OPC UA Server

[Vslav]

Hello, I have a temporary problem with OPC UA server on my CtrlXCore. I use OPC UA Server  version 1.20 . Connect to it with OPC UA Client based on Node-Red on another PC, without additional security, only authentification. It works well for 1-2 days and after that I recieve an error x800300000 "Server Out of memory" and have following statistics on server? What  could cause such behaviour? Number of subscriptions looks unreal. Config of server and screenshot in attachment. many thanks for any comments.

[Sgilk]

Hello,
Could you please post your Node-RED flow? I suspect you are frequently triggering subscriptions to the OPC UA server in your client implementation.

[Vslav]

Hello, Yes, sure

I use this 2 flows to communicate with control. Only clim.txt have subscriptions (in 5 nodes), other one  - only writes variables. Made .txt because cannot load .json. For 36 to 48 hours statistics do not change at all and works well. But each 2nd- day , ususlly at night  it reches following numbers.   Also this control sometimes loses its PLC App License, but I guess its a separate topic.

[Sgilk]

I believe this is your issue. A lot of your inject nodes are set to repeat at an interval. This will create duplicate subscriptions to the OPC UA server endpoints.

[Vslav]

Hello,

Repeat injection uses only for write nodes, and made for forcing KNX/IP reading once in 20m, subscription nodes does not have repeat injection.  In addition , injection  once in 20 min will not give more than 400 million subbscription in two days. Just checked today once more this number changes in seconds from 15 to 400 millions after recieveng error x80030000 on Node-Red server.

[Sgilk]

Could you please post a screenshot of your Settings-->Information-->Resources page when the error has occured? 

[NoRisk4Project]

Hello,
in addition to Sgilk's request for the flows, could you also provide a WireShark trace?
I'm in contact with development an we want to examine the behavior.
We think the current subscription count of 4.294.967.293 reaches a limit inside the server. We want to fix this, so the server will keep running, even if a client creates such a very high amount of subscriptions.

[Vslav]

Here is the screen shots. one thing i checked more is that after "Current subscription count" gets its limit " reject session count" starts also grow realy intence. +5 or +10 sessions per second, but node red has a timer, in case of bad connection it start reconnect only after 30 seconds. For wireshark trace   needs dome time for check.

[Vslav]

Hello, please find attached  wireshark trace for opc ua server . 172.16.131.27 - CtrlX Core, 172.16.131.210 - PC with Clim.txt flow, 172.16.131.211 - PC with blinds.txt flow.  Only .txt file was possible to attach.

[NoRisk4Project]

Hello,

unfortunately, the txt file is not very helpful. Please zip the Wireshark (if it's smaller than 200 MB) or send it to me via email, so I can take a look at it.

[Vslav]

Please find attached zip file

[NoRisk4Project]

Hello,

we checked both traces and we don't see a reason for this high number inside the "Current subscription count" of 4.294.967.293. Not within 36 to 48 hours. I'm in contact with development to discuss the error and to find the reason for this behavior.

To prove our theory, can you please send us a screenshot, similar to "image_2023-12-13_10-36-22.png", but before the error occurs. The "Current subscription count" should be around 1 or switch between 0 and 1.

[Vslav]

Hello,

please find attached screenshot of OPC UA Server status before error. Rejected sessions are rejected by timeout, I guess.

[Vslav]

@NoRisk4Project  is there any news?

[NoRisk4Project · Accepted solution]

Hello,

We found the reason for the problem, it's a bug inside the OPC UA SDK we use for our server. A bug report was send to our SDK provider and we received yesterday the bugfix. The bug will be fixed with the upcoming version 2.6 (RM24.03) of the ctrlX AUTOMATION - OPC UA Server app.

[Vslav]

Hello, Could you please send link to new version of OPC UA Server App. Could not find it in collaboration room.

[CodeShepherd]

The version 2.6 is still in early adopter state; so you need to ask for getting access to this area. See "FAQ for ctrlX Store".

Free for sales and download the new version will be in July this year. See also "Release cycle of apps and engineering software".