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Can the Callback enqueuer overflow capacity be increased?

15 Nov 2023 16:04 #12371 by support

The capacity can be changed by setting the CallbackQueueCapacity property of the EasyUAClient object. It must be done before any OPC operation is invoked, otherwise it will have no effect.

The error indicates that the OPC UA notifications are coming in with faster rate than your code is able to process. For example, if there is a steady stream of notifications (events or callbacks) with average period 10 milliseconds, but your code takes 20 milliseconds to process each notification, the queue will grow and grow and eventually fill up, which is what the error is indicating.

The default setting (100000 notifications) makes room for quite a big "lag" in your processing already. Unless the problem is in a short-time peak (that would eventually be consumed and processed), increasing the capacity will just delay the occurrence of the error, but will not resolve the problem.

Best regards

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15 Nov 2023 14:37 #12370 by jgonzalez
Hello team,

I have a customer that is using 2022.1 and is getting the following error:

"OpcLabs.EventTracing.LogEntry("OPCLabs-EasyUAClient",Error,0,1101) Callback enqueuer overflow. The bounded queue capacity is 100000."

We are still trying to figure out the cause and the calls that resulting in this outcome, but I would like to confirm the following:

Can the Callback enqueuer capacity be changed (increased)? from my understanding this is an infrastructure parameter that can not be changed but would just like to confirm my understanding.

Thank you in advance. '

Please let me know if you require additional information.

Best regards.

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