ImageServer and UV make sessions lost and 404 errors

Hello can someone give advice how to Debug this?

Lately I have an OmekaS site running with module ImageServer and Unversal Viewer and use tiling with it. Things work fine when zooming slowly, in the UV, but when you do it faster, so that a burst of tile requests is generated, there appear a lot of 404 errors and your sessions get lost (have to login again when going to other page)!

Surely the server is somehow “overloaded” then, (too many db connections?) but how should I debug this? And how to solve it? It had already contact with the hoster, but we cannot see (via the CPanel tools) what could be going wrong.
The Omeka logs only give at some moment (sometimes) the “too many db” connections." An indication I guess :slight_smile: It is standard configured (152 or so?)
It happens with a single user and the UV page is the only thing active at the time, so it is rather dramatic. Anyhow the burst is not more than max a couple of hundred GET requests, so Omeka should be able to cope with that I hope.

On other (local)server, with different db setup, the same Omeka S setup works ok.

Has anybody an idea how to tackle this?

John

P.S. After checking the logs again, its seems clearly the PDO Exception “too many connections” that gives the problem. But how to prevent/solve this?