From 573ecf2e16d618785d04871c5b61e29073eef5d5 Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Mon, 14 Feb 2011 22:56:35 +0000
Subject: [PATCH] SOLR-2342: don't let hot add/updates starve commit

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1070691 13f79535-47bb-0310-9956-ffa450edef68
---
 .../src/java/org/apache/solr/update/DirectUpdateHandler2.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/solr/src/java/org/apache/solr/update/DirectUpdateHandler2.java b/solr/src/java/org/apache/solr/update/DirectUpdateHandler2.java
index 55f9ac77fc0..5106b1cb0aa 100644
--- a/solr/src/java/org/apache/solr/update/DirectUpdateHandler2.java
+++ b/solr/src/java/org/apache/solr/update/DirectUpdateHandler2.java
@@ -91,7 +91,9 @@ public class DirectUpdateHandler2 extends UpdateHandler {
   public DirectUpdateHandler2(SolrCore core) throws IOException {
     super(core);
 
-    ReadWriteLock rwl = new ReentrantReadWriteLock();
+    // Pass fairness=true so commit request is not starved
+    // when add/updates are running hot (SOLR-2342):
+    ReadWriteLock rwl = new ReentrantReadWriteLock(true);
     iwAccess = rwl.readLock();
     iwCommit = rwl.writeLock();