Author: dmeil
Date: Thu Feb 16 21:56:57 2012
New Revision: 1245199
URL: http://svn.apache.org/viewvc?rev=1245199&view=rev
Log:
hbase-5397. performance.xml, configuration.xml - correction to ZK config.
Modified:
hbase/trunk/src/docbkx/configuration.xml
hbase/trunk/src/docbkx/performance.xml
Modified: hbase/trunk/src/docbkx/configuration.xml
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/configuration.xml?rev=1245199&r1=1245198&r2=1245199&view=diff
==============================================================================
--- hbase/trunk/src/docbkx/configuration.xml (original)
+++ hbase/trunk/src/docbkx/configuration.xml Thu Feb 16 21:56:57 2012
@@ -659,9 +659,16 @@ stopping hbase...............</programli
only but in production it is recommended that you run a
ZooKeeper ensemble of 3, 5 or 7 machines; the more members an
ensemble has, the more tolerant the ensemble is of host
- failures. Also, run an odd number of machines. There can be no
- quorum if the number of members is an even number. Give each
- ZooKeeper server around 1GB of RAM, and if possible, its own
+ failures. Also, run an odd number of machines. In ZooKeeper,
+ an even number of peers is supported, but it is normally not
used
+ because an even sized ensemble requires, proportionally, more
peers
+ to form a quorum than an odd sized ensemble requires. For
example, an
+ ensemble with 4 peers requires 3 to form a quorum, while an
ensemble with
+ 5 also requires 3 to form a quorum. Thus, an ensemble of 5
allows 2 peers to
+ fail, and thus is more fault tolerant than the ensemble of 4,
which allows
+ only 1 down peer.
+ </para>
+ <para>Give each ZooKeeper server around 1GB of RAM, and if
possible, its own
dedicated disk (A dedicated disk is the best thing you can do
to ensure a performant ZooKeeper ensemble). For very heavily
loaded clusters, run ZooKeeper servers on separate machines
Modified: hbase/trunk/src/docbkx/performance.xml
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/performance.xml?rev=1245199&r1=1245198&r2=1245199&view=diff
==============================================================================
--- hbase/trunk/src/docbkx/performance.xml (original)
+++ hbase/trunk/src/docbkx/performance.xml Thu Feb 16 21:56:57 2012
@@ -188,7 +188,12 @@
</section>
</section>
-
+ <section xml:id="perf.zookeeper">
+ <title>ZooKeeper</title>
+ <para>See <xref linkend="zookeeper"/> for information on configuring
ZooKeeper, and see the part
+ about having a dedicated disk.
+ </para>
+ </section>
<section xml:id="perf.schema">
<title>Schema Design</title>
