I was curious what information MariaDB’s “phone home” user feedback plugin sends. (It works on more than just MariaDB, by the way.)
It’s easy enough to find out: just load the plugin, then select from the INFORMATION_SCHEMA.FEEDBACK table. This returns a lot of rows that are obviously the status counters and variables, as well as the plugins loaded in the server. A quick exclusion join will eliminate those, and the result on my laptop is this:
This is to follow up my previous post with kernel_mutex problem.
First, I may have an explanation why the performance degrades to significantly and why innodb_sync_spin_loops may fix it.
Second, if that is correct ( or not, but we can try anyway), than playing with innodb_thread_concurrency also may help. So I ran some benchmarks with innodb_thread_concurrency.
Problem with kernel_mutex in MySQL 5.1 and MySQL 5.5 is known: Bug report. In fact in MySQL 5.6 there are some fixes that suppose to provide a solution, but MySQL 5.6 yet has long way ahead before production, and it is also not clear if the problem is really fixed.
Meantime the problem with kernel_mutex is raising, I had three customer problems related to performance drops during the last month.
So what can be done there ? Let’s run some benchmarks.
It's that time of the year where MySQL would be speakers are called to action. As usual, the main event is the MySQL spring conference, this year hosted by Percona. The call for participation to the MySQL Conference And Expo 2012 is still open until December 5th. To submit a proposal, you should register as a speaker and then fill in the form.