What is the value of dfs.name.edits.dir?
Is it the default, which would be the same as dfs.name.dir, or is it different?
Thanks,
--Konstantin
On 2/9/2010 12:05 PM, Allen, Jonathan wrote:
Todd,
Unfortunately my test system is air gapped away from the internet so I haven't
been able to transfer my test case across yet but the basic steps as are
follows:
1) start-dfs (also shutdown the secondary to make sure that it didn't
checkpoint away the edit log)
2) create lots of small files so that there is a large edit log (I created
about 4,500 files resulting in an edit log of just over 1MB).
3) stop-dfs
4) start-dfs
5) wait for name node to start reading the edit log but not long enough for it
to finish reading it (I waited for a couple of seconds).
6) stop-dfs
7) start-dfs
8) listing the hdfs directory now shows it in the same state as at step (1)
rather than the correct state as at step (3).
This was running with the Yahoo distro of 0.20.1.
The dfs.name.dir is configured to use directories on 2 local drives and 1 NFS
mounted drive.
Thanks,
Jonathan
Jonathan Allen
UKGP, NS&R, Defence and Security
HP Enterprise Services
Telephone +44 1682 292101
Email jonathan.allen...@hp.com
Street address, Unit 29, Alexandra Way, Ashchurch Business Park, Tewkesbury,
Gloucestershire. GL20 8NB
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-----Original Message-----
From: Todd Lipcon [mailto:t...@cloudera.com]
Sent: 09 February 2010 01:11
To: hdfs-dev@hadoop.apache.org
Subject: Re: Name Node Corruption When Shutdown Too Soon
Hi Jonathan,
Another question: how have you configured dfs.name.dir? Do you have
several directories configured?
Thanks
-Todd
On Mon, Feb 8, 2010 at 4:45 PM, Todd Lipcon<t...@cloudera.com> wrote:
Hey Jonathan,
As Konstantin mentioned, I've been looking into a couple issues that
could be related. At first glance it doesn't sound like you've run
into quite the same thing.
What version did you see this on? The steps to reproduce are something like:
1) Start a NN
2) Perform a bunch of edits so there is a large edit log
3) kill -9 the NN
4) start the NN again
5) while it is in the middle of replaying edits, kill -9 it again
6) start the NN, and lose all the previous edits?
Or did I misunderstand what happened? If that sounds right, I'll give
it a go and see if I can reproduce.
Thanks
-Todd
On Sun, Feb 7, 2010 at 8:45 AM, Allen, Jonathan<jonathan.all...@hp.com> wrote:
I've come across a name node bug and just wanted to check if it's a known issue
before I formally raise it (I've had a quick look through the database but
couldn't see anything obvious).
If the name node is shut down before it has completed reading through the edit
log then the edit log gets removed without the image file being updated. This
results in name node reverting to its previously saved state (out of sync with
the data nodes) and the most recent edits getting lost.
Does anybody recognise this as a known issue or should I raise it?
Thanks,
Jonathan Allen
UKGP, NS&R, Defence and Security
HP Enterprise Services
Telephone +44 1682 292101
Email jonathan.allen...@hp.com
Street address, Unit 29, Alexandra Way, Ashchurch Business Park, Tewkesbury,
Gloucestershire. GL20 8NB
Hewlett-Packard Limited registered Office: Cain Road, Bracknell, Berks RG12 1HN
Registered No: 690597 England
The contents of this message and any attachments to it are confidential and may
be legally privileged. If you have received this message in error, you should
delete it from your system immediately and advise the sender.
To any recipient of this message within HP, unless otherwise stated you should consider
this message and attachments as "HP CONFIDENTIAL".
