Thursday, February 2, 2012

SAP Workload Analysis - Chapter 2 Performance Analysis Monitors


Chapter 2 – PERFORMANCE analysis MONITORS



Process overview – SM50

Type of work process
Name of the ABAP program running
Operating system PID number
Client being used
Name of the job executing
Current action
Number of detected errors in the work process
Table being utilized
Semaphore resource being used.
CPU accumulation
Time in process accumulation
User holding the resource

If all work processes are being blocked by long running transactions, the above information is also available at the OS level using the program dpmon.

In an R/3 system with more than one instance, you can access global work processes overview using SM66.

Work process overview using SM50 and SM66

Work process in status “running”?
Action : “Dir.Read”, “Seq.Read”, “Insert”, “Update”, “Delete”,
“Commit”.
Solution : Detailed analysis of the database.

Action: “Load Program?”
Solution: Detailed analysis of R/3 memory configuration (program buffer too small?)

Action: “Roll in/Roll out”?
Solution: Detailed analysis of R/3 Memory configuration (problems with extended memory or roll buffer)

Work process in status “stopped”?
Reason: “PRIV”?
Solution: Detailed analysis of R/3 memory configuration (problems with extended memory or roll buffer)
Reason: “CPIC”?
Solutions: Problems with CPIC connections such as “All work processes blocked in destination system?”



ST06 – Operating system monitor

Important statistics displayed in the os monitor include:

è  CPU load average and % CPU utilization.
è  Operating system swapping and % memory utilization.
è  % disk utilization.
è  Operating system configuration parameters.
CPU bottlenecks are indicated during several snapshots by:
* Idle CPU < 10%
* Load Average: N processes waiting in front of the CPU.
Memory bottlenecks are indicated during several snapshots by:
* An increase in page outs for UNIX or page ins for NT.
Go to -> Current data -> Snap shot -> Top CPU users
  • This lists the top processes utilizing the maximum CPU time
  • “ Disp + work” signifies an R/3 work process.
  • “ORACLE80” signifies a database process.
  • “DOC_SYNDER”/”DR.WATSON” ETC., is an external processes which does not belong to an R/3 instance or to the database. External processes may affect performance critically.





Setups / Tune buffers – ST02



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.


Maximum 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.
Performance chart to be maintained for reference
CPU load
Allocated memory       2,087,664 MB
Physical memory                    2 GB
Top 5 Transactions     Related R/3 Modules               Related Response times
1. Session manager      1.  BASIS                                              1. 12
2. Auto ABAP              2. ABAP                                               2. 9
3. SU01                        3. BASIS                                               3. 4
4. ST03N                      4. BASIS                                               4. 3
5. (B) Others                5. Others                                             5. 1
Buffer Swaps:
Buffer:             NTAB                                       Amount: 0
Buffer:             Program                                  Amount: 0
Buffer:             Tables                                      Amount: 8
Buffer:             Export/Import             Amount: 0
Buffer:             Export/Import SHM                Amount: 0
Operating system paging: Yes            Amount:          30 KB/S
Work process overview – SM50
ST03 – Work load monitor
ST02 – Setup/Tune up buffers
An example for poor configuration
The program buffer is set to 110 MB (SAP instance profile parameter Buffer size is set to 110,000) and simulation of 10 users for each of MM, SD and PP is started.
An example for optimal configuration
The program buffer is set to 400 MB (SAP instance profile parameter Buffer size is set to 400,000) and the simulation is started. The program buffer is now big enough to hold all necessary code.
ST03N – workload analysis
ST02 – Tune summary

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