# 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).

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:

If you have the better answer, then send it to us. We will display your answer after the approval.
Rules to Post Answers in CoolInterview.com:-

There should not be any Spelling Mistakes.

There should not be any Gramatical Errors.

Answers must not contain any bad words.

Answers should not be the repeat of same answer, already approved.

Answer should be complete in itself.

Name :*
Email Id :*
Answer :*
Verification Code	Not readable? Load New Code
Enter the above shown code:*
	Inform me about updated answers to this question