Thanks Hartmut for having brougth this up. Comments inline. Cheers, JFG On 9 February 2017 at 11:42, Hartmut Holzgraefe <hartmut@mariadb.com> wrote:
In MariaDB 10.1 binary packages several storage engines, e.g BLACKHOLE and ARCHIVE, are no longer compiled in by default but only come as loadable plugins that need to be loaded into the server explicitly.
This is mentioned on the knowledge base pages for these engines, e.g. https://mariadb.com/kb/en/mariadb/blackhole/ and https://mariadb.com/kb/en/mariadb/archive/ but is not mentioned in the release notes and the detailed changelog pages for 10.1.x releases at all.
I also searched my "maria-developers" and "maria-discuss" mail archives but could not find any discussion or announcement on this topic either. Same for Jira, can't find any ticket that would describe that sort of change there either.
My understanding of above boils down to the 3 questions below: - was that a conscious change, - what were the reasons for that change, - do people agree with that change. If it was not done on purpose and there is no valid reasons to do the change, it should probably be considered as a bug and fixed. [1] is opened to have mysql_upgrade handle the situation, maybe we should also open a but to add back blackhole enabled by default (I am less sure about ARCHIVE and FEDERATED). [1]: https://jira.mariadb.org/browse/MDEV-11942 Does anyone here have an opinion on this ? Do you agree (or disagree) that blackhole should not enabled by default ? My opinion on that below. Problems with the current situation:
* comes as a surprise for installation using these storage engines when upgraded to 10.1
I confirm this is a surprise, and I was actually bitten by that.
* mysql_upgrade should handle this, but doesn't: https://jira.mariadb.org/browse/MDEV-11942
I have no strong opinion about keeping blackhole disabled by default or re-enabling it. However, if blackhole stays disable by default, I think mysql_upgrade MUST handle the situation. More opinion below.
* it is not even easily possible to identify affected tables after an upgrade to 10.1. For BLACKHOLE tables I_S.TABLES only shows these under specific conditions, and for ARCHIVE it seems to be impossible to identify affected tables at all if the plugin is not loaded https://jira.mariadb.org/browse/MDEV-11943
If we cannot, in the next 2 minor version releases, make mysql_upgrade handle that case, I think blackhole should be re-enabled. The motivation for that is that we should maintain an upgrade story, and if a user it using blackhole in 10.0, it should work after an upgrade. I have submitted a a fix for MDEV-11942, but without
having a fix for MDEV-11943 it only works for BLACKHOLE so far, not for ARCHIVE (haven't tested FEDERATED or other potentially affected engines yet). https://github.com/MariaDB/server/pull/304
Thanks again Hartmut for having brought this up on the mailing list. Best regards, Jean-François Gagné System Engineer Booking.com B.V. Vijzelstraat 66-80 Amsterdam 1017HL Netherlands