In mirroring whta is role of failover partner? Where it is exactly placed? is it placed between Users and Primary/mirror server? Is failover partner receives signal of failover from witness server and divert users according to witness server signal? or failover partner work independently and directly with primery/mirror server without any signal from witness server? rgds
I'd recommend reading up articles such as
http://msdn.microsoft.com/en-us/library/ms189852.aspx (and those mentioned in the Resources section at the bottom of the article) and then if you try implementing Mirroring on your test server(s) and hit a problem then feel free to come back with a specific question
The TL;DR answer is that a failover partner - the Mirror, is the server receiving the transactions from the Primary database. If both the Mirror and the Witness server lose contact with the Primary but still can communicate with each other (form a quorum) a failover will be initiated. If the Mirror cannot "*see*" the Witness and the Primary it will not failover as it can't be sure of the need to do so. Users are *not* auto-directed to the mirror unless a load balancing mechanism is in place or the connect strings in the applications have a failover setting. The mirroring technology in SQL Server itself does not participate in that.