Hi @Nnaka1, thanks for taking the time to report this! Which exact MediaWiki version is this about?

Hi, @Aklapper, thanks for the reply and hope you're staying healthy! I am currently using MediaWiki 1.34.0. From what I found in other forums, there seemed to be folks who saw this in older versions (<=1.31).

1105 Percona-XtraDB-Cluster prohibits use of GET_LOCK with pxc_strict_mode = ENFORCING

Apparently Percona's fork of MySQL is not fully compatible with MySQL under certain configurations.

@CCicalese_WMF: This is basically the bug that T226857: Provide capability for a DB to be added in an extension was originally filed to try to fix, and the solution here is probably to do T226857: Provide capability for a DB to be added in an extension so something like https://github.com/MWStake/PerconaDB can be used.

This is great! Thanks for the suggestion, @Anomie!

I actually have a similar question to that which appears in https://phabricator.wikimedia.org/T226857 and I want to make sure that I'm fully understanding:
By setting MW_INSTALL_PATH to my mediawiki root with the extension cloned to the extensions directory, composer will "autoload" the extension at MediaWiki install time (i.e. before LocalSettings.php is generated).
And this autoloading will enable for a new "percona" selection at DB selection stage for the web installer.
Is this correct?

Untagging Core Platform. Tracking work for this in T226857.