on 02-20-2014 10:55 AM
when i cheked in st02 swaps are showing red field description and intial records as below and we restarted sustem 10days back
Field definition 99,30 260.623 119.313 48,70 199.978 163.516 81,77 157.793 195.891
Initial records 32,39 13.249 1.442 20,60 49.994 30.125 60,26 70.118 89.991
which parameters i need to change? my platform is windows and oracle.and hit ratio is above 99.
Thanks in Advance.
Hi Arun,
The Hit ratio for Prorgam is 99% then it is well and fine. The swaps are more because of the memory pages are been swapped for some program that doesn`t use the frequently used data. Normally the memory size of each page is 8 KB ,so the swapping for the Program until 2000 is well and good.
Check for the program, batch job with the response time which consumes more time and swaps.
But for a single batch job or program if you start changing the parameter value, it would go beyond the limit. Also Check on program with variants having selection criteria with higher limits.
You can even evaluate with the EWA report.
Thanks & Regards,
Ahamed.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
To find out which parameters to change just dubbleclick on the parameter name in ST02.
E.g. Initial records and choose Curren parameters.
Read the notes before changing. Somethimes there are dependensies to other parameters.
Also check ipc/shm_psize* sizes with E.g. sappfpar before restarting the instance(s).
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
It would be easier if we could see the column headers to see if you've ran out of space or entries. A screen shot is often easier on the eye.
The parameters are:
Field description buffer FTAB
rsdb/ntab/ftabsize 300000 kB Size of field description buffer
rsdb/ntab/entrycount 200000 Max. number / 2 of table descriptions buffered
Initial record buffer IRBD
rsdb/ntab/irbdsize 19500 kB Size of initial record buffer
rsdb/ntab/entrycount 200000 Max. number / 2 of initial records buffered
There should be no swapping in these buffers at all (for optimal performance).
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
Hi Tony
present values of parameters
The parameters are:
Field description buffer FTAB
rsdb/ntab/ftabsize 245000 kB Size of field description buffer
rsdb/ntab/entrycount 199978 Max. number / 2 of table descriptions buffered
Initial record buffer IRBD
rsdb/ntab/irbdsize 7000 kB Size of initial record buffer
rsdb/ntab/entrycount 199978 Max. number / 2 of initial records buffered
Thanks
Can you paste in a screen shot of the ST02 values? If not, SAP normally recommend increasing the buffer sizes by 10% until swapping is eradicated. However, with these values, I'd double the size of rsdb/ntab/irbdsize and increase rsdb/ntab/ftabsize to 300000.
You also need to check if you have sufficient entries.
From the screen shot, we can observe:
NTAB Buffers
- Hit ratios above 99% should be fine.
- 'Field definition' is configured to max (300MB) in my system with no displacements. There's no harm doing the same in yours but the hit ratio is not too low (optimal is above 99.5% for all NTAB buffers).
- 'Initial records' is also configured to the max in my Windows system (60MB). I'd do the same in your system - it's only 60MB.
Program
- no issues with this buffer. Hit ratio is good (above 95%) and 10,000 per day is an acceptable number.
OTR
- Double it and increase the number of entries if they've been exausted. As the other poster stated. double click the buffer and then click on 'Current parameters', which gives you the relevant parameters.
Table Buffers
- These are also very performance relevant. High processing time for transaction steps can be an indicator for swapping causing problems. Use Table Call Statistics (transaction ST10) to check the maximum size calculated for the tables since startup. This can give you an idea of the buffer size but will grow as negative values are added.
Then as the other poster stated, execute sappfpar e.g. 'sappfpar pf=[DRIVE]:\usr\sap\<SID>\SYS\profile\[instance profile] check' and check for warnings/errors.
I recommend that you pick up a copy of SAP Performance Optimization Guide. It covers the buffers in detail and much much more.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.