ST02 buffer tuning
Hi all,
In ST02 for Screen buffer and export/import Free directory entries and % are showing '0' , what does it mean ... Hit ratio for all buffers is 99.96 nearly for export/import it's showing 85% and swaps also rising .
Please suggest...
Thanks,
Subhash.G
Tune Buffers monitor shows the percentage usage of buffers and memory.
The Setups / Tune Buffers monitor displays data on:
- Buffer sizes
- Buffer qualities (hit ratios)
Bottlenecks may be indicated if buffer swaps occur
Choose Detail analysis menu to display other data, such as :
- Memory usage
- Semaphores usage
- Table calls
Max. use (in KB) should be less than In memory (in KB).
- The lower part of the Setups / Tune Buffers monitor displays data on:
- Extended memory size and usage
- Usage and configuration of the roll mechanism
Bottlenecks may be indicated if:
- For extended memory: Max use. = In memory
- For roll area: Max use. > In memory
good luck
if it useful reward points are appreciated
Similar Messages
-
Hi Gurus!
We having performance problem on some tcode lately (we are using sap R/3 4.7 on Windows - 2003 Server & our database is Oracle - 9i )
Can anybody give me an advice or link to sap notes or the other article or guide how to perform sap buffer tuning, and optimizing instance parameter ?
Thank you in advance.
Regards,
ShishirTask 1 :
Check for tables which are not buffered, but should be.
For example, check the customers:
Customising tables, (table names beginning with Y or Z)
Condition tables (for example, table A<nnn>, where nnn 500 to 999
Task 2 :
Check for tables which are buffered, but should not be.
For example, check large and frequently changed Customising
tables, such as:
Table TCURR (exchange rates)
Tables A005 (prices), A017 (customer/material), and A018 (vendor/material)
In the Online Service System (OSS), see also, for example, R/3 Notes 23877, 91335, and 34910 -
Dear All,
I want to clear ST02 buffer. But for that, I don't want to re-start SAP.
Is is possible to clear ST02 log without re-starting SAP.
Any T.code or report is available?
Regards,
NisitHi,
/$sync it will reset the buffer as well as number ranges too. so i recomend /$TAB instead of /$Sync.
/$TAB will just reset the buffer without restarting the system.
For more information click [Buffers|http://help.sap.com/erp2005_ehp_04/helpdata/EN/c4/3a6e98505211d189550000e829fbbd/frameset.htm]
With Regards,
Krishna. -
Buffer Tuning in ST02 Recommendations
I am looking for some advice as to how to change tune my buffers in our application servers. Their current settings are based off of SAPs, pre go-live checks. But to me they seem to need some adjusting.
Our server has 8GBs of RAM, so I feel like I definitely have some room to expand them.
What would you recommend I change the values to?
Here is a screenshot of the buffers - http://aycu07.webshots.com/image/20166/2003999813259508481_rs.jpg10k swaps per day is pretty high, especially for the PXA buffer. I'd definitely increase it if you have enough physical memory; the only impact is that it's going to allocated a larger chunk of shared memory, so if you don't have enough physical RAM to absorb the increase without swapping, you're not going to gain much. 500MB is pretty small for the program buffer these days, but that would depend on what modules you're running. I've hardly ever seen this below 1GB lately, and normally in the 1.5 - 2GB range for ERP systems with multiple modules implemented on a single app server.
The rule of thumb I've used is to try to keep at least 10% free (both space and # of entries). From your screen shot it looks like you need to increase the size of the field definition buffer, program buffer, CUA buffer, and export/import buffer.
Rich -
Hi
This is a new implementation with the configuration mentioned below.
Windows 2003 Server (SP1)
Oracle 9.2
8GB Ram
ECC 5.0
HP Proliant DL380G5 / Tape Device: HP DLT VS160
750GB Raid
I see a lot of Red Highlights under ST02
These are for
Swaps with value 1199334 for field description
Swaps with value 2030958 for Initial Records
Swaps with value 8715.952 for Program
Swaps with value 1080.867 for CUA
Swaps with value 173.431 for Screen
Swaps with value 2334 for Generic Key
Swaps with value 1087 for Single Record
Swaps with value 7689980 for Export / Import
As a result of the above and more, the production system seems very slow. The resopnse time for transactions (SAP Default) is on a average of 10 seconds, sometimes going up to one minute.There are no background jobs running during the day and no backups as well. The tablespace's and file system also have sufficient free space. There are sufficient work processes and we also check the size of archieve log on a regular basis (making sure Archieve not being a cause) I have a feeling that the errors could be because of incorrectly configured profile parameters, however identifying what is right and what isnt is becoming a difficult task.
You could see a snapshot of the ST02 screen here
http://img138.imageshack.us/my.php?image=st02outputxe7.png
Further here are the screenshots of CCMS buffer stats
http://img99.imageshack.us/my.php?image=ccmsbufferstatskq7.jpg
There are also a lot of table locks that i see
http://img263.imageshack.us/my.php?image=tablelock1rh3.jpg
http://img254.imageshack.us/my.php?image=tablelock2br9.jpg
http://img99.imageshack.us/my.php?image=tablelock3ta6.jpg
We will be going in for a Early watch support from SAP however till then we are stuck with these issues.
Could you share your ideas on how I can fix these ?
best regards
RaviHi Ravi,
You can use the following command to know what are all the parameters to be changed and what would be the prefferable values.
sappfpar check pf=
usr\sap\trans\tpparam
(or)
sappfpar check pf=
usr\sap\trans\tp_domain_<sid>
Regards,
N.Amarnath -
ST02(performance tuning)
Hi friends,
For the performance tuning I have put Tcode ST02 where in the below was shown in Red, Pls guide me how to proceed further
swaps
file description 7945(Red)
Initial records 11996(Red)
program 37372(Red)
CUA 17156(Red)
screen 2273(Red)
Generic Key 59(Red)
single record 19(Red)
export/import 26539(Red)
Pls clearly guide me how to proceed further....
Thanks in Advance
YedhiriDear Venu,
<removed_by_moderator>
Read the [Rules of Engagement|https://www.sdn.sap.com/irj/sdn/wiki?path=/display/home/rulesofEngagement]
Do not ask for points - This forum should be firstly about information exchange; points are an incentive and a way of saying thanks.
Asking for points is like asking someone to say "thank you": The only time we do this in real life is when teaching a child good manners. Saying it to an adult is insulting, so why do it in the forums? If someone keeps asking questions without awarding points, simply stop answering them or use the abuse button to report it.
Regards,
Ashutosh
Edited by: Juan Reyes on Jul 17, 2008 12:13 PM -
Memory buffer tuning - Why bother?
Hi
We are running ERP 6 on Win2003 64 bit, SQL2005 SP2 (2.6TB in size), 8 App servers with 16GB RAM (avg 60% used). As part of our housekeeping ,we are looking at addressing some of the swaps in ST02.
Currently we are experiencing swaps in the following buffers:
Nametab - Field definition: 150 000 swaps
Program: 300 000 swaps
Export/import: 500 000 swaps
Our current avg dialog response time is between 700-800ms per month (1400-1600 concurrent users).
Would increasing these buffers have any visable positive affect on the system or for the end-user? How important is it to address these buffer swaps? SAP does not report on it in the weekly/monthly EWA reports.
Regards,
CJHi,
You have quite a lot of swaps but you don't say if it is per day or since startup.
I just checked our own production ECC6 system and we have only about 600 to 1500 program buffer swaps on only 3 of the 6 app servers. zero swaps for other buffers.
But we get the same kind of monthly avg dialog response time (600 ms).
If you have time, you can tune your buffer sizes, it could only be better but you will not get a big improvement.
With a program buffer much too small, I 've already seen very bad performance but it is not your case.
Some times, I like to say : If it is not broken, don't fix it!
Regards,
Olivier -
Hello,
In Tcode ST02 --> Detailed Analysis, there is an option to check Table Call Statistics.
In that statistics page there is a column Buffer State
For table A807 the Buffer state is Error.
I tried searching but couldn't find anything on the Buffer State in Error.
COuld you help me with the reason and solution for this error?
Thanks.Analysis log
Date/time of analysis: 21.05.2010 11:34:42
Analyzed table: A807
Total number of rows: 4.234.059 rows
Requested bytes per row: 81 bytes per row
Requested bytes to be buffered 100%: 342.958.779 bytes
Current buffering mode: 100% buffering
Rows per Distinct 1 11 101 1.001 10.001 100.001 more than
neric key values - 10 - 100 - 1.000 - 10.000 - 100.000 -1.000.000 1.000.000
Key fields Number of areas that are specified by the generic key and contain the given number of rows
MANDT 1 0 0 0 0 0 0 1
KAPPL 1 0 0 0 0 0 0 1
KSCHL 6 0 0 2 0 1 2 1
PLTYP 41 7 8 4 1 12 9
MATNR 416.822 256.631 159.975 216
VARCOND 903.442 903.442
DATBI 4.234.059 4.234.059 -
Hello
I am trying to find out which table in SQL the buffer history (ST02) data is stored?
Please let me know.
Thank you
KenHi dude!
Clas Hortien's advise is simply great, as it will be useful not just to guess the tables you need right now but also in the future.
Just to help you in case you are not familiar with ST05: when you are reading the trace, you can summarize times in order to get it simpler and in a easier format to read (not just chronologic): go to the menu "Trace list" and select "Summarize Trace by SQL Statement (Shift+F8)". Under the column "Obj. name" there are the names of the tables read.
Cheers!!
--Jesú -
dear friends
in my devlopment server my buffer(st02) will not be refresh ? why ? and what i do for a refresh a buffer
this happend only in developmetn server
nainesh suthar
Edited by: ncsuthar on Mar 10, 2010 6:37 AMthank....u
pl visit above site
http://help.sap.com/saphelp_45b/helpdata/en/02/9625e3538111d1891b0000e8322f96/frameset.htm
it give more in detail
nainesh -
Hi Friends,
In our development system Swaps no is very high and it shows RED mark in st02
Table definition =25.213
Field definition = 357.579
Initial records = 62.209
program = 81.856
CUA = 12.158
Screen = 879
please check below attached screen shot for more details
Could you please any one help me how to resolve this issue..
Thanks in Advance
Regards,
VenkatHi Lisa,
SWAPs themselves are not an indicator of a performance issue.It's unlikely you can avoid them from happening in production systems. What matters is a quality of buffer tuning and a number of swaps hapenning every day. Let's say you are getting more then 10000 swaps each day for the program buffer. Then you'd need to pay attenation to this buffer and try to find out a way to reduce swaps.
Here is the link to SAP help:
http://help.sap.com/saphelp_erp2005vp/helpdata/en/c4/3a6ecc505211d189550000e829fbbd/content.htm
Regards,
Mike
Message was edited by: Mike Puzankov -
Hi Guys,
I would appreciate your assistance/recommendations with Buffer Tuning
Im experiencing high swapping on Several Buffer as shown Below
Which considerations would you take for adjusting these buffers to optimal Values?
Do you estimate the parameters values by incrementing by 10-20% ? Or is there a better way to determine the best values.
Thanks a lot for your help.
Nametab -->Table Definition
Efficiency HITRATIO % 97
HITS 119.405.209
REQUESTS 123.408.979
DB access quality % 97
DB access 4.006.836
DB access saved 119.399.849
Reorgs 0
Size Allocated KB 9.800
Available KB 8.219
Used KB 8.219
Free KB 0
Free KB 0
Directory entries Available 28.826
Used 28.826
Free 0
Swaps Objects swapped 1.032.168
Frames swapped 0
Resets Total 0
Table definition buffer TTAB
rsdb/ntab/entrycount 28826 Max. number of table definitions buffered
Nametab-->Field Definition
Efficiency HITRATIO % 100
HITS 80.761.920
REQUESTS 81.137.309
DB access quality % 100
DB access 363.063
DB access saved 80.761.378
Reorgs 0
Size Allocated KB 45.515
Available KB 43.263
Used KB 40.109
Free KB 3.154
Directory entries Available 28.826
Used 7.176
Free 21.650
Swaps Objects swapped 355.332
Frames swapped 0
Resets Total 0
rsdb/ntab/ftabsize 43263 kB Size of field description buffer
Program
Efficiency HITRATIO % 100
HITS 385.544.192
REQUESTS 385.922.653
DB access quality % 100
DB access 653.940
DB access saved 565.109.488
Reorgs 0
Size Allocated KB 400.000
Available KB 370.780
Used KB 369.428
Free KB 1.352
Gaps KB 1.303
Directory entries Available 100.000
Used 10.385
Free 89.615
Swaps Objects swapped 206.098
Frames swapped 0
Resets Total 0
Program buffer PXA
abap/buffersize 400000 kB Size of program buffer
abap/pxa shared Program buffer mode
Export/Import
Efficiency HITRATIO % 81
HITS 13.737.920
REQUESTS 16.906.841
DB access quality % 100
DB access 0
DB access saved 0
Reorgs 0
Size Allocated KB 4.096
Available KB 3.375
Used KB 2.757
Free KB 253
Directory entries Available 2.000
Used 1.031
Free 969
Swaps Objects swapped 32.476
Frames swapped 428.617*
Resets Total 0
Export/import buffer EIBUF
rsdb/obj/buffersize 4096 kB Size of export/import buffer
rsdb/obj/max_objects 2000 Max. number of objects in the buffer
rsdb/obj/large_object_size 8192 Bytes Estimation for the size of the largest object
rsdb/obj/mutex_n 0 Number of mutexes in Export/Import bufferHi Martin,
Since 20GB set to MSSQL DB, you can reserve 3GB for system application, process, backup, external process and etc.
Therefore, you can allocate 27GB to SAP system.
You can allocate 22GB to PHYS_MEMSIZE, abap/buffersize to 1000000 and 30% to SAP buffer in ST02 where you noticed alot of SWAP. Also, you can allocate additional space to rdisp/ROLL_SHM and rdisp/PG_SHM if the percentage of "In Memory used" is around or more than 80%.
You can check based on the history usage in ST02.
However, try not the exceed the shared memory of 27GB for total memory assigned for SAP system, you can check at ST02 -> detailed analysis -> storage.
Cheers,
Nicholas Chang -
DB_BLOCK_BUFFERS PARAMETER TUNING(ORACLE7)
제품 : ORACLE SERVER
작성날짜 : 2002-04-12
DB_BLOCK_BUFFERS PARAMETER TUNING(ORACLE7)
==========================================
Purpose
Oracle7 version의 database에서 db block buffer의 값이 적당한 지를
알아보고 Tuning 하는 방법을 알아보자.
Explanation
1. DB_BLOCK_BUFFERS parameter
(1) SGA 내 메모리에 캐쉬되는 데이타베이스 블럭의 수
(2) SGA 사이즈와 데이타베이스 성능을 결정하는 가장 중요한 요소이다.
(3) 높은 값을 갖게 되면 해당 블럭을 메모리에서 찾게 되는 빈도가 많아지기
때문에 디스크 입출력을 줄일 수 있지만, 보다 많은 메모리를 소모하게 된다.
2. 적정한 값 찾기
(1) 다음의 SQL문을 수행시켜 ratio 필드의 평균 값이 92% 이상이어야 한다.
- DBMS가 STARTUP 후부터 현재까지의 누적치를 보여준다.
- 현재의 HIT RATIO를 보려면 두 번 수행하여 차액을 갖고 계산한다.
rem
rem connect as system user id
rem
col logical_reads format 999,999,999,999
col physical_reads format 999,999,999,999
col physical_writes format 999,999,999,999
select a.value + b.value logical_reads,
c.value physical_reads,
round(100*(a.value+b.value-c.value)/(a.value+b.value),2) ratio,
d.value physical_writes
from sys.v_$sysstat a,
sys.v_$sysstat b,
sys.v_$sysstat c,
sys.v_$sysstat d
where a.statistic# = 37 -- db block gets
and b.statistic# = 38 -- consistent gets
and c.statistic# = 39 -- physical reads
and d.statistic# = 40 -- physical writes
(2) 적다고 생각될 때 initSID.ora 화일에서 다음을 고려한다.
DB_BLOCK_LRU_EXTENDED_STATISTICS = 1000
- 이 파라미터를 설정하고 다음의 SQL을 수행시킨다.
단, 값을 너무 크게 설정하면 심각한 퍼포먼스의 영향을 가져온다.
- 위의 1000 값의 의미는 현재보다 1000 까지 DB BLOCK을 더 늘렸을 때
cache hit가 증가하는 값을 알아보기 위함이다.
col Interval format a20
prompt Number of Additional Cache Hits (ACH)
select 200*trunc(indx/200)+1 || ' to ' ||
200*(trunc(indx/200)+1) "Interval",
sum(count) "Additional Buffer Cache Hits"
from sys.x$kcbrbh
group by trunc(indx/200)
Interval Additional Buffer Cache Hits
1 to 200 300
201 to 400 250
401 to 600 180
601 to 800 80
801 to 1000 50
(3) 많다고 생각될 때 init$ORACLE_SID.ora 화일에서 다음을 고려한다.
DB_BLOCK_LRU_STATISTICS=TRUE
- 이 파라미터를 설정하로 아래의 SQL을 실행하여 전체 버퍼에 대해 공헌하는
정도를 알아본다.
- 아래의 경우는 1 부터 600 까지의 버퍼만 사용되고 있음을 알 수 있다.
col Interval format a20
prompt Number of Losing Cache Hits (LCH)
select 200*trunc(indx/200)+1 || ' to ' ||
200*(trunc(indx/200)+1) "Interval",
sum(count) "Losing Buffer Cache Hits"
from sys.x$kcbcbh
group by trunc(indx/200)
Interval Losing Buffer Cache Hits
1 to 200 3915
201 to 400 434
401 to 600 199
601 to 800 0
9801 to 10000 0To MMM, the hit ratio is currently 100%. We want to lower that to about 95% and save some RAM at the expense of some slower queries.
To KM, no we are not using any stats_pack utilities.
Can anyone tell me the init.ora parameter to set in Oracle 8.1.7.4 to gets measures into the above table? -
Hi,
in st02 in table generic key velue (DB access) always high. will it affect the performce of the server.if yes how to solve the problem help me out. below shows the value of the generic key in st02
Buffer Swaps Database
accesses
Tables
Generic key 9 71,234
Thanx
KvlHello Kulandaivel,
at first you need to understand what the generic key buffer is .. please check the documentation here:
http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eaec446011d189700000e8322d00/content.htm
> will it affect the performce of the server
Yes it can, but don't have to. Check the buffered objects and the load on the database that is used for these tables.
> if yes how to solve the problem
There is no silver bullet.. every case is different.. check your tables .. maybe exclude them from the buffer if not needed... extend the buffer ... etc..
Regards
Stefan -
Regd: Screen Buffer size increase
Dear Sir/madam,
We check in ST02. the screen Buffer - SWAPS are More.
we want to increase the "SCREEN" Buffer size so the Screen Swaps comes down.
Screen buffer
zcsa/presentation_buffer_area 4400000 Byte Size of screen buffer
sap/bufdir_entries 2000 Max. number of buffered screens
Which parameter size i have to Increase here 2 Parameters are available. How much we can increase it.
here RAM size is 4GB. Any Formula is available to Increase the Buffer size of the Screen. or other like Program Buffer etc.
Regards
SNB.Thanks for your Reply.
Buffer Hitratio Allocated Free space Dir. size Free directory Swaps Database
[%] [kB] [kB] [%] Entries Entries [%] accesses
Screen 96.99 4,297 141 3.44 2,000 1,722 86.10 1,506 4,525
if we want to increase we have to increase for both the parameters.
zcsa/presentation_buffer_area 4400000 + 440000 = 4840000 (10%)
sap/bufdir_entries 2000 + 200 = 2200 (10%)
What is the difference between thest 2 parameters.
1) zcsa/presentation_buffer_area
2) sap/bufdir_entries
Do you have any Formula to Handle ST02 Buffer Size Parameter Maintanence.
Regards
SNB.
Maybe you are looking for
-
tried to reinstall OSX Mountain Lion 10.8.4 and every time i start with the installation i get a requested time out message, had to shut down my MacBook Pro retina. Now when i start up it automatically start internet recovery for two ouers. After the
-
Messages are not moving to Error Queue in OSB if Error is Raised
Hi All, My OSB process is as below. Queue1-->OSB-->Queue2. OSB Proxy is listening to the Queue1.When messages comes to Queue1 Proxy will pick the message and after applying the business logic it will put the message to Queue2. If OSB is not able to d
-
Accented characters in email fields
I'm using this script to have email sent to me through a mail form: <?php // initialize variables for To and Subject fields $to = '[email protected]'; $subject = 'Een testmail'; $from = $_POST["from"]; $email = $_POST["email"]; $comments = $_POST["co
-
Webcenter Startup for first time throwing lot of exceptions
Hi , I have done a fresh Installation of a linux 64 bit machine with 12GB RAM. When I start the Webcenter using the *./startManagedWebLogic.sh WC_Spaces "http://localhost:7001"* I get the follwoing exceptions. When I try to access the webcenter URL,
-
I'm finally getting the hang of this, but since updating to the current Paypal button extension in DW I'm getting strange code inseted on my pages.... <input type="hidden" name="mrb" value="R-3WH47588B4505740X"> <input type="hidden" name="pal" value=