Symptoms
After receiving errors from a SQL server, which causes the server to close the connection, the monitor (client) tries to continue to use the cached database connection that is no longer valid.
Impact
Monitor marks pool member down when it may not be down.
Conditions
Under certain rare conditions, when a database monitor is unable to connect repeatedly (locked out for too many failed passwords, for example), the database monitor may get into a state where it becomes unresponsive and stop trying to send monitor probes.
Workaround
To work around this issue, you can change the count setting of the affected MySQL or MSSQL monitor to a non-zero value that specifies the number of monitor probes to be sent per connection to the database. A count value of zero (0), which is the default value, indicates the BIG-IP system will leave a single connection open to send probes.
Fix Information
This release contains a fix for the intermittent hang of SQL monitors when cached database connections are closed on the server.
