Author: dmeil
Date: Wed Sep 14 20:25:51 2011
New Revision: 1170834
URL: http://svn.apache.org/viewvc?rev=1170834&view=rev
Log:
HBASE-4409. book. Fixed cycle in config section and wiki with "too many open
files" error.
Modified:
hbase/trunk/src/docbkx/configuration.xml
hbase/trunk/src/docbkx/troubleshooting.xml
Modified: hbase/trunk/src/docbkx/configuration.xml
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/configuration.xml?rev=1170834&r1=1170833&r2=1170834&view=diff
==============================================================================
--- hbase/trunk/src/docbkx/configuration.xml (original)
+++ hbase/trunk/src/docbkx/configuration.xml Wed Sep 14 20:25:51 2011
@@ -104,14 +104,19 @@ to ensure well-formedness of your docume
<para>HBase is a database. It uses a lot of files all at the same
time.
The default ulimit -n -- i.e. user file limit -- of 1024 on most *nix
systems
is insufficient (On mac os x its 256). Any significant amount of
loading will
- lead you to <link
xlink:href="http://wiki.apache.org/hadoop/Hbase/FAQ#A6";>FAQ: Why do I
- see "java.io.IOException...(Too many open files)" in my logs?</link>.
- You may also notice errors such as <programlisting>
+ lead you to <xref linkend="trouble.rs.runtime.filehandles"/>.
+ You may also notice errors such as... <programlisting>
2010-04-06 03:04:37,542 INFO org.apache.hadoop.hdfs.DFSClient: Exception
increateBlockOutputStream java.io.EOFException
2010-04-06 03:04:37,542 INFO org.apache.hadoop.hdfs.DFSClient:
Abandoning block blk_-6935524980745310745_1391901
</programlisting> Do yourself a favor and change the upper bound on the
- number of file descriptors. Set it to north of 10k. See the above
- referenced FAQ for how. You should also up the hbase users'
+ number of file descriptors. Set it to north of 10k. The math runs
roughly as follows: per ColumnFamily
+ there is at least one StoreFile and possibly up to 5 or 6 if the
region is under load. Multiply the
+ average number of StoreFiles per ColumnFamily times the number of
regions per RegionServer. For example, assuming
+ that a schema had 3 ColumnFamilies per region with an average of 3
StoreFiles per ColumnFamily,
+ and there are 100 regions per RegionServer, the JVM will open 3 * 3 *
100 = 900 file descriptors
+ (not counting open jar files, config files, etc.)
+ </para>
+ <para>You should also up the hbase users'
<varname>nproc</varname> setting; under load, a low-nproc
setting could manifest as <classname>OutOfMemoryError</classname>
<footnote><para>See Jack Levin's <link xlink:href="">major hdfs
issues</link>
Modified: hbase/trunk/src/docbkx/troubleshooting.xml
URL:
http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/troubleshooting.xml?rev=1170834&r1=1170833&r2=1170834&view=diff
==============================================================================
--- hbase/trunk/src/docbkx/troubleshooting.xml (original)
+++ hbase/trunk/src/docbkx/troubleshooting.xml Wed Sep 14 20:25:51 2011
@@ -602,7 +602,14 @@ java.lang.UnsatisfiedLinkError: no gplco
<section xml:id="trouble.rs.runtime.filehandles">
<title>java.io.IOException...(Too many open files)</title>
<para>
- See the Getting Started section on <link linkend="ulimit">ulimit
and nproc configuration</link>.
+ If you see log messages like this...
+<programlisting>
+2010-09-13 01:24:17,336 WARN org.apache.hadoop.hdfs.server.datanode.DataNode:
+Disk-related IOException in BlockReceiver constructor. Cause is
java.io.IOException: Too many open files
+ at java.io.UnixFileSystem.createFileExclusively(Native Method)
+ at java.io.File.createNewFile(File.java:883)
+</programlisting>
+ ... see the Getting Started section on <link
linkend="ulimit">ulimit and nproc configuration</link>.
</para>
</section>
<section xml:id="trouble.rs.runtime.xceivers">
