Hi,

I have an issue with a vWorkspace 7.5 environment. It's an environment with 2 Connection Brokers and several RD Session Hosts. All Windows Server 2008 R2.
When building up the user session, the RD Session Host servers are contacted to calculate the server with the least load.

Sometimes the Connection Broker log Shows:

1652 : 2160 - Username = ***\*******
1652 : 2160 - Client IP Address = ***.***.***.***
1652 : 2160 - Client IP Name = *********
1652 : 2160 - Trusted End Point IP Address = ***.***.***.***
1652 : 2160 - Two Factor Authenticate = 0
1652 : 2160 - OU List = OU=*****,DC=local
1652 : 2160 - Checking for disconnected session on server *********1...
1652 : 2160 - Checking for active session on server *********1...
1652 : 2160 - Server=*********1, Evaluator=Advanced RD Session Host, Score=787
1652 : 2160 - Checking for disconnected session on server *********2...
1652 : 2160 - Checking for active session on server *********2...
1652 : 2160 - Server=*********2, Evaluator=Advanced RD Session Host, Score=788
1652 : 2160 - Checking for disconnected session on server *********3...
1652 : 2160 - Checking for active session on server *********3...
1652 : 2160 - Server=*********3, Evaluator=Advanced RD Session Host, Score=803
1652 : 2160 - Checking for disconnected session on server *********4...
1652 : 2160 - Checking for active session on server *********4...
1652 : 2160 - Server=*********4, Evaluator=Advanced RD Session Host, Score=785
1652 : 2160 - Server lookup didn't find a server (servername=*********5)

This happens on both Connection Brokers servers and several different Session Host Servers, but not all the time and it's not consistently.
This could potentially cause a user to end up with multiple sessions if he has an active or disconnected session on the server that the Connection Broker marks as "does not find". We have experienced this on multiple occasions.

My question is what does the status "Server lookup didn't find a server" exactly mean? Did DNS lookup fail? Does it perform a ping? Does it check a certain port? Is the agent on the RD Session Host perhaps sometimes not responding?

What could cause this issue? Any suggestions on how to debug or fix this?