Description:
You've probably noted warnings like these:
2014-02-24 16:32:09 13734 [Warning] Buffered warning: Changed limits: max_open_f
iles: 1024 (requested 5010)
2014-02-24 16:32:09 13734 [Warning] Buffered warning: Changed limits: max_connec
tions: 214 (requested 1000)
2014-02-24 16:32:09 13734 [Warning] Buffered warning: Changed limits: table_cach
e: 400 (requested 2000)
that server outputs when ulimit -n setting is too low and it tries to "autosize" open_files_limit and other related variables accordingly.
The problem is that along with real server variable, max_connections, these warnings mention non-existing ones that nobody actually set or can set in 5.6, max_open_files (probably open_files_limit is meant) and table_cache (probably table_o0pen_cache is meant).
This may cause confusion for users, when they try to change values to get rid of these warnings.
How to repeat:
Make sure that ulimit -n outputs 1024 and then try to start server with all defaults, but max_connections=1000, like this:
bin/mysqld_safe --no-defaults --max_connections=1000 &
Note that max_connections is actually set to 214 only and then check error log trying to find out what's going on.
Suggested fix:
Output names of real server variable auto-adjusted based on low umilit -n setting.
Optionally, add warning with a hit about the reason (low ulimit -n setting).