }
 
@@ -107,7 +113,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     // Test for case1: Master thought this region opened, but no regionserver reported it.
     hbckChore.choreForTesting();
     Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
-      hbckChore.getInconsistentRegions();
+      hbckChore.getLastReport().getInconsistentRegions();
     assertTrue(inconsistentRegions.containsKey(regionName));
     Pair<ServerName, List<ServerName>> pair = inconsistentRegions.get(regionName);
     ServerName locationInMeta = pair.getFirst();
@@ -122,7 +128,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
       serverNames.stream().filter(s -> !s.equals(tempLocationInMeta)).findFirst().get();
     am.reportOnlineRegions(anotherServer, Collections.singleton(hri.getRegionName()));
     hbckChore.choreForTesting();
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+    inconsistentRegions = hbckChore.getLastReport().getInconsistentRegions();
     assertTrue(inconsistentRegions.containsKey(regionName));
     pair = inconsistentRegions.get(regionName);
     locationInMeta = pair.getFirst();
@@ -134,7 +140,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     // Test for case3: More than one regionservers reported opened this region.
     am.reportOnlineRegions(locationInMeta, Collections.singleton(hri.getRegionName()));
     hbckChore.choreForTesting();
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+    inconsistentRegions = hbckChore.getLastReport().getInconsistentRegions();
     assertTrue(inconsistentRegions.containsKey(regionName));
     pair = inconsistentRegions.get(regionName);
     locationInMeta = pair.getFirst();
@@ -146,7 +152,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     // Reported right region location, then not in inconsistent regions.
     am.reportOnlineRegions(anotherServer, Collections.EMPTY_SET);
     hbckChore.choreForTesting();
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+    inconsistentRegions = hbckChore.getLastReport().getInconsistentRegions();
     assertFalse(inconsistentRegions.containsKey(regionName));
   }
 
@@ -164,7 +170,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
 
     hbckChore.choreForTesting();
     Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
-      hbckChore.getInconsistentRegions();
+      hbckChore.getLastReport().getInconsistentRegions();
     assertTrue(inconsistentRegions.containsKey(regionName));
     Pair<ServerName, List<ServerName>> pair = inconsistentRegions.get(regionName);
     ServerName locationInMeta = pair.getFirst();
@@ -177,7 +183,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     Mockito.when(tableStateManager.isTableState(tableName, TableState.State.DISABLED))
       .thenReturn(true);
     hbckChore.choreForTesting();
-    inconsistentRegions = hbckChore.getInconsistentRegions();
+    inconsistentRegions = hbckChore.getLastReport().getInconsistentRegions();
     assertFalse(inconsistentRegions.containsKey(regionName));
   }
 
@@ -196,7 +202,7 @@ public class TestHbckChore extends TestAssignmentManagerBase {
 
     hbckChore.choreForTesting();
     Map<String, Pair<ServerName, List<ServerName>>> inconsistentRegions =
-      hbckChore.getInconsistentRegions();
+      hbckChore.getLastReport().getInconsistentRegions();
     assertFalse(inconsistentRegions.containsKey(regionName));
   }
 
@@ -207,33 +213,35 @@ public class TestHbckChore extends TestAssignmentManagerBase {
     Configuration conf = util.getConfiguration();
 
     hbckChore.choreForTesting();
-    assertEquals(0, hbckChore.getOrphanRegionsOnFS().size());
+    assertEquals(0, hbckChore.getLastReport().getOrphanRegionsOnFS().size());
 
     HRegion.createRegionDir(conf, regionInfo, CommonFSUtils.getRootDir(conf));
     hbckChore.choreForTesting();
-    assertEquals(1, hbckChore.getOrphanRegionsOnFS().size());
+    assertEquals(1, hbckChore.getLastReport().getOrphanRegionsOnFS().size());
-    assertTrue(hbckChore.getOrphanRegionsOnFS().containsKey(regionInfo.getEncodedName()));
+    assertTrue(
+      hbckChore.getLastReport().getOrphanRegionsOnFS().containsKey(regionInfo.getEncodedName()));
 
     FSUtils.deleteRegionDir(conf, new HRegionInfo(regionInfo));
     hbckChore.choreForTesting();
-    assertEquals(0, hbckChore.getOrphanRegionsOnFS().size());
+    assertEquals(0, hbckChore.getLastReport().getOrphanRegionsOnFS().size());
   }
 
   @Test
   public void testChoreDisable() {
     // The way to disable to chore is to set hbase.master.hbck.chore.interval <= 0
     // When the interval is > 0, the chore should run.
-    long lastRunTime = hbckChore.getCheckingEndTimestamp();
+    Instant lastRunTime = Optional.ofNullable(hbckChore.getLastReport())
+      .map(HbckReport::getCheckingEndTimestamp).orElse(null);
     hbckChore.choreForTesting();
-    boolean ran = lastRunTime != hbckChore.getCheckingEndTimestamp();
+    Instant thisRunTime = Optional.ofNullable(hbckChore.getLastReport())
-    assertTrue(ran);
+      .map(HbckReport::getCheckingEndTimestamp).orElse(null);
+    assertNotNull(thisRunTime);
+    assertNotEquals(lastRunTime, thisRunTime);
 
     // When the interval <= 0, the chore shouldn't run
     master.getConfiguration().setInt("hbase.master.hbck.chore.interval", 0);
     HbckChore hbckChoreWithChangedConf = new HbckChore(master);
-    lastRunTime = hbckChoreWithChangedConf.getCheckingEndTimestamp();
     hbckChoreWithChangedConf.choreForTesting();
-    ran = lastRunTime != hbckChoreWithChangedConf.getCheckingEndTimestamp();
+    assertNull(hbckChoreWithChangedConf.getLastReport());
-    assertFalse(ran);
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitor.java

@@ -313,7 +313,7 @@ public class TestCatalogJanitor {
     final Map<HRegionInfo, Result> mergedRegions = new TreeMap<>();
     CatalogJanitor spy = spy(this.janitor);
 
-    Report report = new Report();
+    CatalogJanitorReport report = new CatalogJanitorReport();
     report.count = 10;
     report.mergedRegions.putAll(mergedRegions);
     report.splitParents.putAll(splitParents);

hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitorCluster.java

@@ -103,7 +103,7 @@ public class TestCatalogJanitorCluster {
     RegionStateStore regionStateStore =
       TEST_UTIL.getHBaseCluster().getMaster().getAssignmentManager().getRegionStateStore();
     janitor.scan();
-    Report report = janitor.getLastReport();
+    CatalogJanitorReport report = janitor.getLastReport();
     // Assert no problems.
     assertTrue(report.isEmpty());
     // Now remove first region in table t2 to see if catalogjanitor scan notices.
@@ -233,7 +233,7 @@ public class TestCatalogJanitorCluster {
   public void testHoles() throws IOException {
     CatalogJanitor janitor = TEST_UTIL.getHBaseCluster().getMaster().getCatalogJanitor();
 
-    Report report = janitor.getLastReport();
+    CatalogJanitorReport report = janitor.getLastReport();
     // Assert no problems.
     assertTrue(report.isEmpty());
     // Verify start and end region holes
@@ -248,7 +248,7 @@ public class TestCatalogJanitorCluster {
   private void fixHoles(CatalogJanitor janitor) throws IOException {
     MetaFixer metaFixer = new MetaFixer(TEST_UTIL.getHBaseCluster().getMaster());
     janitor.scan();
-    Report report = janitor.getLastReport();
+    CatalogJanitorReport report = janitor.getLastReport();
     // Verify total number of holes, 2 in t1 and t2 each and one in t3
     assertEquals("Number of holes are not matching", 5, report.getHoles().size());
     metaFixer.fix();
@@ -303,7 +303,7 @@ public class TestCatalogJanitorCluster {
   private LinkedList<Pair<RegionInfo, RegionInfo>> getHoles(CatalogJanitor janitor,
     TableName tableName) throws IOException {
     janitor.scan();
-    Report lastReport = janitor.getLastReport();
+    CatalogJanitorReport lastReport = janitor.getLastReport();
     assertFalse(lastReport.isEmpty());
     LinkedList<Pair<RegionInfo, RegionInfo>> holes = new LinkedList<>();
     for (Pair<RegionInfo, RegionInfo> hole : lastReport.getHoles()) {

hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestMetaFixer.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hbase.master.janitor;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
@@ -39,12 +40,13 @@ import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.master.HMaster;
-import org.apache.hadoop.hbase.master.HbckChore;
 import org.apache.hadoop.hbase.master.MasterServices;
 import org.apache.hadoop.hbase.master.assignment.AssignmentManager;
 import org.apache.hadoop.hbase.master.assignment.GCMultipleMergedRegionsProcedure;
 import org.apache.hadoop.hbase.master.assignment.GCRegionProcedure;
 import org.apache.hadoop.hbase.master.assignment.RegionStates;
+import org.apache.hadoop.hbase.master.hbck.HbckChore;
+import org.apache.hadoop.hbase.master.hbck.HbckReport;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
 import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.procedure2.ProcedureTestingUtility;
@@ -95,7 +97,7 @@ public class TestMetaFixer {
     MasterServices services = TEST_UTIL.getHBaseCluster().getMaster();
     int initialSize = services.getAssignmentManager().getRegionStates().getRegionStates().size();
     services.getCatalogJanitor().scan();
-    Report report = services.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = services.getCatalogJanitor().getLastReport();
     assertTrue(report.isEmpty());
     int originalCount = ris.size();
     // Remove first, last and middle region. See if hole gets plugged. Table has 26 * replicaCount
@@ -153,7 +155,7 @@ public class TestMetaFixer {
     services.getCatalogJanitor().scan();
     deleteRegion(services, ris.get(0));
     services.getCatalogJanitor().scan();
-    Report report = services.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = services.getCatalogJanitor().getLastReport();
     ris = MetaTableAccessor.getTableRegions(TEST_UTIL.getConnection(), tn);
     assertTrue(ris.isEmpty());
     MetaFixer fixer = new MetaFixer(services);
@@ -184,7 +186,7 @@ public class TestMetaFixer {
     assertTrue(ris.size() > 5);
     HMaster services = TEST_UTIL.getHBaseCluster().getMaster();
     services.getCatalogJanitor().scan();
-    Report report = services.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = services.getCatalogJanitor().getLastReport();
     assertTrue(report.isEmpty());
     // Make a simple overlap spanning second and third region.
     makeOverlap(services, ris.get(1), ris.get(3));
@@ -201,7 +203,7 @@ public class TestMetaFixer {
 
     CatalogJanitor cj = services.getCatalogJanitor();
     cj.scan();
-    Report report = cj.getLastReport();
+    CatalogJanitorReport report = cj.getLastReport();
     assertEquals(6, report.getOverlaps().size());
     assertEquals(1, MetaFixer.calculateMerges(10, report.getOverlaps()).size());
     MetaFixer fixer = new MetaFixer(services);
@@ -237,11 +239,13 @@ public class TestMetaFixer {
 
     // No orphan regions on FS
     hbckChore.choreForTesting();
-    assertEquals(0, hbckChore.getOrphanRegionsOnFS().size());
+    HbckReport hbckReport = hbckChore.getLastReport();
+    assertNotNull(hbckReport);
+    assertEquals(0, hbckReport.getOrphanRegionsOnFS().size());
 
     // No holes reported.
     cj.scan();
-    final Report postReport = cj.getLastReport();
+    final CatalogJanitorReport postReport = cj.getLastReport();
     assertTrue(postReport.isEmpty());
   }
 
@@ -255,7 +259,7 @@ public class TestMetaFixer {
 
     HMaster services = TEST_UTIL.getHBaseCluster().getMaster();
     services.getCatalogJanitor().scan();
-    Report report = services.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = services.getCatalogJanitor().getLastReport();
     assertTrue(report.isEmpty());
 
     // Make a simple overlap for t1
@@ -288,7 +292,7 @@ public class TestMetaFixer {
       HMaster services = TEST_UTIL.getHBaseCluster().getMaster();
       CatalogJanitor cj = services.getCatalogJanitor();
       cj.scan();
-      Report report = cj.getLastReport();
+      CatalogJanitorReport report = cj.getLastReport();
       assertEquals(6, report.getOverlaps().size());
       assertEquals(2, MetaFixer.calculateMerges(5, report.getOverlaps()).size());
 
@@ -311,7 +315,7 @@ public class TestMetaFixer {
       HBaseTestingUtility.await(200, () -> {
         try {
           cj.scan();
-          final Report postReport = cj.getLastReport();
+          final CatalogJanitorReport postReport = cj.getLastReport();
           RegionStates regionStates = am.getRegionStates();
 
           // Make sure that two merged regions are opened and GCs are done.
@@ -354,7 +358,7 @@ public class TestMetaFixer {
 
       // No holes reported.
       cj.scan();
-      final Report postReport = cj.getLastReport();
+      final CatalogJanitorReport postReport = cj.getLastReport();
       assertTrue(postReport.isEmpty());
 
     } finally {
@@ -379,7 +383,7 @@ public class TestMetaFixer {
     HMaster services = TEST_UTIL.getHBaseCluster().getMaster();
     CatalogJanitor cj = services.getCatalogJanitor();
     cj.scan();
-    Report report = cj.getLastReport();
+    CatalogJanitorReport report = cj.getLastReport();
     assertTrue(report.isEmpty());
     RegionInfo overlapRegion = makeOverlap(services, ris.get(1), ris.get(2));
 
@@ -440,7 +444,7 @@ public class TestMetaFixer {
     assertTrue(ris.size() > 5);
     MasterServices services = TEST_UTIL.getHBaseCluster().getMaster();
     services.getCatalogJanitor().scan();
-    Report report = services.getCatalogJanitor().getLastReport();
+    CatalogJanitorReport report = services.getCatalogJanitor().getLastReport();
     assertTrue(report.isEmpty());
     // Make a simple overlap spanning second and third region.
     makeOverlap(services, ris.get(1), ris.get(5));
@@ -464,7 +468,7 @@ public class TestMetaFixer {
     HBaseTestingUtility.await(10, () -> {
       try {
         services.getCatalogJanitor().scan();
-        final Report postReport = services.getCatalogJanitor().getLastReport();
+        final CatalogJanitorReport postReport = services.getCatalogJanitor().getLastReport();
         return postReport.isEmpty();
       } catch (Exception e) {
         throw new RuntimeException(e);