sap performance issue

[Former Member]

hi,

sometimes our sap system become very slow and after some it will ok it occurs several times in a week.can anyone tell me how to resolve actual problem. i tried all tcode like sm50,st02,st06... but i dont know how to reconize actual problem and where sap go slow.

[Former Member]

Hi Pawan,

In order to resolve the problem we need to understand what the problem is.Its a very generic statement that the system is slow.

You need to let us know as to which part of the system you seem to be having issues.

As suggested by others you need to fiirst segregate as to where the problem is os , db , sap.

If the issue reoccurs

OS : let us know how is the paging and memory and cpu in os07n

db : dbacockpit or st04old

then we can check for sap using stad as to where the issue might be or st03n

[Former Member]

Hi Pawan,

I assume that what you said it is a system level performance issue not an individual transaction/site issue. When the issue is happThere are many possible causes which can result in a system level performance issue. so what is starting point to track this down? I think the key is to understand where an affected transaction/program spends time. Whether it is spent in dispatcher queue waiting for available work processes, significant roll-in/rollout( memory issue), long process time but little cpu time( could be CPU contention), long database time( database issue) etc...

SAP transaction STAD can show where the time spend. You can compare the statistical records of a common transaction executed both when system is normal and when system is slow. This normally helps to identify next steps.

Also when system is slow, check system has enough "free" work process, enough CPU on database server( utilization < 80%), health of database lock status (DB01), health of application lock status, enough CPU on application server, enough memory(extended memory and heap memory utilization <80%).

Swap in non program areas should be avoided but some of swap in those area should not have significant impact. When you deal with ST02 setting, combination of buffer size and number of entry makes difference. Make sure both have free space.

Finally, you might watch the situation whether there is a pattern.. it is often found that one particular application which is a culprit - for example, system slow can be caused by shortage of work processes. Shortage of work process can happen if one application is launching many parallel processes and use up majority or all available work processes such as dialog etc...

Hope this help

[Former Member]

I would start with a simple top on the server, just to get an idea where i have to look further.

Cheers Michael

[Former Member]

i check these think.but i don't reconise wha value twill be right in these parameter. i always confused whenever this problem come and i cant do anything.

[former_member188883]

Hi Pawan,

Can you elaborate your analysis done. Like Whats the scenario for SAP buffer in ST02. Are there swaps happening ?

For top what is your observation.. how much is the RAM and CPU utilization.

Regards,

Deepak Kori

[Former Member]

hi deepak,

thanks for giving me reply. in st02 there is always swap space shown for e.g.

Buffer Swaps

Nametab (NTAB) 0

Table definition 0

Field definition 3,118

Short NTAB 0

Initial records 6,944

program 0

CUA 4,438

Screen 0

Calendar 0

OTR 0

Tables 0

Generic Key 6

Single record 0

Export/import 0

Exp./ Imp. SHM 0

And the cpu and RAM utilization is shown as below

CPU

Utilization user % 3

system % 1

idle % 72

io wait % 24

System calls/s 8979

Interrupts/s 1966

Memory

Physical mem avail Kb 16755292 Physical mem free Kb 495704

now tell me what i do at that time.

[former_member188883]

Hi Pawan,

As per the information shared by you, first step is to tune your buffer.

These are the buffers which swap.

Field definition 3,118

Initial records 6,944

CUA 4,438

What you need to do ?

1) Check which are the profile parameters related to above affected buffers. You can double click the buffer entries and then click on current objects to get a list of profile parameters related to that buffer.

2) Adjust the identified parameters by increasing the values

Later monitor the impact.

Second step:

=========

What is the database version you use ?

Check whether database parameters are tuned as per SAP recommended notes.

Regards,

Deepak Kori

[former_member524429]

Hi,

Since how many days you are facing Performance Issue in your SAP system ?

Any activities are done at SAP System (Application Server) level ? Database Level ? Os Level ?

Performance Analysis, Tuning & optimization is ONGOING Process.

As suggested by Venkatesh, you should first identify the problems weather it is at SAP System (Application Server) level, or at Database level or at Operating System level. Its Joint efforts of SAP/DB/OS team. After Identification of the possible causes, you should have to start your analysis at the affected Level. After guided analysis you can find the root cause of the Performance degradation.

You will need to go through the following REFERENCE SAP Notes to compare existing Parameter values set in your SAP Landscape.

Note 425207 - SAP memory management, current parameter ranges

Note 941735 - SAP memory management for 64-bit Linux systems

Note 146289 - Parameter Recommendations for 64-Bit SAP Kernel

Note 1171650 - Automated Oracle DB parameter check

Anyway, What its the value you see in ST04 for "Log.Reads/User Calls" under section Calls. If this ratio is greater than 30 than it is strongly indicating that your SAP system is running with Expensive SQL statements.

Linux Kernel release level ?

Once you provide the required details, one can guide you for the possible reason/solution.

Regards,

Bhavik G. Shroff

[former_member240656]

Hi Bhavik,

I'm attempting to troubleshoot performance issues on our SAP central instance, virtualized, production, ECC6/db2/Linux server.

I don't see the "Read/User Calls" ratio referred to. Am I in the correct screen; Transaction DB6PER > Calls tab?

Sorry for some reason I couldn't upload an image.

Calls

=======================================================================================================

Read                                    477,410,972,291          SELECT SQL                             1,333,698,405

Selected                               6,126,526,213              UPDATE/INSERT/DELETE      269,744,667

Deleted                                18,364,021                    DDL                                            2,124

Inserted                                32,385,658                   Elapsed Time (sec)                    2,375,017

Updated                               759,473,624                 Elapsed Time (microsec)           559,477

Rows Read / Rows Proc.   68.8

BP Gets / Rows Proc.        26.4

Total                                     2,590,740                     COMMITs                            192,432,754

Total Hash Loops               9,387                             Rollbacks                              351,351

Overflows                            7,764                             Dynamic SQL                       2,368,065,972

Small Overflows                  1,328                             Static SQL                           194,689,407

Post Threshold                         0                               Failed SQL                            6,929,697

This ratio would definitely provide me with some insight.

Regards,

Mike

[Former Member]

Hi Pawan,

Identify the bottlenecks in the system. Perf tuning is a vast area.

Start Analyzing from OS, DB and SAP.

Below are some basic aspects to look at.

OS

RAM utilization

CPU utilization

Swap utilization

DB

Instance parameters

Buffer Quality

Utilization of Buffer

SAP

ST03 Performance analysis

ST02 buffer utilization, Heap and extended memory areas

AL08 No. of users at different times

ST07

the list goes on, but the above should help you the initial analysis.

Br,

Venky