HBASE-4714 Don't ship w/ icms enabled by default; REDO

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1196120 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -731,6 +731,7 @@ Release 0.92.0 - Unreleased
    HBASE-4699  Cleanup the UIs
    HBASE-4552  Remove trivial 0.90 deprecated code from 0.92 and trunk.
                (Jonathan Hsieh)
+   HBASE-4714  Don't ship w/ icms enabled by default
 
   NEW FEATURES
    HBASE-2001  Coprocessors: Colocate user code with regions (Mingjie Lai via

conf/hbase-env.sh

@@ -34,7 +34,7 @@
 # Below are what we set by default.  May only work with SUN JVM.
 # For more on why as well as other possible settings,
 # see http://wiki.apache.org/hadoop/PerformanceTuning
-export HBASE_OPTS="-ea -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode"
+export HBASE_OPTS="-ea -XX:+UseConcMarkSweepGC"
 
 # Uncomment below to enable java garbage collection logging in the .out file.
 # export HBASE_OPTS="$HBASE_OPTS -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps" 

src/docbkx/performance.xml

@@ -119,7 +119,10 @@
         must be explicitly enabled in HBase 0.90.x (Its defaulted to be on in
         0.92.x HBase). See <code>hbase.hregion.memstore.mslab.enabled</code>
         to true in your <classname>Configuration</classname>. See the cited
-        slides for background and detail.</para>
+        slides for background and detail<footnote><para>The latest jvms do better
+        regards fragmentation so make sure you are running a recent release.
+        Read down in the message,
+        <link xlink:href="http://osdir.com/ml/hotspot-gc-use/2011-11/msg00002.html">Identifying concurrent mode failures caused by fragmentation</link>.</para></footnote>.</para>
         <para>For more information about GC logs, see <xref linkend="trouble.log.gc" />.
         </para>
       </section>