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I'm still having problem when reconnecting to opc da servers. The opc library is stuck somewhere.
It's only solved by restarting my application.
QuickOPC build 5.56.1073.1
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I removed my "opc server stuck" detection logic and upgraded opc library to version 5.56.1055.1.
It still does not work. It looks like we have a similar problem.
Can you investigate opc threads call stacks?
I'm planing to upgrade opc library to last available version 5.56.1073 and add "opc server stuck" detection logic.
Regards
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I have updated the opc library to the version 5.56.1055.1. It should run several days to be sure that the problem is solved.
I also changed shared parameters on the EasyDAClient class as you recommended before. I got an exception when applying them after the first instance of EasyDAClient class was created.
I have registered a separate topic
Change shared parameters causes exception
Regards
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The fix is is in the latest QuickOPC 2019.2, build 5.56.1055.1 or later.
Regards
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The item counts are quite high. In any case (independent of the fix), I recommend that you also do this:
EasyDAClient.ClientParameters.LinkCallbackQueueSize = 500000;
EasyDAClient.ClientParameters.RequestQueueSize = 500000;
EasyDAClient.ClientParameters.ResponseQueueSize = 500000;
EasyDAClient.EngineParameters.TopicLruSize = 500000;
EasyDAClient.EngineParameters.DefaultEventQueueSize = 500000;
Best regards
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it is very hard to count the number of opc items my application has subscribed to. it is about 20K -30K items, maybe more.
You can provide opc library debug symbols file or patch file to understand/verify your idea. If opc library supports debug logging I can enable it also.
Unfortunately this problem happens on the customer site
Best regards
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I have analyzed the call stacks. I do not see a true deadlock (two locks taken on two threads in reverse order). But most of the threads seem to be waiting for a "disconnect to happen on a particular server, and I do not see the thread that should be "working" on the disconnect. So in that sense, it is understandable that things get blocked.
But the question is, where is the thread that should have been working on the disconnect? It looks like that it is gone before it had a chance to notify the other thread (that is waiting on it) that the disconnect has been finished. I do not know the reason for that. I can guess that it has abnormally terminated - and that would be the true issue that we need to hunt. I am thinking that, just as a precaution, maybe I can add some code that would assure that the waiting thread is always notified. Need to think this through.
A question: How many items are you dealing with, roughly?
Regards
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