Buffer Parameter Increase???

[Former Member]

In one of the servers we are facing high number of swaps in the following buffers.

Program buffer (PXA)

CUA buffer (CUA)

Screen buffer (PRES)

Export/Import buffer (EIBUF)

To overcome this issue we have to increase the value in corresponding

Program buffer (PXA)

abap/buffersize

CUA buffer (CUA)

rsdb/cua/buffersize

Screen buffer (PRES)

zcsa/presentation_buffer_area

Export/Import buffer (EIBUF)

rsdb/obj/buffersize

My Question is how do I analyze how much Value should I increase for each of the Parameter.

Useful answers will be rewarded!

[Former Member · Accepted solution]

Hello,

In st02, double click on the parameter buffer that faces many swap, for exemple "Screen".

The following tab show you

Size Allocated KB

Available KB

Used KB

Free KB

Directory entries Available

Used

Free

This buffer is setup by 2 parameters (you can display them with 'current parameter button'):

zcsa/presentation_buffer_area

sap/bufdir_entries

One parameter is an amount of memory (in Bytes), the other represent a 'maximum number'.

To know if you need more memory place in the buffer or to increase the max number, you need to read the tab on the previous screen.

If the "Size" - "Free" is next to 0, you need to increase zcsa/presentation_buffer_area

If the "Directory entries"-"Free" is next to 0, you need to increase sap/bufdir_entries

There is no absolute rule to know in one row how much you need to increase every parameters for every buffer. It's more a question of 'fellings' and you often need to do many tests (change parameter, stopsap/startsap, re-change parameter, etc.).

For exemple

zcsa/presentation_buffer_area = 10000000

sap/bufdir_entries = 10000

If "Size"-"Free" is to 0 and "Directory entries"-"Free" is to 9000, this means you can have 9 times more directory entries but no more memory to hold them.

So, on this system 1000 buffer entries equals to 10Mb of memory.

So if "Objects swapped" is to 2000, just set zcsa/presentation_buffer_area = 10000000 +2*10000000

You don't have to modify sap/bufdir_entries because it can handle 9 more time entries.

If you want to handle in memory as much entries as the maximum directory entries, you could set zcsa/presentation_buffer_area = 10000000 + 9*10000000

Do the same way for every buffer with many swaps.

Hope this will help you.

Regards,

[Former Member]

Hello Praveen,

how do I analyze how much Value should I increase for each of the Parameter.

ans is check the memory measurement guide it solves all your issues.

also check the link

http://help.sap.com/saphelp_nw04/helpdata/en/02/962acd538111d1891b0000e8322f96/frameset.htm

Hope it helps

Regards,

Jafer