For a long time I had trouble with disconnects, or what looked like disconnects.
I implemented the "disconnect after X period of time inactivity" - whatever "inactivity" consists of (I think I use some of the nettalk webserver counters that Bruce showed me).
Also looked into Rick's solution, which is awesome (but that I couldn't get working, and on zooming with Rick discovered it wasn't going to solve what the root issue looked like).
In the end, what (completely) solved the specific sql connection issues I was facing was upgrading my Clarion 11 to the latest version.
At some point between the version I had and the latest, one or more SQL bugs were squashed that resolved what was plaguing my websever instances.
--
The user story was that they would be working and the system would "Freeze".
On investigation, at a time I was logged in and active, it was clear that there was a threading/connection situation going on, as you could navigate around to some places in the portal, but others would hang.
This along with discussions with Bruce and Rick, led me to upgrade my Clarion - which ended up solving this particular thing.