[Gluster-users] Database clustering in Gluster
freedman at FreeFormIT.com
Tue Aug 5 18:07:26 UTC 2008
At 05:37 AM 8/4/2008, Bobirkhon Ismailov wrote:
>Right now I'd like to try AFR feature of Gluster (ver. 1.3.10) by
>using it with database files (Postgresql).
>In examples/afr.vol file the following feature is on:
> type features/posix-locks
> option mandatory on # enables mandatory locking on all files
> subvolumes posix1
>My question is, how critical is locking for database clustering+AFR
>and is there information about
>using/configuring Gluster for database clastering in general?
my guess is, if you're only going to be writing to the database at
one location, locking probably isn't as important. you should
enable locks on that machine I'm guessing, but they may not need to
The devels can shed more light on the exact process, but I'm thinking
you may run into some troubles with AFR for such large files.
It's not clear to me how the auto-heal works exactl.
IF you get disconnected, and one of the servers tries to auto-heal
the database file, Does it just move over the diffs, which is a fast
operation, or does it copy over the entire file. If it's the latter,
this could become quite a problem.
If you're going to be writing the db files at multiple locations YOU
MUST enable locking and it MUST be mandatory.
I've not personally experienced this, but I've heard of it working ok
with mysql -- which had to be explicitly set to use external locks
and it worked ok, but I think the ramifications of
split-brain/auto-heal are pretty severe in a multi-write database environment.
those are my thoughts.
>Thank you very much,
>Gluster-users mailing list
>Gluster-users at gluster.org
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