Has anyone seen this behaviour before?
Imagine a office with 10 client computers and 1 server (MS SQL Server 2008 Ent 64 bits SP2 + MS Server 2008 Std 64 bits SP2)
Imagine client 1 set it firewall like this:
netsh advfirewall firewall add rule name="NoSQL" protocol=TCP dir=in remoteport=1433 action=block
Later, client 1 tries to connect to MS SQL Server, let's say with Management Studio (it doesn't matter)
Client 1 should get a timeout as he won't be able to get the reply from server. The rule set above should prevent any reply to reach client 1. The timeout last 20 seconds, which is the tcp/ip initial handshake timeout.
Up to this point, this looks just like a joke to user 1 (client 1 user) who will call support because his application can't connect to the database.
Now, while client 1 is having its particular timeout all the other clients are unable to connect to the server while that connection waits timeout. Once the connection timeouts clients are able to resume their work normally but, as connection timeout for
a normal connections string is 15 seconds, most of the clients get a timeout while connecting. Depends on when it connection started. The thing is MS SQL Server doesn't process any new connection till the connection with client 1 timeouts.
This only seems to affect Windows Server
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