MySQL memory usage issues?
MySQL Community Manager Morgan Tocker posted a blog earlier this year on how to reduce memory consumption in MySQL.

http://www.tocker.ca/2014/03/10/configuring-mysql-to-use-minimal-memory.html

Some of the settings he uses are not really realistic for a production instance of MySQL, because the settings are far below what it takes to give good performance. But his blog was an exercise, not a recommendation. Anyway, it can show you many of the settings that do have an effect on memory use.

Your server with only 2GB of RAM is pretty undersized for a MySQL server. Consider this survey of MySQL users, asking how much RAM they have in their servers. The top answers were 16-64 GB and 4-16 GB.

http://www.mysqlperformanceblog.com/2012/11/02/how-much-memory-do-you-use-to-run-mysql/