BadtooManySessions Error

I am strictly using Ignition as an OPC server. So, all that is configured is the devices under the opc ua section. I connect with an inhouse opc client and just issue read/wirte commads to Ignition based on the opc client. Everything has worked fine until recently. We now have 134 devices connected and when we tried to connect we got the BadTooManySessions Error. I got the same error while trying to connect with UAExpert.

After doing nothing eventually the error went away.

What consists of a session in Ignition?
Can I bump it up to above 100?

I am only running 134 devices now, but eventually we will have around 700 for this plant.

We just bumped the memory on a server up to 16 gig because we were hitting the max in Ignition at the 6 gig configured limit. We are going to bump ignition to use 10 gig.

Is this a good idea?

How much memory can I use with Ignition or should I be splitting into multiple ignition servers for the 700 devices?

You can bump up the session limit, at least in 8.1.17+, but you shouldn't need to.

Unless you are connecting 100+ different clients something about your in-house client implementation is broken and probably creating/abandoning sessions, and you'll probably just bump up against whatever higher limit you set.

Thanks Kevin! for the answer. Today, unfortunately every device that is connecting is its own opc client ( how some older code was written). We are building parts down a line and did not want any interference/delay of communication from one machine to another so each one is in its own thread/opc client. We can look at changing this. But it sounds like we for now we will need to play with the session limit. Is it a problem to throw a lot of memory at Ignition or is it better to have multiple ignition servers?

Thanks for your help!

Oy! I'd move that custom code into Ignition.


What does this mean?

You're talking about using Ignition just as an OPC UA server, and typically when you talk about "devices" and the number of devices connected, it's about adding device connections using Ignition's drivers.

Is this not what you meant in the original post?