Understanding the delay generated from SOAP client-server.

asked 2021-09-22 14:05:46 +0000


I have just upgraded my application from .NET framework to .NET core and one of our SOAP services is having random delays in its responses.

Next is added a snippet of the communication. Package nr 17060 - 17277 are regards a fast response from the server (less than 1s communication between server client.)

However I notice that randomly the server will answer with TCP retransmission as seen in the screenshot below. This exchange delays the entire process by about 20s until a new communication is retried at the package 21798.

image description

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Can you make a capture on the server to eliminate the network then begin to work up through the server logs?

Chuckc gravatar imageChuckc ( 2021-09-22 14:32:39 +0000 )edit

@Chuckc Sorry for the miss understanding, we are on control only over the client (were I took the logs). The server is an external services provided to us. Never had this issues beforehand, we have raised some issues with them but they still back up that the communication is good on their end.

patrickvibild gravatar imagepatrickvibild ( 2021-09-22 15:37:58 +0000 )edit

As always, please share a pcap file (not a screenshot) on a public file share site and post the link here. A screenshot is terrible to work with.

Jaap gravatar imageJaap ( 2021-09-22 16:16:51 +0000 )edit

"upgraded my application" - if nothing has changed on the server, how does the client app behave differently now after the upgrade? Is it making more requests to the server which might cause the server to run out of resources? Can you go back to the old application, make a baseline of network activity and compare that to new app?

Chuckc gravatar imageChuckc ( 2021-09-22 16:47:33 +0000 )edit

Are there many clients doing SOAP requests to the remote service? Which device is doing the NAT and are you able to make a capture on the public side of the NAT?

SYN-bit gravatar imageSYN-bit ( 2021-09-23 20:32:16 +0000 )edit