The PAM conversation function currently throws an error if it encounters any messages that are not PAM_PROMPT_ECHO_OFF or PAM_PROMPT_ECHO_ON:
This means that a user's MaxScale log can fill up with error messages like the following:
If msg_style=4, then it is of the type PAM_TEXT_INFO:
These appear to be harmless messages:
Display some text.
That doesn't really seem worthy of an error that causes the connection to fail.
It seems like it would be better to log PAM_TEXT_INFO messages with MXS_NOTICE or MXS_INFO instead of MXS_ERROR, and then also return PAM_SUCCESS, so it doesn't count as a failure.