Did anyone try DRBD (http://www.drbd.org/) for mirroring the fsimage
and editlogs to another machine?
Another idea which would involve code changes is to go to something
like Terracotta (http://www.terracottatech.com/) essentially allowing
multiple machines simultaneously to play the role of a namenode. I
only played around with their samples, but if it works as advertised
it could be a nice way to spread the load and achieve HA.
Disclaimer: Not affiliated with DRDB or Terracotta. Just in need of an
(ideally automatic) failover solution to protect my weekends.
On Nov 21, 2007, at 6:51 AM, j2eeiscool wrote:
Hi Dbruba,
Thanx for your reply.
On the first part (NameNode HA and failover), our experience with
NFS has
not been very good.
Is having a Db as a backing store for NameNode an option (I
understand that
this may not be part of the current release 0.15.0 and would be a new
feature)?
-Taj
Dhruba Borthakur wrote:
Here is some info on recovering from a failed Namenode:
http://wiki.apache.org/lucene-hadoop/NameNodeFailover
The fact that there is a single Namenode does mean that it could
possibly become the bottleneck when many thousands of clients/
Datanodes
run on the cluster simultaneously. However, the design is such that
it
is scalable to a huge number of clients/Datanodes. Also, work is
going
on continuously to improve scalabilty.
Thanks,
Dhruba
-----Original Message-----
From: j2eeiscool [mailto:[EMAIL PROTECTED]
Sent: Tuesday, November 20, 2007 12:47 PM
To: [email protected]
Subject: NameNode HA
Hi,
Based on the documentation I have read, there is one instance of a
NameNode.
Are there recommended approaches on making the NameNode HA:
1.Have a backup which takes over. Data between primary and backup is
shared
thru shared files , DB etc.
Also does having a single NameNode limit the no. of concurrent HDFS
clients
? I understand that HDFS Readers and Writers use the DataNode(s)
eventually,
but the initial access point is the NameNode.
I would really appreciate help on these (I am evaluating HDFS for
use as
a
Concurrent, Reliable, Performant Distributed File System).
Thanx,
Taj
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