Modified the following parameter values

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EasyUAClient.AdaptableParameters.SessionParameters.ServerShutdownRetrialDelay = 5minutes

EasyUAClient.AdaptableParameters.SessionParameters.EndpointSelectionTimeout
EasyUAClient.AdaptableParameters.SessionParameters.SessionConnectTimeout
EasyUAClient.AdaptableParameters.SessionParameters.OperationTimeout
EasyUAClient.AdaptableParameters.SessionParameters.CloseTimeout

Close the final reply to the current article

1) After 2-3 months of actual operation observation, the problem has been basically solved at present
2) The reason is basically determined to be caused by the default connection parameter of QuickOpc's driver (EasyUaClient)
3) Scenario: The client connects to more than 10 machines normally, completes subscribing to multiple locations, and then the ServerConditionChange shows as disconnected. When EasyUaClient is reconnected, the organic rate thread count slowly increases. When multiple machines and locations are disconnected at the same time, after about 2-4 hours, the thread count reaches the 2000 limit
4) Solution: Modified the reconnection interval control
5) At present, such anomalies have not occurred again
6) Regarding this issue, it first appeared after December 27, 2023, when another problem was modified (the issue of delayed issuance from other machines caused by disconnection and reconnection)
www.opclabs.com/forum/ua-connections/3667-quickopc-reconnect-problem#12495
7) So far, QuickOpc has basically solved several major problems in my project practice.

Thanks
2024.8.6 17:17

xpycy001 wrote:

Hi ,support:

Review current issues
1） During the operation of the client, when the machine is disconnected, there is a connection exception that causes the thread to become larger, ultimately reaching the maximum thread pool limit ( ThreadPool Max Count: 2000)
2） has manually set the time interval for retry connections. For example, I set the interval to 5 minutes, but in reality, the connection is reconnected after 20 seconds. Please refer to the attached screenshot
3） I now want OpcUAclient to try reconnecting every five minutes for disconnected machines. How do I configure the parameters ？

current setting:
"RetryConnectDelay": 300,
"EndpointSelectionTimeout": 15000,
"SessionConnectTimeout": 60000,
"OperationTimeout": 120000,
"CloseTimeout": 5000,

easyUAClient.IsolatedParameters.SessionParameters.RetrialDelay = 300 * 1000;
EasyUAClient.AdaptableParameters.SessionParameters.RetrialDelay = 300 * 1000;

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Simon
2024.7.5 16:03

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Hi ,support:

Review current issues
1） During the operation of the client, when the machine is disconnected, there is a connection exception that causes the thread to become larger, ultimately reaching the maximum thread pool limit ( ThreadPool Max Count: 2000)
2） has manually set the time interval for retry connections. For example, I set the interval to 5 minutes, but in reality, the connection is reconnected after 20 seconds. Please refer to the attached screenshot
3） I now want OpcUAclient to try reconnecting every five minutes for disconnected machines. How do I configure the parameters ？

current setting:
"RetryConnectDelay": 300,
"EndpointSelectionTimeout": 15000,
"SessionConnectTimeout": 60000,
"OperationTimeout": 120000,
"CloseTimeout": 5000,

easyUAClient.IsolatedParameters.SessionParameters.RetrialDelay = 300 * 1000;
EasyUAClient.AdaptableParameters.SessionParameters.RetrialDelay = 300 * 1000;

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Simon
2024.7.5 16:03

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After a long period of observation, it has been preliminarily determined that this reconnection is caused by network anomalies. The only misunderstanding is that individual machines or points should be arranged in order, rather than reconnecting multiple tasks in parallel at the same point. The above is just personal speculation, so in order to solve the problem, the timeout parameter has been modified. If an exception occurs and the thread exceeds its maximum value and the time period becomes larger, it indicates that modifying the timeout parameter can help solve the problem

Hi , support:
The following information is recently collected

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Part A :
Regarding the issue of stopping production in this specific situation, a lot of tests have been conducted recently, and the environment is as follows:
1.1 We used 5 physical machines and simulated 12 VM virtual machines. Each virtual machine was templated with an opcServer (Kepserver) and imported 300 points,
1.2 There are a total of 12000 point configurations, of which 30 points are written back per second. Finally, a client. exe (EaseyUaClient) is used to connect simultaneously
1.3 Using unplugging the network cable, modifying the point path (simulating batch point not saving), and shutting down the virtual machine, after repeated attempts, the problem could not be reproduced, and finally abandoned this simulation.

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Part B:
1) Has been on the actual project site recently, with more than 30 clients in total, and a few of them have encountered anomalies again. I have conducted corresponding information collection
2) I have monitored the number of threads on each client. exe (EasyUAClient) end, and there is a slow growth of client threads, ranging from exceptions to reaching the upper limit, which takes about 1-4 hours before and after;
3) I extracted the dump document and opened and analyzed it using VS2022, with clear exception prompts
4) There are more than 1920 threads queuing, all waiting for another thread. I will delay taking a screenshot of the code location
5) The code for the most internal waiting;

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dump debugger:
[24256] NET ThreadPool Worker =>
UaSCUaBinaryClientChannel. cs=> line 265
1==>writeOperation End (int. MaxValue);==>// here....
Opc.Ua.Core.dll Opc.Ua.Bindings.ChannelAsyncOperation at line 185
2=>if (! M event. WaitOne (timeout)&&throwOnError) //here: WaitOne (timeout)

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at same time : 1,978 Threads blocked at same code line

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I Think , may be timeout too largue,retry interval too small

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I noticed the target m event Set() is related to timeout, I am trying to adjust the parameters
EndpointSelectionTimeout = 15* 1000
SessionConnectTimeout=15 * 1000
OperationTimeout=10 * 1000
CloseTimeout=5 * 1000
RetryConnectDelay=60*1000