svn commit: r1429617 - in /lucene/dev/branches/branch_4x: ./ lucene/ lucene/CHANGES.txt lucene/core/ lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java

[mi...@apache.org]

Author: mikemccand
Date: Sun Jan  6 23:54:20 2013
New Revision: 1429617

URL: http://svn.apache.org/viewvc?rev=1429617&view=rev
Log:
LUCENE-4661: lower default maxThread/MergeCount in CMS

Modified:
    lucene/dev/branches/branch_4x/   (props changed)
    lucene/dev/branches/branch_4x/lucene/   (props changed)
    lucene/dev/branches/branch_4x/lucene/CHANGES.txt   (contents, props changed)
    lucene/dev/branches/branch_4x/lucene/core/   (props changed)
    lucene/dev/branches/branch_4x/lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java

Modified: lucene/dev/branches/branch_4x/lucene/CHANGES.txt
URL: http://svn.apache.org/viewvc/lucene/dev/branches/branch_4x/lucene/CHANGES.txt?rev=1429617&r1=1429616&r2=1429617&view=diff
==============================================================================
--- lucene/dev/branches/branch_4x/lucene/CHANGES.txt (original)
+++ lucene/dev/branches/branch_4x/lucene/CHANGES.txt Sun Jan  6 23:54:20 2013
@@ -370,6 +370,10 @@ Optimizations
 
 * LUCENE-4598: PayloadIterator no longer uses top-level IndexReader to iterate on the
   posting's payload. (Shai Erera, Michael McCandless)
+
+* LUCENE-4661: Drop default maxThreadCount to 1 and maxMergeCount to 2
+  in ConcurrentMergeScheduler, for faster merge performance on
+  spinning-magnet drives (Mike McCandless)
   
 Documentation
 

Modified: lucene/dev/branches/branch_4x/lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java
URL: http://svn.apache.org/viewvc/lucene/dev/branches/branch_4x/lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java?rev=1429617&r1=1429616&r2=1429617&view=diff
==============================================================================
--- lucene/dev/branches/branch_4x/lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java (original)
+++ lucene/dev/branches/branch_4x/lucene/core/src/java/org/apache/lucene/index/ConcurrentMergeScheduler.java Sun Jan  6 23:54:20 2013
@@ -55,14 +55,15 @@ public class ConcurrentMergeScheduler ex
   // forcefully pause the larger ones, letting the smaller
   // ones run, up until maxMergeCount merges at which point
   // we forcefully pause incoming threads (that presumably
-  // are the ones causing so much merging).  We dynamically
-  // default this from 1 to 3, depending on how many cores
-  // you have:
-  private int maxThreadCount = Math.max(1, Math.min(3, Runtime.getRuntime().availableProcessors()/2));
+  // are the ones causing so much merging).  We default to 1
+  // here: tests on spinning-magnet drives showed slower
+  // indexing perf if more than one merge thread runs at
+  // once (though on an SSD it was faster):
+  private int maxThreadCount = 1;
 
   // Max number of merges we accept before forcefully
   // throttling the incoming threads
-  private int maxMergeCount = maxThreadCount+2;
+  private int maxMergeCount = 2;
 
   /** {@link Directory} that holds the index. */
   protected Directory dir;