The replication_manager is only designed for systems that have yum
installed which means it will always fail on non-RHEL/CentOS systems.
The query threads in mxs1323_stress were not checking whether the test had
ended while they were executing the queries. This caused test timeouts as
the queries can take a relatively long time.
When a backend is waiting for a response but no statement is stored for
the session, the buffer where the stored statement is copied is not
modified. This means that it needs to be initialized to a NULL value.
Added a test that checks that the behavior works as expected even with
persistent connections. A second test reproduces the crash by executing
parallel SET commands while slaves are blocked.
There is still a behavioral problem in readwritesplit. If a session
command is being executed and it fails on a slave, an error is sent to the
client. In this case it would not be necessary to close the session if the
master is still alive.
