From: Ellen K. 

Note:  The names of the entities have been changed below.

I have a nightly maintenance job on one of my databases that has now failed
twice due to some kind of failure of the server to recognize the user.  The
job is a SQL Agent job with three steps:  some data maintenance, a data
integrity check, then a full backup to another machine on the network.

Last night it failed on the second step, a week ago it couldn't even start.

Here's what happened last night:

Step 1, which does some data maintenance on the database, succeeded with the message:
Executed as user: CORRECT_DOMAIN\correct_user. The step succeeded.

Step 2, which performs the database integrity check, failed with the message:
Unable to perform a SETUSER to the requested username
'CORRECT_DOMAIN\correct_user' because the username is invalid for
database 'Recordings'.  The step failed.

As noted, this is the second time I've had a problem with the user not
being recognized (see below for details of the first time) - and this
happened within one second.  (Step 1 usually has almost nothing to do and
it does it against an indexed column).

There is also the following warning in the application log of the box,
could this be related?
Event Type:     Warning
Event Source:   Perflib
Event Category: None
Event ID:       2003
Date:           7/28/2004
Time:           9:33:30 PM
User:           N/A
Computer:       CORRECT_SERVER
Description:
The configuration information of the performance library
"C:\WINNT\system32\w3ctrs.dll" for the  "W3SVC" service
does not match the trusted performance library information  stored in the
registry. The functions in this library will not be treated  as trusted.

Last week's failure was as follows:

The job failed.  Unable to determine if the owner (CORRECT_DOMAIN\ellen) of
job RecordingsNightlyMaintenance has server access (reason: Could not
obtain information about Windows NT group/user 'CORRECT_DOMAIN\ellen'.
[SQLSTATE 42000] (Error 8198)).

This happened at the moment of the attempt to start the process, i.e. NONE
of the steps were performed.

So something is going on with whatever enables the machine to know who
users are, but since I AM NOT AN {at}#$% ADMIN, that's as far as I can get.
:(

What do you guys think is going on and how does it get fixed?

Thanks in advance as always.   :)

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