db_charmer_connection_proxy and _level were saved in class variables.
Proxy contains the real connections, so they are shared across all
The bug was found because it caused intermittent failures with
cucumber+phantomjs specs. This setup runs a webapp in a thread and runs
the cucumber specs in a different threads and it causes a race
There a case could made for making force_slave_reads thread safe too.
Rails 3.2.9 requires mysql to be ~> 2.8.2, master requires it to be ~>
2.9 and 3-2-stable branch requires it to be ~> 2.8.
Which means that the latest to date mysql version (2.9.0) does not work
with 3.2.9, but works with master and 3-2-stable. This commit add
requirement to the Gemfile.