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Starcounter is an in-memory database application engine.
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Network gateway not sending incoming UDP datagrams to app #438

Closed erikvk closed 6 years ago

erikvk commented 6 years ago

This issue is for reference – has already been discussed with @alemoi who is investigating

When having an Handle.Udp() in an app, listening for UDP datagrams in a production environment, we have noticed that the Starcounter network gateway can sometimes stop sending the incoming datagrams to the Starcounter app. When this happens, a network monitor tool like Wireshark or TCPView will still register the incoming datagrams, and even associate them with the scnetworkgateway process, but the UDP handle in the app code is not called.

Restarting the codehost (including restarting sccode) has no effect. Running staradmin kill all, and restarting the Starcounter service and application, however, fixes the issue.

Our conclusion is that the issue is located in the network gateway.

ghost commented 6 years ago

Just a status update: adding diagnostics and actively trying to figure out the problem.

dan31 commented 6 years ago

@erikvk @alemoi is it right you could not reproduce it anymore?

erikvk commented 6 years ago

@dan31 That's right. I am no longer able to reproduce the issue on our server. I have reached out to our customer, to see if they still have the issue.

My first guess is that this is somehow related to our code, in a way I'm unable to find, and that some update during the past weeks fixed it. Seems like a long shot, but still.

My second guess is that this is somehow time-related. We saw all hangs during the early hours of the day (2:00-6:00 AM), and we had the issue in august/early september, but not now. Also seems like a long shot.

I will let you know if this super elusive issue presents itself again.

Until then: ¯\_(ツ)_/¯

ghost commented 6 years ago

Let's have it closed for now. And when we experience any issues with UDP again - we will reopen it.