Network Tuning (HP-UX) for Oracle DataGuard

[tvrdileep]

Hai.
We would like to do some Network Throughout and Database Throughput tests to findout which is a better option between, HP Continuous Acess or Oracle DataGuard technologies. We are a major bank and we have about 10g R2 RAC (10.2.0.3) Databases using CFS and running on HP-UX 11i V2 Itanium in our Primary Site and we will be having 10 RAC DataGuards for these Primary RAC Databases.

So, In our basic tests using LGWR SYNC/ASYNC and ARCH mode of LOG Transport methods, we found a major time difference in completeing a huge transaction. So, we would like to do some Network Tuning like increase TCP/IP Send Buffer Size etc. Please let me know if anyone did the similar exercises. Also, I want to know how to do that on HP-UX 11.23 Itanium.

regards,
Dileep Tallam.

[tamilselvan]

1. To monitor network statistcis and retransmitted data, 
   executet the following command:
   netstat -s -p tcp

   If the num of retransmitted data packets is high, 
   then your network is not having enough bandwidth.

2.  The next command show all the tcp related parameters in 11.23
     ndd -get /dev/tcp ?

3. The parameters important for peformance are:
    tcp_conn_req_max  
    tcp_xmit_hiwater_def  
    tcp_ip_abort_interval  
    tcp_rexmit_interval_initial  
    tcp_keepalive_interval

[tvrdileep]

Hai Selvan.
Thanks for your info. I know the commands to check the parameters for the network protocols using "ndd"

I was actually looking for the changes to the Send and Receive Buffer Sizes:
(Obtained using "ndd -h supported")

tcp_recv_hiwater_max - Upper bound on TCP receive buffer size
tcp_xmit_hiwater_max - Upper bound on TCP send buffer size


Are you sure that we have to modify:

tcp_xmit_hiwater_def

Also, what are the maximum supported values and what are the other things they affect?

regards,
Dileep Tallam.

[tamilselvan]

Both parameters can be set to minimum of 512KB (524288 bytes).
I do not remember the maximum values. Try with 1MB and do some benchmark with various values.

[tvrdileep]

Hai Selvan.
Thanks for your info. The following are the current values that I took from my system:

$ ndd -get /dev/tcp tcp_recv_hiwater_def
32768
$
$ ndd -get /dev/tcp tcp_recv_hiwater_max
1073725440
$
$ ndd -get /dev/tcp tcp_xmit_hiwater_max
2147483647
$
$ ndd -get /dev/tcp tcp_conn_request_max
4096
$
$ ndd -get /dev/tcp tcp_ip_abort_interval
600000
$
$ ndd -get /dev/tcp tcp_keepalive_interval
7200000
$

Any Comments? Also, I wanted to know just setting the Buffer Sizes will do? I mean are there any dependent parameters which need to be set to avoid congestion or buffer overflow kind of situations?

regards,
Dileep Tallam.