As of 950cf6016c, the mediawiki/core repo was updated to use DB_REPLICA
instead of DB_SLAVE, with the old constant left as an alias. This is part
of a string of commits that cleaned up the mixed use of "replica" and
"slave" by sticking to the former. Extensions have not been mass
converted. Please use the new constant in any new code.
The word "replica" is a bit more indicative of a broader range of DB
setups*, is used by a range of large companies**, and is more neutral in
connotations.
Drupal and Django made similar updates (even replacing the word "master"):
*
https://www.drupal.org/node/2275877
*
https://github.com/django/django/pull/2692/files &
https://github.com/django/django/commit/beec05686ccc3bee8461f9a5a02c607a023…
I don't plan on doing anything to DB_MASTER, since it seems fine by itself,
like "master copy", "master tape" or "master key". This is
analogous to a
master RDBMs database. Even multi-master RDBMs systems tend to have a
stronger consistency than classic RDBMs slave servers, and present
themselves as one logical "master" or "authoritative" copy. Even in
it's
personified form, a "master" database can readily be thought of as
analogous to "controller", "governer", "ruler", lead
"officer", or such.**
* clusters using two-phase commit, galera using certification-based
replication, multi-master circular replication, ect...
**
https://en.wikipedia.org/wiki/Master/slave_(technology)#Appropriateness_of_…
***
http://www.merriam-webster.com/dictionary/master?utm_campaign=sd&utm_me…
--
-Aaron