On 26.1.2012, at 18.06, Ed W wrote:
Could it be a *timeout* rather than lack of worker processes?
The message in log was "Unknown user". The only reason this happens is if MySQL library's query functions returned success without any rows. No timeouts, crashes, or anything else can give that error message. So I'd the problem is either in MySQL library or MySQL server.
Try if the attached patch gives any crashes. If it does, it means that mysql library returned mysql_errno()=0 (success) even though it should have returned a failure. Or you could even change it to only:
i_assert(result->result != NULL);
if you're not using MySQL for anything else than auth. The other possibility is if in driver_mysql_result_next_row() the mysql_fetch_row() returns NULL, but also there I'm checking mysql_errno().