[Mageia-webteam] [Mageia-sysadm] Forum VM needs

Sat Jan 15 16:11:59 CET 2011

On Sat, Jan 15, 2011 at 11:46:38AM +0100, Maât wrote:
+> Le 13/01/2011 13:29, Michael Scherer a écrit :
+> 
+> ----8<----
+> > In any case, postgresql to mysql conversion doesn't look doable.
+> >
+> It could be done using things like TOS
+
+Url ? 
+
+> > But we are not ready, see my answer about gitorious. So here is a
+> > proposal in 4 steps :
+> >
+> > Now :
+> > - we do a git checkout every 5 minutes ( just need the url, and
+> > testing )
+> Ouch
+
+Why ouch ?
+
+5 minutes is too often, not often enough ?
+( this is configurable, as this is based on cron )
+
+I would prefer a pull based approach rather than push, because 
+1) this is already written
+2) this is more secure
+ 
+But it may not be good for deployment.
+
+> >>> Do you need modifications in phpBB sources ?
+> >>>
+> >> yes... some coming from (more or less) official patches (called "mods") some coming from ash 
+> >> and i and perhaps other php devs
+> > /me close eyes when reading "(more of less) official patches".
+> >
+> That's the way phpBB people deals with "mods" : authors (not phpBB Team) publish them on the mods 
+> dedicated forum, and you are free to use (or not) them without warranty at all some are widely 
+> used and well known to be stable...
+> 
+> That's why integration and testing stages are so important
+
+Because software distribution is crappy ?
+That's indeed a good reason ( now, do not be asthonished if we joke on php... )
+ 
+> >>> If that's only for configuration files, we can host them on puppet svn
+> >>> and deploy them with puppet.
+> >>>
+> >> if you want to play with puppet for production and having us not touching it with our dirty hands (^^) i'm perfectly ok with 
+> >> that... but i neeed a integration and testing forum with cascaded by git cloning 
+> >> (and i need to sync database of test from production to simulate version migration then cancel and replay as much a i need) 
+> > Could we do it with a master/slave replication without much trouble ?
+> > ( and possibly, one that would automatically recreate the db once it is
+> > dropped )
+> >
+> > Or we can do snapshot using lvm, but I think this can be quite fragile.
+> >
+> Nope... master/slave replication will not fit my needs : i need 2 separate bases. The production i won't play 
+> with it.
+> 
+> For testing : once i updated the code to the new version there can be SQL modifications : new tables, alter tables, 
+> insert or update for rows...
+> 
+> This will be triggered from admin board of phpBB... with a master/slave this would be forbidden or would brake 
+> replication
+
+That's the idea, stop the replication for testing purposes. Hence my note about recreating it once we 
+drop the slave.
+
+We start with a clean db, we replicate.
+Once we want to test the upgrade, we stop replication, we test.
+We drop the db, we resync if needed
+
+Once we finished the test, we drop the tables, and we restart the synchronisation.
+ 
+> But we could perfectly use the last (nightly ,) production backup to populate the test base when i need to go 
+> back to "clean production state"
+
+This requires use to do backup, and so have at least a backup process
+But we can also do it. I just think that replication would be less heavy 
+on IO than dump/reload when needed ( and would be easier to automate ).
+
+I wonder if we could distribute sql dump of the forum on mirror ( like we could for bugs ). I see
+no obvious use for that at the moment, but liberating data can lead to unexpected usages, and would
+be a interesting move ( or a at least, a interesting thought experiment, since there is private messages
+involved, so this would requires cleaning  ) 
+
+-- 
+Michael Scherer
+