Question regarding Monitoring of system.

[Former Member]

hi all,

When you use transaction ST02, you get details about the buffers.

at the same time, you get the number of swaps occurred as well.

Can anyone tell me what these swaps actually mean.

Thankssssss

[former_member186775]

Hello Jack,

The red colored entries shows number of swaps since the last system

start for these we need to set parameters and which type of parameters to

change we can know in better way if you do it in the following way.

Double-click on your ST02 red swap one by one, this will bring you information on the swap your double-

clicked.

Now click on CURRENT PARAMETERS. This will tell you which parameters affect this swap.

you can then decide to increase these parameters.

Point to Note:

These values one can change only if he has pure knowledge of

wherein what effects if we give less or high value to those

parameters.Go through the materials online for complete

information.Changes made here without being sure might bring

serious changes.

regards,

Manjula.

[Former Member]

Hi Manjula,

Thankyou for your answer, however, my question is what do you mean by saying swaps are, I did what you suggested me to do, you are right, I am able to see all the parameters pertaining to their respective swap areas.

What I would like to know is, what are swaps, and how would I come to know that say in a productive system that uses say a 40 GB RAM, how much % should be allocated to the program buffer or to the CUA buffer. And yes would also like to know how does increase in the number of swaps affect the system performance, I tried finding information about the same, have inferred that it is something related to the context switching, not able to find more.

Anyways thanx for your help, hope you would respond incase if you know what the answers to my questions are, and by the way my actual name is Sreekul Nair....

thanks

Regards

Sreekul Nair....

[manu_susankar]

Hi Jack Dawson ,

Please check the belwo link, it will give you an idea what are buffers and swaps and how to tune them

http://help.sap.com/saphelp_erp2004/helpdata/EN/c4/3a6e98505211d189550000e829fbbd/frameset.htm

Regards,

S.Manu.

[Former Member]

If we talk about swaps in DB area then it means that the system could not read the data that was looking for in the SAP buffers and this is bad depending on why it happened, in an ideal SAP world (and from any point of view) it is more efficient to get info from RAM than from disk (it is faster of course). If Hit ratio is over 98% don´t worry much as ST02 is cumulative.