[accumulo] branch 1.9 updated: Only requeue compaction when there was activity (#759)

[kt...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

kturner pushed a commit to branch 1.9
in repository https://gitbox.apache.org/repos/asf/accumulo.git


The following commit(s) were added to refs/heads/1.9 by this push:
     new b6409ef  Only requeue compaction when there was activity (#759)
b6409ef is described below

commit b6409effe1df98a1a0217bb97a87757477ea1d78
Author: Keith Turner <kt...@apache.org>
AuthorDate: Fri Nov 9 10:36:26 2018 -0500

    Only requeue compaction when there was activity (#759)
---
 .../apache/accumulo/tserver/tablet/CompactionRunner.java | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/server/tserver/src/main/java/org/apache/accumulo/tserver/tablet/CompactionRunner.java b/server/tserver/src/main/java/org/apache/accumulo/tserver/tablet/CompactionRunner.java
index 8fab78c..8de7a9e 100644
--- a/server/tserver/src/main/java/org/apache/accumulo/tserver/tablet/CompactionRunner.java
+++ b/server/tserver/src/main/java/org/apache/accumulo/tserver/tablet/CompactionRunner.java
@@ -41,12 +41,18 @@ final class CompactionRunner implements Runnable, Comparable<CompactionRunner> {
       return;
     }
 
-    tablet.majorCompact(reason, queued);
+    CompactionStats stats = tablet.majorCompact(reason, queued);
 
-    // if there is more work to be done, queue another major compaction
-    synchronized (tablet) {
-      if (reason == MajorCompactionReason.NORMAL && tablet.needsMajorCompaction(reason))
-        tablet.initiateMajorCompaction(reason);
+    // Some compaction strategies may always return true for shouldCompact() because they need to
+    // make blocking calls to gather information. Without the following check these strategies would
+    // endlessly requeue. So only check if a subsequent compaction is needed if the previous
+    // compaction actually did something.
+    if (stats != null && stats.getEntriesRead() > 0) {
+      // if there is more work to be done, queue another major compaction
+      synchronized (tablet) {
+        if (reason == MajorCompactionReason.NORMAL && tablet.needsMajorCompaction(reason))
+          tablet.initiateMajorCompaction(reason);
+      }
     }
   }