There's probably nothing worse than not being able to start your SAP system … Especially the production system! Aside from the operating system and the database server you must pay close attention to certain places in SAP to find out what caused the problem and how to solve it. Here are the two places you will definitely need to check: EventViewer (Application and System logs) and the SAP Management Console (MMC).
EventViewer can provide useful information and it may help you pinpoint where the problem resides. The SAP MMC gives you the ability to visually see the system status (green, yellow or red lights), view the work processes status and view the developer traces, which are stored in the "work" directory. Example: /usr/sap/TST/DVEBMGS00/work.
For a central SAP instance to start successfully, both the message server and the dispatcher need to start. If one of them or both fail to start, users cannot log in to the system. The following scenarios will illustrate possible causes of why an SAP instance might not start and the reason of the message:
"*** DISPATCHER EMERGENCY SHUTDOWN ***".
Things you need to get familiar with:
- Developer Traces:
-- dev_disp Dispatcher developer trace
-- dev_ms Message Server developer trace
-- dev_wp0 Work process 0 developer trace
- The "services" file, which contains TCP and UDP services and their respective port numbers. This plain-text configuration file is located under %winnt%/system32/drivers/etc.
- Windows Task Manager (TASKMGR.exe).
- Dispatcher Monitor (DPMON.exe), which is located under /usr/sap/<SID>/sys/exe/run.
- Database logs.
- EventViewer (EVENTVWR.exe).
TROUBLESHOOTING SAP STARTUP PROBLEMS
Scenario 1: Dispatcher does not start due to a port conflict
Scenario 2: Dispatcher dies due to a database connection problem
Scenario 3: SAP does not start at all: no message server and no dispatcher
Scenario 4: Users get 'No logon possible' messages when they attempt to log in
Scenario 5: The message server starts but the dispatcher doesn't
Scenario 6: Work processes die soon after they start
Review:Conclusion and more resources
|ABOUT THE AUTHOR:|
| Giovanni Davila, technical author and SAP Basis expert
Giovanni Davila is an expert in SAP administration on the Windows platform. He has authored the critically-acclaimed books "SAP Basis Administration" and "SAP Basis Administration for Windows". He also wrote an article for the SAP Professional Journal titled "System Database Copies – Made Easy".
Copyright 2005 TechTarget