[Labs-l] [Wikitech-l] Maria DB

[Petr Bena]

thanks for updates.

Can you tell me what is a difference between maria db you are using and the
version that is recommended for use on ubuntu?


On Wed, Feb 13, 2013 at 6:58 PM, Asher Feldman <afeldman at wikimedia.org>wrote:

> The production migration to MariaDB was paused for a time by the EQIAD
> datacenter migration and issues involving other projects that took up my
> time, but the trial production roll-out will resume this month.  All signs
> still point to our using it in production.
>
> I did a lot of query testing on an enwiki MariaDB 5.5 slave over the course
> of more than a month before the first production deployment.  Major version
> migrations with mysql and derivatives are not to be taken lightly in
> production environments.  At a minimum, one must be concerned about query
> optimizer changes making one particular query type significantly slower.
> In the case of the switch to 5.5, there are several default behavior
> changes over 5.1 that can break applications or change results.  Hence,
> some serious work over a plodding time frame before that first production
> slave switch.
>
> Despite those efforts, a couple weeks after the switch, I saw a query
> generated by what seems to be a very rare edge case from that AFTv4
> extension that violated stricter enforcement of unsigned integer types in
> 5.5, breaking replication and requiring one off rewriting and execution of
> the query locally to ensure data consistency before skipping over it.  I
> opened a bug, Mathias fixed the extension, and I haven't seen any other
> compatibility issues from AFTv4 or anything else deployed on enwiki.
>
> That said, other projects utilize different extensions, so all of my
> testing that has gone into enwiki cannot be assumed to fully cover
> everything else.  Because of that, and because I want to continue
> proceeding with caution for all of our projects, this will continue to be a
> slow and methodical process at this stage.  Bugs in extensions that aren't
> used by English Wikipedia may be found and require fixing along the way.
>
> As the MariaDB roll-out proceeds, I will provide updates on wikitech-l.
>
> Best,
> Asher
>
> On Wed, Feb 13, 2013 at 5:19 AM, Petr Bena <benapetr at gmail.com> wrote:
>
> > Okay - so what is outcome? Should we migrate beta cluster? Are we going
> to
> > use it in production?
> >
> >
> > On Wed, Feb 13, 2013 at 2:08 PM, Chad <innocentkiller at gmail.com> wrote:
> >
> >> On Wed, Feb 13, 2013 at 8:05 AM, bawolff <bawolff+wn at gmail.com> wrote:
> >> > Umm there was a thread several months ago about how it is used on
> >> several
> >> > of the slave dbs, if I recall.
> >> >
> >>
> >> Indeed, you're looking for "mariadb 5.5 in production for english
> >> wikipedia"
> >>
> >> http://www.gossamer-threads.com/lists/wiki/wikitech/319925
> >>
> >> -Chad
> >>
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