[Mageia-dev] Replacing mysql with mariadb

Thu Dec 1 21:12:57 CET 2011

'Twas brillig, and Maarten Vanraes at 01/12/11 19:53 did gyre and gimble:
+> Op donderdag 01 december 2011 10:32:14 schreef Colin Guthrie:
+>> 'Twas brillig, and Maarten Vanraes at 01/12/11 08:05 did gyre and gimble:
+>>> The way I see it, there are 2 possibilities:
+>>> A. I remove the mysql-client, libmysqlclient, mysql-common and assorted
+>>> packages from mysql, and provide them with mariadb, since libmysqlclient
+>>> is drop-in replacable (same library ABI and such), there is not 100%
+>>> requirement of rebuilding all libmysqlclient dependant programs.
+>>
+>> I think that rather than just provide them, it would make sense to use
+>> the update-alternatives system.
+>>
+>> It's going to be quite hard to rip out one package and drop in the other
+>> without some problems so it would be nice if we could install both at
+>> the same time and switch between them with a simple update-alternatives
+>> plan. This would perhaps facilitate easier testing too (i.e. easy to
+>> compare one to the other and switch about etc.)
+>>
+>> In the initial stages you can make MariaDB have a higher priority in the
+>> update-alternatives setup to encourage more usage/testing coverage.
+>>
+>> While I appreciate it's extra effort for you and QA, I think this is the
+>> best route forward for mga2 at least.
+>>
+>> Col
+> 
+> i don't think the update-alternative is usable for the client parts at least
+> 
+> you will need to build programs with mariadb mysqlclient.so, so that doesn't 
+> work as alternatives, so that means the whole common and mariadb client is 
+> required too
+
+Hmm, I'm not sure I understand why it doesn't work? Why can't
+mysqlclient.so itself be a symlink via alternatives? Does the linker
+bork perhaps?
+
+If both packages provide the same virtual provides ("mysql-devel") then
+it should be pretty simple to make the one provided by mariadb to be the
+preferred one (not 100% sure how that works, but I think it's possible).
+
+> so the only thing that can be alternativified would be the server, which is not 
+> really necessary to be alternivified anyway, since you can just install mariadb 
+> for that and remove mysql.
+> 
+> you have to remember how mariadb works, it's like us, they take mysql from 
+> upstream, and put patches on it.
+> 
+> the client doesn't have any major feature changes, it just has some 
+> improvements for if you'd use mariadb and some bugfixes. ( mariadb server with 
+> mysql client, works also perfectly, allthough NOT on the same server, due to 
+> my.cnf )
+> 
+> but however you look at it, client and common part of mysql will need to be 
+> obsoleted.
+
+Thinking about all the issues, it will be pretty complicated to fully
+alternativify it (all the conf files etc. would be a bit of a pain)
+
+Not sure how to handle it, but I don't think obsoleting the existing
+mysql packages is a great idea... I guess just another round of testing
+after it hits the main repo might be enough? Can you just make the
+package provide the same things as the mysql ones but with a higher
+release number? That's how the systemd-sysvinit package was forced on
+people over sysvinit... perhaps the same approach here would force some
+testing and to revert all we need to do is bump the mysql rel up two
+notches and it'll become the default again?
+
+Col
+
+
+-- 
+
+Colin Guthrie
+colin(at)mageia.org
+http://colin.guthr.ie/
+
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