Re: Oracle WAN performance questions

Nick Palmer wrote:
> 1) Why is the Oracle/SQL*Net/Net8 hitting us with 100ms latency, when the
> actual WAN latency is only 50ms? Can this be improved?
>
> 2) Should TNSPING always take more than double the PING time? If so, why ?
> Nick.
>

Unfortunately, TNSPING is not a good measure of what your Net8 communication is like. All TNSPING does is look up your command-line arg (the net8 db alias) in your tnsnames.ora file and then establish a handshake with the listener at the port specified. Note: 'ping' doesn't even do that much work (so is usually faster than tnsping).

When your application contacts the listener, it goes thru the same thing as TNSPING, but then it does some additional steps (depending on how you've set up your Net8 architecture - eg, MTS, dedicated/shared dispatchers, etc): the listener spawns a dispatcher (if required) and the dispatcher then opens a network communication channel with the client (over a different port).

If you have a firewall, this "different" port (between client and dispatcher) has to be recognized. Most firewall manufacturers know about the Net8 "hand-off" to a dispatcher, and allow for it (I've never done a timing study to see if this adds additional overhead).

Do you use MTS? Dedicated or shared dispatchers? Have you tweaked any of the Net8 parameters (eg, buffers, etc)?

Roger Crowley Received on Thu Jul 25 2002 - 15:27:27 CDT