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  5. QuickOPC-Classic in .NET
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  9. Connecting to many OPC-servers using multiple threads gives Timeouts

Connecting to many OPC-servers using multiple threads gives Timeouts

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02 Sep 2020 09:39 #8825 by zaglerp
Replied by zaglerp on topic Connecting to many OPC-servers using multiple threads gives Timeouts
Hello,

thank you, I tried your suggestions.
If I request all nodes using a single call it takes approx 50 seconds and some servers have a timeout.

Why do I get timeouts here? All servers are up and running.
And when requested sequentially everything is working fine...

Kind regards
Peter

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02 Sep 2020 09:22 #8824 by support
Replied by support on topic Connecting to many OPC-servers using multiple threads gives Timeouts
Hello,
I am not sure about the behaviors you have described, that would require more investigation, but none of them is the one we recommend.

The recommended approach is to call a single MultipleRead with all the target OPC servers, and let QuickOPC sort out the rest.

Best regards

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02 Sep 2020 07:58 #8822 by zaglerp
Connecting to many OPC-servers using multiple threads gives Timeouts was created by zaglerp
Hello,

I try to do a MultipleRead (with 19 values) from 30 OPC-Servers running on 30 different hosts. THese servers are all up and running.
The behaviour is unclear to me:

1. Using 30 C#-Tasks running in parallel:
The whole process completes after approx. 51 seconds. At least one OPC-Server returns a timeout error (BadRequestTimeout)

2. Using 30 C#-Tasks running in sequence (using a lock):
The whole process completes after approx. 41 seconds until all Reads are completed. All OPC-server are working - no timeouts.

Can you please clarify, why
- it is faster to do this in sequence than in parallel
- some Servers have a timeout when accessed in parallel

Which procedure to you suggest for implementing this?
I have attached my test program, written in C# and using 5.58.257.1
Line 54 contains a lock that was commented out for parallel access.

Thank you for your support.
Peter
Attachments:

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  1. Forum
  3. Discussions
  5. QuickOPC-Classic in .NET
  7. Connections, Reconnections, COM/DCOM
  9. Connecting to many OPC-servers using multiple threads gives Timeouts
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