Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
HBase >> mail # user >> Odd WARN in hbase 0.94.2


+
Bryan Beaudreault 2013-03-05, 21:28
+
Kevin Odell 2013-03-05, 21:35
+
Bryan Beaudreault 2013-03-05, 22:17
+
Kevin Odell 2013-03-06, 20:43
+
Bryan Beaudreault 2013-03-06, 21:04
Copy link to this message
-
RE: Odd WARN in hbase 0.94.2
Hi Kevin
              Thanks for the information.  In HBase book, we have added a note on how to use short circuit reads.. Can we update it accordingly? Which version of HDFS need this attribute to be present in DN side also?  It would be great if you can file a JIRA and give a change in the description on the usage...

-Anoop-
________________________________________
From: Kevin O'dell [[EMAIL PROTECTED]]
Sent: Thursday, March 07, 2013 2:13 AM
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Subject: Re: Odd WARN in hbase 0.94.2

Hi Byran,

One of engineers wanted me to pass this recommendation along:

The issue here is mostly likely a missing configuration.

We need to have this configuration on both the DataNode and RegionServer:
<property>
  <name>dfs.domain.socket.path</name>
  <value>/var/run/hadoop-hdfs/dn._PORT</value>
</property>
<property>
  <name>dfs.client.read.shortcircuit</name>
  <value>true</value>
</property>

In CDH4.1 and earlier, the DN didn't need to be configured to use SCR,
so most likely he does not have dfs.client.read.shortcircuit set in
hdfs-site.xml.  Adding that should fix it

On Tue, Mar 5, 2013 at 5:17 PM, Bryan Beaudreault
<[EMAIL PROTECTED]>wrote:

> Yep we do have that property set to that value.  The file does not seem to
> exist when I try ls'ing it myself.  I'm not sure where it comes from or how
> it should be created.
>
>
> On Tue, Mar 5, 2013 at 4:35 PM, Kevin O'dell <[EMAIL PROTECTED]
> >wrote:
>
> > Bryan,
> >
> >   What permissions did you set for the SCRs?  The DNs need
> >
> > <property>
> > <name>dfs.datanode.data.dir.perm</name>
> > <value>755</name>
> > </property>
> >
> >
> > On Tue, Mar 5, 2013 at 4:28 PM, Bryan Beaudreault
> > <[EMAIL PROTECTED]>wrote:
> >
> > > We are running hbase 0.94.2, cdh4.2 edition.  We have the local read
> > > shortcut enabled.  Since updating to this version I've seen a bunch of
> > WARN
> > > messages corresponding to exceptions trying to connect to what looks
> like
> > > the local DN.
> > >
> > > As far as I can tell it doesn't appear to be having much affect on the
> RS
> > > but it'd be nice to clear it up and know for sure that it doesn't
> > indicate
> > > some problem. Has anyone ever seen this and know what it is or how to
> fix
> > > it?
> > >
> > > http://pastebin.com/PA6Y9pJN
> > >
> > > Thanks!
> > >
> >
> >
> >
> > --
> > Kevin O'Dell
> > Customer Operations Engineer, Cloudera
> >
>

--
Kevin O'Dell
Customer Operations Engineer, Cloudera
+
Bryan Beaudreault 2013-03-07, 03:56
+
Anoop Sam John 2013-03-07, 09:08
+
Harsh J 2013-03-07, 11:06