[Labs-l] Upgrading labs db replicas to MariaDB 10

[Sean Pringle]

An update:

The first MariaDB 10 instance replicating all shards will be ready shortly,
after it finishes importing wikis and the seven replication channels catch
up. The tentative switch-over time is around 2014-07-24 02:00:00 UTC.

We plan to switch s2, s4, and s5 first.which are on the same backend host,
labsdb1002. This will involve:

1. Downtime ~30m, during which tool connections may fail for these host
names:

bgwiki.labsdb
bgwiktionary.labsdb
cswiki.labsdb
commonswiki.labsdb
dewiki.labsdb
enwikiquote.labsdb
enwiktionary.labsdb
eowiki.labsdb
fiwiki.labsdb
idwiki.labsdb
itwiki.labsdb
nlwiki.labsdb
nowiki.labsdb
plwiki.labsdb
ptwiki.labsdb
svwiki.labsdb
thwiki.labsdb
trwiki.labsdb
wikidatawiki.labsdb
zhwiki.labsdb

2. Several hours of read-only access to upstream wikis for those host
names, while labs user data is migrated across. We have to impose this for
data consistency.

3. Several more hours during which slow traffic may be throttled or killed,
while caches warm up and we verify that the whole plan was, in fact, sane.

BR
Sean
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.wikimedia.org/pipermail/labs-l/attachments/20140722/63bea8a8/attachment.html>