Showing results for 
Show  only  | Search instead for 
Did you mean: 

Server not responding in CAS


Hi All,

I have a file server got "Server not responding" errors quite often, the manual says due to server failed to respond. Meanwhile "connection refused","session termination" and "connection establishment" are zero, so it should not be resource issue. Is it an application level issue or network level issue? Anything else can investigate further?

Server not responding errors (id: ClntTmout)

The number of Server Not Responding errors. This category of errors applies when the client closes the TCP session with a RESET packet after the server has failed to respond for too long.




Dynatrace Pro
Dynatrace Pro

It could be an application issue. If there was an application thread that hung, server will not respond to client requests and AMD will detect that fact after client decided to quit.

But it is also likely that the app is built the way so this situation may be normal. When server has nothing more to send to the client, it just doesn't send anything despite client asking. Not the best seeding, but we have seen such things.

"Network" issue is also possible. Quoted because it's not really a network, but it might be some device in between, and it might be a legitimate behavior. If some proxy or firewall decided that this client's session should be immediately terminated, it may just not forward server packets to this client port anymore, without even sending any RST packet to notify client (sensible behavior from security standpoint).

Summarizing, if it is an issue that affects users and they complain - get a packet capture and investigate further.

Best regards

Thanks Kris. There are no firewall between VLAN segments, I guess it's likely application level issue. Since it is a file server which only provide network drive mapping to client workstations, SMB is the only traffic that we can see. It happen intermittently, just want to be prepared when user complain about performance. ^_^