Connection Errors || onConnectTimeout MP unable to connect to backend

[Roaa]

Hi all ,,, 

We have a service callout policy. It calls an authorized and whitelisted source, most of the time it calls the source successfully but sometimes not ! it gives timeout error.

I tested the host and IP by using telnet it gives me connected so it not port issue

Error from MP logs:

2022-01-23 10:37:18,194 org:xxx env:staging api:xxxxxxx rev:76 messageid:apg-cv-s-nd03-16252-5752377-8  NIOThread@1 ERROR HTTP.CLIENT - HTTPClient$Context.onTimeout() :  ClientChannel[Connected:]@2066403 useCount=1 bytesRead=0 bytesWritten=0 age=3003ms  lastIO=3003ms  isOpen=true.onConnectTimeout host=accounts.accesscontrol.windows.net resolvedAddress=accounts.accesscontrol.windows.net/xx.xxx.xxx.xxx

What I see is: The MP is trying to connect to the source but it failed. Connection timeout period (Default: 3 seconds).

I am wondering why sometime it's failed to connect the source ! 

Any help and support ? 

Thanks