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

[Petr Bena]

Keeping debug symbols in binaries will result in poor performance, or it
should


On Thu, Feb 14, 2013 at 4:47 PM, Asher Feldman <afeldman at wikimedia.org>wrote:

> For most projects, I recommend using the official packages available via
> the MariaDB projects own apt repo.
>
> The official packages are based on the Debian mysql packaging where
> installing the server package also installs a default database created
> around generic config defaults, a debian mysql maintenance user with a
> randomly generated password, and scripts (including init) that assume
> privileged access via that user. That is, installing the packages provides
> you with a fresh running working database with generic defaults suitable
> for a small server, and certain admin tasks automated. I think that's what
> the average labs and general users wants and expects.
>
> The packages I've built for production use at wmf strips out all of the
> debianisms, the debian project script rewrites, the pre/post install
> actions. They also leave debug symbols in the binaries and have compiler
> flag tweaks, but do not at this stage contain any source
> patches. Installing the server package doesn't create a default db, or
> provide an environment where you can even start the server on a fresh sever
> install without further work. Probably not a good choice for most labs
> users.
>
> On Wednesday, February 13, 2013, Petr Bena wrote:
>
> > 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<javascript:_e({},
> 'cvml', '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<javascript:_e({},
> 'cvml', '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<javascript:_e({},
> 'cvml', 'innocentkiller at gmail.com');>>
> >> wrote:
> >> >
> >> >> On Wed, Feb 13, 2013 at 8:05 AM, bawolff <bawolff+wn at gmail.com<javascript:_e({},
> 'cvml', 'bawolff%2Bwn 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
> >> >>
> >> >> _______________________________________________
> >> >> Wikitech-l mailing list
> >> >> Wikitech-l at lists.wikimedia.org <javascript:_e({}, 'cvml',
> >> 'Wikitech-l at lists.wikimedia.org');>
> >> >> https://lists.wikimedia.org/mailman/listinfo/wikitech-l
> >> >>
> >> >
> >> >
> >> > _______________________________________________
> >> > Labs-l mailing list
> >> > Labs-l at lists.wikimedia.org <javascript:_e({}, 'cvml',
> >> 'Labs-l at lists.wikimedia.org');>
> >> > https://lists.wikimedia.org/mailman/listinfo/labs-l
> >> >
> >> >
> >> _______________________________________________
> >> Wikitech-l mailing list
> >> Wikitech-l at lists.wikimedia.org <javascript:_e({}, 'cvml',
> >> 'Wikitech-l at lists.wikimedia.org');>
> >> https://lists.wikimedia.org/mailman/listinfo/wikitech-l
> >>
> >
> >
> _______________________________________________
> Wikitech-l mailing list
> Wikitech-l at lists.wikimedia.org
> https://lists.wikimedia.org/mailman/listinfo/wikitech-l
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.wikimedia.org/pipermail/labs-l/attachments/20130214/fd6044f0/attachment-0001.html>