SAP system performance problems

[Former Member]

Hello,

I´m trying to understand something about how and what can be done to improve our SAP system performance.

First of all this is a SAP ERP system that is installed in a windows server 2003 on a MS SQL Server database (in a cluster - cluster administration). We noticed that the performance of this SAP system is not the better and some users told us that some actions during the transactions are slow. The two servers (two cluster nodes) have a lot of RAM memory and also page file so I believe this problems are not related with this particulary things.

Can you told/teach me how can I check and measure if the system are with some problems!? Which transactions I must check to make this analysis and how can I correct/improve this situation?

Can you tell me please some tips regarding this type of problems?

Thank you,

samid raif

[magexposito]

Hello SS,

A performance problem on the system can be caused for different reasons:

- Not enough resources during the process. For example, the extended memory of the system is exhausted an the process finish with an error. Or the CPU of the server is not enough and it will cause a bottleneck.

- Network problems or communication problems, between the different elements of the SAP systems or between users and system.

- Bad use of transaction by end users or user appreciation of the system performance.

- Etc.

I will check the following things to find where the performance issue is:

- Check the available resources of the system: Is there enough memory (roll, extended, heap) in the system (ST02)? Is the CPU at 100% or near 100% (ST06)? Is there enough physical memory all the time? What is the hit ratio % of each buffer on transaction ST02?

- Is there any dump on transaction ST22 that are related with insufficient memory on the system? Is there any message related with performance issues on transaction SM21, like for example connections timeout, message related with not enough resources, etc?

- Check the response times  for instance and logon groups on transaction SMLG. Which is the value?

- Check the hourly response times on transaction ST03. Compare them with previos values from other days, weeks or months, are they higher?

- Is the performance on the database good? Check transaction DB02. How is the CPU use on the database server?

- All the users complains about system performance or just some users? All the transactions or actions done in the system are affected by the performance problem or just some transactions?

Just to know, SAP doesn't make any real difference between Physical and SWAP memory. What I mean is that you define a pool of Virtual Memory between Physical and SWAP memory, then assign it to the SAP system with the system parameters and the SAP system uses that pool as it wants, so it is a normal situation if you find that SAP system is not using physical memory even if there is memory available. Of course there can be a problem related with wrong memory settings (for example, the amount of swap space you defined considering the physical memory of your server) but SAP systems doesn't always use physical memory.

Regards.

[Former Member]

Hello Miguel,

Thank you very much for the information detailed/explanation!

But can you check my previous message here, the values in ST02 transaction? Have you have an opinion or any tip about that values?!

Thank you,

samid raif

[magexposito]

Hello Samid,

The values showed on your screenshot are good:

- The Hit Ratio % of each buffer are between the recommended levels by SAP.

- There is no swaps on the buffers, just the Export/Import buffer has swaps and it is acceptable.

- There is enough roll, extended, paging and heap memory and it is not completed anytime.

Just one thing: You said on your last post that your SAP server has about 24GB RAM memory. Your extended memory is 13GB size and it should be higher because the virtual memory on your server should be 24GB RAM + Swap space defined (3xRAM Memory at least). Anyway, this is just a recommendation and it is not the performance issue.

Check the rest of topics I wrote on my answer. Also, how many work process has your server? Is there always dialog work process available all the time?

Best regards.