RPC performance

[Matthias Oswald]

Hi,

we are facing an RPC performance problem from our G-iMAN application.

The 32 KB TCP window size is not used completely, only 8 KB are used by the application. That is an application problem.

On the other hand our network aminsitrator notices also abnormal idle time inside a data block transfer (waiting for an ACK) before finishing the transfer. This is in contradiction with the TCP window size set to 32K. This can be a RPC issue on HP systems or an application issue according to him.

Does soemone have detailed knowledge of the RPC configuration on HP-UX11
or can advice on this issue ?

Thanks.

[Stefan Farrelly]

I remember this is configurable and once we couldnt get an application to change its size so we used ndd to modify the TCP window size down from 32k to suit the application.

You can see the configurable TCP settings with;
ndd -h supported

and grep for window. The one I think you need to change is tcp_recv_hiwater_def (although you may need tcp_recv_hiwater_lfp or nfp)
If you can set this to 8k on both ends of your RPC connection you can then see if it improves performance.

[Stefan Farrelly]

you may have to use ndd to change;
tcp_xmit_hiwater_def
also.