Pete Ashdown wrote:
Our SQL server is a 24 core, 32GB, SSD backed server with very light loads. A slowquery log showed nothing of interest, so we started looking in other directions.
What we found is that if the thread pool max_servers > sql num_sql_socks this error will occur. I haven't looked at the code, but I am guessing that it is locking one SQL socket per thread, and if you have more threads than sockets, then you will start seeing this error. We set max_servers and num_sql_socks both to 15 and we haven't seen the error since.
Well, your database was obviously not fast enough to outpace the rate at which FR can put requests into threads :-) IN 3.0 the num_sql_socks is replaced by the more generic "max" option in the connection pool config. In case this is still an issue there for anyone.