Remove maintenance script fixSlaveDesync.php
Though this script was run on Wikimedia sites years ago (see T8399), there
are enough reasons to doubt it will be run again:
* There is a hardcoded maximum page_id value, which would have to be
changed or removed before reuse.
* It scans the entire page table in a single SELECT query and stores all
values of page_id and page_latest in a PHP array, which might not be
feasible on a large wiki.
* It writes directly to slaves. In contrast, the manual page for
pt-table-sync (from Percona Toolkit) says in general, "[...] it always
makes the changes on the replication master, never the replication slave
directly. This is in general the only safe way to bring a replica back
in sync [...]".
* It only works on the page/revision/text tables. In contrast, pt-table-sync
can work on any table having a primary key.
* It does try to detect whether revisions are missing on the master (instead
of on the slave). However, this won't work because of a bug introduced in
r91243 /
bb1df74f8715 (it actually queries the master twice and puts the
second result set in $slaveIDs).
Change-Id: I85c98821af308abf7dde8068d7cbca17d06b1362