Hello!
As I have commented on some tickets, MariaDB 10.1 will reach its
end-of-life 17th October 2020 (
https://mariadb.com/wp-content/uploads/2019/07/mariadb-engineering-policies…
).
Debian Buster doesn't ship 10.1, but 10.4. We have been testing 10.4 in
production for quite some time already (
https://phabricator.wikimedia.org/T242702
https://phabricator.wikimedia.org/T246604)
We have filed some bugs, but nothing super worrying have been observed in
production (bugs:
https://jira.mariadb.org/browse/MDEV-21794
https://jira.mariadb.org/browse/MDEV-21813
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=953040)
A few weeks ago, during some Wikidata overloads, we observed that the host
with Buster and 10.4 performed better, CPU wise, than the ones running 10.1
and Stretch with InnoDB compression, having the same hardware. We haven't
found 100% why, but we believe that 10.4 might have some optimizations.
Given that there've been some Quarry reports about being slow (
https://phabricator.wikimedia.org/T246970
https://phabricator.wikimedia.org/T247978)
Considering the fact that Quarry points to labsdb1011, and in order to
discard a specific issue with that host we thought about replacing
labsdb1011 with another host (
https://phabricator.wikimedia.org/T247978#5980018) but maybe we can just
try to upgrade labsdb1011 to buster and 10.4
So far we have had normal 1 instance hosts upgraded, multi-instance (2
mysqld processes) upgraded, and we need to have a multisource (labsdb) host
upgrade, to make sure 10.4 works fine or to know what might need work
(mysqld-exporter
https://phabricator.wikimedia.org/T247290 or whatever),
better to know in advance.
10.4 also fixes some bugs that are hitting labsdb hosts specifically:
- Grants race condition:
https://jira.mariadb.org/browse/MDEV-14732
- GTID works on multisource:
https://jira.mariadb.org/browse/MDEV-12012 this
is one of the early bugs we filed with MariaDB almost 3 years ago and looks
like it is now working even though - this requires some work on the
master's side, but my last tests are looking good and if we can enable GTID
on labsdb hosts that'd we be a BIG improvement towards avoiding corruption
during a crash.
So, any objections to reimage labsdb1011 as Buster and 10.4 (/srv won't be
formatted, so we don't have to rebuild that host).
Cheers
Manuel.