HBASE-27321 The ReplicationLogCleaner is not thread safe but can be c…

…alled from different threads at the same time (apache#4730)

Signed-off-by: Xin Sun <[email protected]>
(cherry picked from commit 37651ee)

hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java

@@ -182,13 +182,14 @@ public boolean scheduleChore(ScheduledChore chore) {
    * @param chore The Chore to be rescheduled. If the chore is not scheduled with this ChoreService
    *              yet then this call is equivalent to a call to scheduleChore.
    */
-  private void rescheduleChore(ScheduledChore chore) {
+  private void rescheduleChore(ScheduledChore chore, boolean immediately) {
     if (scheduledChores.containsKey(chore)) {
       ScheduledFuture<?> future = scheduledChores.get(chore);
       future.cancel(false);
     }
-    ScheduledFuture<?> future = scheduler.scheduleAtFixedRate(chore, chore.getInitialDelay(),
-      chore.getPeriod(), chore.getTimeUnit());
+    // set initial delay to 0 as we want to run it immediately
+    ScheduledFuture<?> future = scheduler.scheduleAtFixedRate(chore,
+      immediately ? 0 : chore.getPeriod(), chore.getPeriod(), chore.getTimeUnit());
     scheduledChores.put(chore, future);
   }
 
@@ -244,7 +245,7 @@ public synchronized boolean isChoreScheduled(ScheduledChore chore) {
       allowedOnPath = ".*/org/apache/hadoop/hbase/ScheduledChore.java")
   synchronized void triggerNow(ScheduledChore chore) {
     assert chore.getChoreService() == this;
-    rescheduleChore(chore);
+    rescheduleChore(chore, true);
   }
 
   /** Returns number of chores that this service currently has scheduled */
@@ -343,7 +344,7 @@ synchronized void onChoreMissedStartTime(ScheduledChore chore) {
     // the chore is NOT rescheduled, future executions of this chore will be delayed more and
     // more on each iteration. This hurts us because the ScheduledThreadPoolExecutor allocates
     // idle threads to chores based on how delayed they are.
-    rescheduleChore(chore);
+    rescheduleChore(chore, false);
     printChoreDetails("onChoreMissedStartTime", chore);
   }
 

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

@@ -34,6 +34,8 @@
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.Collectors;
 import org.apache.hadoop.conf.Configuration;
@@ -1572,8 +1574,16 @@ public RunCatalogScanResponse runCatalogScan(RpcController c, RunCatalogScanRequ
   public RunCleanerChoreResponse runCleanerChore(RpcController c, RunCleanerChoreRequest req)
     throws ServiceException {
     rpcPreCheck("runCleanerChore");
-    boolean result = master.getHFileCleaner().runCleaner() && master.getLogCleaner().runCleaner();
-    return ResponseConverter.buildRunCleanerChoreResponse(result);
+    try {
+      CompletableFuture<Boolean> fileCleanerFuture = master.getHFileCleaner().triggerCleanerNow();
+      CompletableFuture<Boolean> logCleanerFuture = master.getLogCleaner().triggerCleanerNow();
+      boolean result = fileCleanerFuture.get() && logCleanerFuture.get();
+      return ResponseConverter.buildRunCleanerChoreResponse(result);
+    } catch (InterruptedException e) {
+      throw new ServiceException(e);
+    } catch (ExecutionException e) {
+      throw new ServiceException(e.getCause());
+    }
   }
 
   @Override

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

@@ -23,7 +23,6 @@
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
@@ -81,6 +80,8 @@ public abstract class CleanerChore<T extends FileCleanerDelegate> extends Schedu
   private final AtomicBoolean enabled = new AtomicBoolean(true);
   protected List<T> cleanersChain;
   protected List<String> excludeDirs;
+  private CompletableFuture<Boolean> future;
+  private boolean forceRun;
 
   public CleanerChore(String name, final int sleepPeriod, final Stoppable s, Configuration conf,
     FileSystem fs, Path oldFileDir, String confKey, DirScanPool pool) {
@@ -168,10 +169,10 @@ static int calculatePoolSize(String poolSize) {
    * @param confKey key to get the file cleaner classes from the configuration
    */
   private void initCleanerChain(String confKey) {
-    this.cleanersChain = new LinkedList<>();
-    String[] logCleaners = conf.getStrings(confKey);
-    if (logCleaners != null) {
-      for (String className : logCleaners) {
+    this.cleanersChain = new ArrayList<>();
+    String[] cleaners = conf.getStrings(confKey);
+    if (cleaners != null) {
+      for (String className : cleaners) {
         className = className.trim();
         if (className.isEmpty()) {
           continue;
@@ -208,42 +209,87 @@ private T newFileCleaner(String className, Configuration conf) {
     }
   }
 
+  @Override
+  protected boolean initialChore() {
+    synchronized (this) {
+      if (forceRun) {
+        // wake up the threads waiting in triggerCleanerNow, as a triggerNow may triggers the first
+        // loop where we will only call initialChore. We need to trigger another run immediately.
+        forceRun = false;
+        notifyAll();
+      }
+    }
+    return true;
+  }
+
   @Override
   protected void chore() {
-    if (getEnabled()) {
-      try {
-        pool.latchCountUp();
-        if (runCleaner()) {
-          LOG.trace("Cleaned all WALs under {}", oldFileDir);
+    CompletableFuture<Boolean> f;
+    synchronized (this) {
+      if (!enabled.get()) {
+        if (!forceRun) {
+          LOG.trace("Cleaner chore {} disabled! Not cleaning.", getName());
+          return;
         } else {
-          LOG.trace("WALs outstanding under {}", oldFileDir);
+          LOG.info("Force executing cleaner chore {} when disabled", getName());
         }
-      } finally {
-        pool.latchCountDown();
       }
+      if (future != null) {
+        LOG.warn("A cleaner chore {}'s run is in progress, give up running", getName());
+        return;
+      }
+      f = new CompletableFuture<>();
+      future = f;
+      notifyAll();
+    }
+    pool.latchCountUp();
+    try {
+      preRunCleaner();
+      pool.execute(() -> traverseAndDelete(oldFileDir, true, f));
+      if (f.get()) {
+        LOG.trace("Cleaned all files under {}", oldFileDir);
+      } else {
+        LOG.trace("Files outstanding under {}", oldFileDir);
+      }
+    } catch (Exception e) {
+      LOG.info("Failed to traverse and delete the dir: {}", oldFileDir, e);
+    } finally {
+      postRunCleaner();
+      synchronized (this) {
+        future = null;
+        forceRun = false;
+      }
+      pool.latchCountDown();
       // After each cleaner chore, checks if received reconfigure notification while cleaning.
       // First in cleaner turns off notification, to avoid another cleaner updating pool again.
       // This cleaner is waiting for other cleaners finishing their jobs.
       // To avoid missing next chore, only wait 0.8 * period, then shutdown.
       pool.tryUpdatePoolSize((long) (0.8 * getTimeUnit().toMillis(getPeriod())));
-    } else {
-      LOG.trace("Cleaner chore disabled! Not cleaning.");
     }
   }
 
   private void preRunCleaner() {
     cleanersChain.forEach(FileCleanerDelegate::preClean);
   }
 
-  public boolean runCleaner() {
-    preRunCleaner();
-    try {
-      CompletableFuture<Boolean> future = new CompletableFuture<>();
-      pool.execute(() -> traverseAndDelete(oldFileDir, true, future));
-      return future.get();
-    } catch (Exception e) {
-      LOG.info("Failed to traverse and delete the dir: {}", oldFileDir, e);
-      return false;
+  private void postRunCleaner() {
+    cleanersChain.forEach(FileCleanerDelegate::postClean);
+  }
+
+  /**
+   * Trigger the cleaner immediately and return a CompletableFuture for getting the result. Return
+   * {@code true} means all the old files have been deleted, otherwise {@code false}.
+   */
+  public synchronized CompletableFuture<Boolean> triggerCleanerNow() throws InterruptedException {
+    for (;;) {
+      if (future != null) {
+        return future;
+      }
+      forceRun = true;
+      if (!triggerNow()) {
+        return CompletableFuture.completedFuture(false);
+      }
+      wait();
     }
   }
 
@@ -396,9 +442,6 @@ int getChorePoolSize() {
     return pool.getSize();
   }
 
-  /**
-   * n
-   */
   public boolean setEnabled(final boolean enabled) {
     return this.enabled.getAndSet(enabled);
   }
@@ -449,7 +492,7 @@ private void traverseAndDelete(Path dir, boolean root, CompletableFuture<Boolean
         CompletableFuture.allOf(futures.toArray(new CompletableFuture[futures.size()])),
         (voidObj, e) -> {
           if (e != null) {
-            result.completeExceptionally(e);
+            result.completeExceptionally(FutureUtils.unwrapCompletionException(e));
             return;
           }
           try {

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

@@ -49,6 +49,12 @@ public interface FileCleanerDelegate extends Configurable, Stoppable {
   default void preClean() {
   }
 
+  /**
+   * Used to do some cleanup work
+   */
+  default void postClean() {
+  }
+
   /**
    * Check if a empty directory with no subdirs or subfiles can be deleted
    * @param dir Path of the directory

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

@@ -66,6 +66,12 @@ public void preClean() {
     }
   }
 
+  @Override
+  public void postClean() {
+    // release memory
+    wals = null;
+  }
+
   @Override
   public Iterable<FileStatus> getDeletableFiles(Iterable<FileStatus> files) {
     // all members of this class are null if replication is disabled,

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

@@ -451,7 +451,7 @@ public void testMergeRegion() throws Exception {
       // set file modify time and then run cleaner
       long time = EnvironmentEdgeManager.currentTime() - TimeToLiveHFileCleaner.DEFAULT_TTL * 1000;
       traverseAndSetFileTime(HFileArchiveUtil.getArchivePath(conf), time);
-      UTIL.getMiniHBaseCluster().getMaster().getHFileCleaner().runCleaner();
+      UTIL.getMiniHBaseCluster().getMaster().getHFileCleaner().triggerCleanerNow().get();
       // scan snapshot
       try (TableSnapshotScanner scanner = new TableSnapshotScanner(conf,
         UTIL.getDataTestDirOnTestFS(snapshotName), snapshotName, new Scan(bbb, yyy))) {