Provide users a hint that "KILL <process>" is a possible source of connection loss
Summary: Ref T13210. See PHI943. When a query fails due to connection loss we currently suggest "wait_timeout" and "max_allowed_packet", but something KILL'ing us also causes this outcome. Add that as a suggestion.
Test Plan:
KILL'd a lock three times, got:
$ php -f lock.php [2018-10-24 10:40:29] EXCEPTION: (AphrontConnectionLostQueryException) #2006: MySQL server has gone away This error may occur if your configured MySQL "wait_timeout" or "max_allowed_packet" values are too small. This may also indicate that something used the MySQL "KILL <process>" command to kill the connection running the query. at [<phutil>/src/aphront/storage/connection/mysql/AphrontBaseMySQLDatabaseConnection.php:304] ...
Reviewers: amckinley
Reviewed By: amckinley
Maniphest Tasks: T13210
Differential Revision: https://secure.phabricator.com/D19756