My server becomes slow when more users login.
What could be the reason? Is it because of less hardware resource?
Server configuration is 104GB HDD, 2GB Ram.
OS:Win 2003 server.
Database:Oracle.
I manage SAP R/3 4.6C systems on Risc 6000 machines, under Oracle 9.2.
The overall performance problem for me is to know if SAP response time is acceptable ; if not, do this : – at AIX level : utilities are topas, to catch what’s wrong : Disk I/O ? CPU bottleneck ? Too much swap ? – at Oracle level : tkprof but don’t know much about this. – at SAP level : you can manage SAP memory, Oracle and OS too.
If SAP response time is acceptable, then try this :
Try to have a look at OS response time : ST06 : look at CPU, Memory, Swap, Disk and Lan response time.
Try to have a look at buffer quality : ST02, if many fields are red, investigate each fields dependant parameters.
Try to have a look at DB response time : ST04N, databuffer quality (SGA zone), how much physical reads / logical reads Ratio, wait times, number of user calls, Shared Pool cache hit ratio should be >96%, Sort usage, Redo logging.
I use this kind of procedure to manage my systems.
OR
It depends how much you allocated for SGA (database buffers, shared pool buffer, redo log buffers), how much you allocated for SAP buffers esp. Program buffers and whether the server have any other external processes/programs running.
How many Dialog Work Processes you allocated…I think your problem most likely is you don’t have enough of these Dialog processes. Also maybe users running inefficient reports/programs which are holding the Dialog processes, goto SM50 & check all DIA (Dialog) with status “waiting”…if ALL are “running” then you have wait time (problems !) for other users wanting to process transactions .
To troubleshoot performance, you need these tcode tools:-
ST04 – Database ß in here, check especially for Expensive SQLs (Detail Analysis à SQL Request)
ST02 – SAP buffers
ST06 – OS stats
ST05 – SQL trace
SE30 – Abap runtime analysis
OR
few step which you can exercise to sort/identify performance issues.
* ST03, ST02, ST04 are the tcode for workload, tuning and DB Performance Monitoring codes.
* ST06 FOR Operation System Monitoring.
** SM51 OR SM50 is process overview which tells you the workprocess sequence. ( Ideally 10-15 process with OLTP and batch process scheduled at peak and off peak times respectively) say 8-17 hrs and 17-8 hrs for Batch Process)
Operation Mode can be configured in RZ04 tcode.
** Check for top CPU in ST06 tcode. CPU should not exceed more than 60% for long time for any process.
** Based of No. of instances ( Application Servers ) should have adequately sized.
** Most resources intensive process have to be scheduled in Batch Process ( in Background in Non Peak Hours )
** Look for unnecessary Jobs Active During Prime Time
** Look for Parameters Set To Your Business Process.
( RZ10, RZ11 ) Check Snote:0124361
** Refer Early Watch Alert Periodically for Overall System Performance.. ( Tcode SDCC )
SAP System Performance Issues
SAP Workload Analysis
In order to perform analysis of a SAP software component the component should start without an error and there should be spare work processes available to run the analysis.
If there are no work processes available then use the program dpmon at the operating system level which will give the same output as the work process overview.
Workload Analysis (tcode ST03 or ST03N)
Menu Path
Tools=> Administration=> Monitor=> Performance=> Workload=> Analysis
Problem
Analysis
High database time i.e. more than 40% (database time = response time – wait time)
Check using tcode STAT / STAD if buffer reload then check ST10 for Table Access Statistics if OK, then use ST05 for SQL trace analysis.
Roll wait time more than 200 mseconds
Check using tcode ST05 for RFC trace
GUI time more than 200 mseconds
Check for networks bottlenecks
Load time more than 50 mseconds
Check the program buffer, maybe the program buffer too small
Roll out or roll in time more than 20 mseconds
Check SAP memory, problem cold be with SAP extended memory or SAP roll buffer
Programs with high CPU time i.e. >40%
Check ABAP program tcode SE30
Work Process Overview SM50 / SM66
Menu Path
Tools=> Administration=> Monitor=> Performance=> Exceptions / Users=> Active Users=> All processes
Work Processes with status running
Direct read, Sequential read, Insert, Update, Delete or Commit
Check databse locks tcode DB01, if exclusive lock wait, check process holding the lock.
Load Report or semaphore 1
SAP program buffer too small
Roll in, Roll out or semaphore 6
Check SAP memory problems due to extended memory or roll buffer
Work processes with status stopped
Reason PRIV
Check SAP memory problems due to extended memory or roll buffer
Reason CPIC
Test RFC destination using tcode SM59
Work process with status complete
Save the work process trace file and restart work process
Operating System Monitor ST06
High CPU load i.e. idle avarage <35%
SAP work process causing the high CPU load?
SM50 SM66 Check ABAP trace using tcode SE30
Database processes causing high CPU load?
ST04 Check expensive SQL statement
External processes causing high CPU load?
Postpone the process to off peak hours
File system cache >10% of RAM
Reduce file system cache
SAP Memory Configuration Monitor ST02
SAP extended memory >80%
Enlarge the SAP extended memory
Individual users consuming a lot of memory
Check user action
Many buffer swaps
Enlarge the related buffer
ztta/roll_first >1024
ztta/roll_first=1
Table Access Statistics ST10
Invalidations for buffered tables
If required deactivate buffering
Large buffer size for buffered tables
If required deactivate buffering
Many rows affected for buffered tables
If required deactivate buffering
Many total ABAP processor requests for non-buffered tables
If required activate buffering
