St02 - Swaps in Red( Common but complicated)

[Former Member]

Hello Friends,

I am using SAP Netweaver 2004s, SAP_BASIS - 700, OS - Windows NT 6.1, DB- MSSQL 8.00.194.

In Tcode- ST02 i found many red alers while swapping. however many entires have hit ratio of 99% hopefully this can be ignored. please correct me if i am wrong. but 2 entries have less hit ratio the details are given below

Initial records 62.77 12,625 10,894 90.78 5,000 1,076 21.52 3,506 7,430

Initial record buffer IRBD

rsdb/ntab/irbdsize 12000 kB Size of initial record buffer

rsdb/ntab/entrycount 20000 Max. number / 2 of initial records buffered

Single record 73.95 20,000 4,494 22.63 500 375 75.00 1,033 , 824,053

Single record table buffer TABLP

rtbb/buffer_length 20000 kB Size of single record table buffer

rtbb/max_tables 500 Max. number of buffered tables

My Question is on what basis i can change this parameters? should i increase or decrease the parameter? how to find out exact digit of the profile parameters?

Thanks,

Shwetha

[rakesh_ranjan · Accepted solution]

Hi Shwetha,

If swap for program buffer is more than 10,000 per day. Its problem and you need to increase program buffer. Please note the value in St02 you see is cummulative value of swap, so if today its 15000 and tomorrow it becomes 40000 that means in a day it swapped by 25000. So if you see this daily increase by 10000 then its problem.

for other buffers also you need to check if they are swaping by 1000 on daily basis, probably indicates a problem and you need to increase those buffers.

regards,

rakesh

[Former Member]

Hi ShwethaKiran1,

I suggest, consult sap once.Request them, that you need their recommendations to fine tune the memory parameters.

I had requested SAP for the same, and they recommend few parameters to be change and zero administration.

Finally the result was wonder-full.. ...... I got superb performance.

Thanks & Regards,

Nagendra.

[Former Member]

Hi Shwetha,

The number of swaps you get per day is more relevant than the total number in ST02,

which is the swaps since the last system start.

Double click each line and then click the history button to see how many you get per day

The swap values you have don't seem that large if the machine has been up a few days.

You could try adding more to the single record buffer - perhaps double it.

We have always had a low hit rate in all our systems for the initial record buffer.

I have given up worrying about it.

Tony

Edited by: Tony Morrissey on Jul 8, 2010 1:58 PM