Something slows everything down

[GurcanBicer]

Type of issue

• Bug
• Enhancement
• Compliance
• Question
• Help wanted

Current Behavior

I need help with a problem.
The application is supposed to run 24/7-365 days.
Now and then, the memory usage increases, and the messages become so slow from OPC.UA.
I just got a memory dump before restarting the application.

For some reason, the subscription's IncomingMessages list has become huge. It looks like a circular referencing is happening here.

What would be the reason for this, could you please help me?

Expected Behavior

No response

Steps To Reproduce

No response

Environment

- OS:Windows Server 2022
- Environment:Visual Studio 2022
- Runtime:.NET 4.8
- Nuget Version: 1.4.372.106
- Component: Opc.Ua.Core
- Server: Kepware
- Client: Custom Built

Anything else?

No response

[EthanChangAED]

Hello @GurcanBicer, thank you for reporting this. I noticed that you are using an earlier version of the stack. As we recently made several performance improvements, I would suggest you try with the latest release. Or wait for the April release (ETA mid-March) that would also include one more bug fixing.

[mregen]

The incoming message list size can be configured using MaxMessageCount. Could you check the setting?

[GurcanBicer]

@mregen , I will try that.

The sampling rate is 250ms, and the publishing interval is 250ms.

There is only 20-25 monitored items on that subscription. And those PLC tags doesn't generate that much of a data. But if that list grows even without a value change, it is still possible, if the publishing interrupted for some reason. But I don't see any log messages regarding a publish problem.

I will upgrade the library version next week and monitor for a while.