Hello! 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: volume brick1 type features/posix-locks option mandatory on # enables mandatory locking on all files subvolumes posix1 end-volume My question is, how critical is locking for database clustering+AFR and is there information about using/configuring Gluster for database clastering in general? Thank you very much, Bobir -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://supercolony.gluster.org/pipermail/gluster-users/attachments/20080804/9c3090b5/attachment.html>
At 05:37 AM 8/4/2008, Bobirkhon Ismailov wrote:>Hello! > >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: > >volume brick1 > type features/posix-locks > option mandatory on # enables mandatory locking on all files > subvolumes posix1 >end-volume > >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 be mandatory. 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, > >Bobir >_______________________________________________ >Gluster-users mailing list >Gluster-users at gluster.org >http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users
At 05:37 AM 8/4/2008, Bobirkhon Ismailov wrote:>Hello! > >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: > >volume brick1 > type features/posix-locks > option mandatory on # enables mandatory locking on all files > subvolumes posix1 >end-volume > >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 be mandatory. 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, > >Bobir >_______________________________________________ >Gluster-users mailing list >Gluster-users at gluster.org >http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users
At 05:37 AM 8/4/2008, Bobirkhon Ismailov wrote:>Hello! > >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: > >volume brick1 > type features/posix-locks > option mandatory on # enables mandatory locking on all files > subvolumes posix1 >end-volume > >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 be mandatory. 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, > >Bobir >_______________________________________________ >Gluster-users mailing list >Gluster-users at gluster.org >http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users
At 05:37 AM 8/4/2008, Bobirkhon Ismailov wrote:>Hello! > >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: > >volume brick1 > type features/posix-locks > option mandatory on # enables mandatory locking on all files > subvolumes posix1 >end-volume > >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 be mandatory. 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, > >Bobir >_______________________________________________ >Gluster-users mailing list >Gluster-users at gluster.org >http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users