ST02 Swaps issue

[Former Member]

Hi Folks,

As per daily monotioring in ST02 i am getting swaps.Can any body advice me .Tunning the buffers is one solutiion i know this.but i am facing the problem daily .

My Environmet:

SAP--ECC6

DB-ORACLE-10.2.0.2.0

OS- AIX5.

[Former Member · Accepted solution]

Hi Vijay,

You may need to analyse the root cause of the swaps.... Couple of things you may check

1. Expensive SQL statements : Check if there are any SQL statements causing high load......If yes, then check with developers to optimize the same.

2. Reports running : Check if there are any reports which are causing the swaps.....The SQL statements might be from these reports....If yes, Then optimize the statements with the help of developers...

3. Check if the memory itself is low......If yes,Consider upgrading the same..

4. Have you taken restart of SAP instance and checked ?

Cheers...,

Raghu

[Former Member · Accepted solution]

Hi

You can Change Memory in RZ10-> instance Profile-> Basic Maintenance

[Former Member · Accepted solution]

Hi Raghu,

I restarted the instance but the issue remain same.One more thing we are not taking Offline back up due to bussines need system continiouis available.Please advice me.

Regards,

vizay.

[Former Member · Accepted solution]

Hi Srisap,

I know the configuration of parameters in RZ10.I think it's not at all possibile.Give me some other solution.

[former_member524429 · Accepted solution]

Hi,

When a buffer has not sufficient free-space or free directories, it has to swap objects out of the buffer in order to load a new object on request. The column Swap shows how many objects have been swapped out since system start-up.

Along with the useful suggestions provided by Raghu, I would do the following analysis to optimize the swaps by keeping in mind that "the performance optimization is an on going process".

1. Analyze the Hit Ratio and Swap Counts of each memory components in ST02. Prepare and Excel Sheet and note down the memory components which are required special attention for the performance of the system

e.g. If your PXA buffer is having more than 95% hit ration, but its showing more than 20000 swaps per day then you need to re-size it to reduce the swaps

2. Analyze the concurrent & active User Access to the SAP System and the workload.

3. Compare the existing Memory parameter and other dependent parameter settings (with respect to SAP system(s), Database and OS) with the recommendation suggested by SAP official Documents (Inst Guide, SAP Notes, etc..).

3. By keeping in mind the available RAM and SWAP Space, step-by-step, Increase the space value of affected Memory components by 10% to 20% of Existing settings.

4. If the System is configured with more work processes of same types and the all are not used at all even during peak workload (of month or of week or of year), then decrease the counts of work processes to reduce the memory usage so that we can optimize other required memory parameters with more space.

5. If the System is having not enough resources to provide better performance due to resource bottlenecks, then One will prefer:

- to upgrade the H/W on existing SAP System host

- to install additional Application Server(s) (on other system with highly equipped H/W resources), to take the advantage of Log-on Load Balancing.

Please refer these SAP Notes:

Note 750205 - High memory usage with AIX5.2/5.3 and Oracle9.2

Note 425207 - SAP memory management, current parameter ranges

Note 830576 - Parameter recommendations for Oracle 10g,

Note 146289 - Parameter Recommendations for 64-Bit SAP Kernel

One more thing we are not taking Offline back up due to business need system continuous available.Please advice me

Perform Consistent Online Backup (Online Backup + Redo Log Backup) and frequent Archive Log Backup.

Regards,

Bhavik G. Shroff

[nirmal_konchada · Accepted solution]

Hi,

Some swapping is fine but make sure your buffer hot ratio is above 95% , if its below 95% its a problem then.

Nirmal.