[Labs-l] Labs datacenter migration

[Andrew Bogott]

     Almost a year ago, the Wikimedia Foundation migrated most of our 
services from our old data center in Tampa to the new one in Ashburn 
[1].  In the next couple of months Labs and Tool Labs will be following 
suit -- we expect to have everything moved to Ashburn by mid-January at 
the latest.

     This move will provide some immediate benefits (lower latency with 
production, quicker database replication) and many long-term benefits 
(better stability, happier Operations staff).  We don't yet have a 
specific timeline for stages of the migration, but there are a few 
things you can do now to help us prepare for the change and to bolster 
your projects against possible disruption.

1)  Subscribe to Labs-l, and read it. [2]  Labs-l is low-volume, and 
future migration announcements may not be sent to other lists.

2)  Tool Labs users:  As long as your tools are properly managed by the 
grid engine and can survive stops and restarts, the migration will be 
quite painless.  If your tools aren't, or can't... fix them :)

3)  Labs project admins:  Clean up old projects and instances.  If you 
have instances that are no longer of interest, delete them.  If you know 
of entire projects that are no longer in use, please contact me directly 
and I'll mop up.

4)  Labs instance owners:  Make sure that puppet is running properly on 
your instances.  If '$sudo puppetd -tv' produces any red lines, then fix 
them or contact me for help with fixing.  When instances move to the new 
data center we'll be relying on puppet to update location-specific 
settings, so instances without puppet may not survive the move.  If your 
instance uses self-hosting puppet (via puppetmaster::self or 
role::puppet::self) then you will also need to update your local puppet 
repo. [3]

5)  All Labs users: if you have valuable data residing on local instance 
storage, start backing it up to shared storage in /data/project.  You 
should be doing this anyway -- no instance is safe from catastrophe, ever.

6)  If your project or tool generates log files, have a look at purging 
old log data.  The last time we did a data migration there was at least 
one terabyte-sized logfile that really gummed up the works.


     Updates about this change will be posted to this list as soon as we 
know about them.  Any potential downtime will be announced well in 
advance.  In the meantime, don't hesitate to ask questions about the 
above steps on IRC or the mailing list.

-Andrew


[1] 
https://blog.wikimedia.org/2013/01/19/wikimedia-sites-move-to-primary-data-center-in-ashburn-virginia/

[2] https://lists.wikimedia.org/mailman/listinfo/labs-l

[3] https://wikitech.wikimedia.org/wiki/Help:Self-hosted_puppetmaster#FAQ