Hello,

Using Firebird 2.1.1.17910 (windows 32 bits), classic mode (fb_inet_server.exe), do we have a known limit to the number of simultaneous connections that can be opened (count of subprocesses for instance)? What I'm talking about is a server handling connections to a large number of different databases, so we're not talking of let's say 400 connections to a same DB, but maybe 400 connections to different DBs with never more than 10 to 20 attachments to a same DB, and often only 1 or 2 (say 400 attachments distributed on 300 DBs).

There is no performance issue nor hardware resource exhaustion of any kind, the live test runs nicely for months, all application processes do recycle themselves once every 24h, closing all attachments, even the fb_inet_server service is cycled once per 24 hour, yet, rarely (once every some weeks), but when playing in the > 300 attachments range (could be 350 or 400, does not seem precise), I have seen new attachments denied (-904, code 335544375) and this logged in firebird log:

XNET error: Server failed to respond on connect request

What kind of limitation could this be?

That's nothing critical, load has been spread over multiple VMs on the same HW machine, demonstrating it is not a hardware resource limitation, it just doesn't feel 'right'. ;)

Thanks for ideas or questions you might have,
Sincerely,

—
Olivier Mascia