How to kill a negative SPID (like SPID -2) in SQL Server?

What to do next when you find SPID -2 in SQL Server

 Error: Process ID -2 is not a valid process ID
This article applies to:
 SQL Server 2000
 SQL Server 2005
 SQL Server 2008

You’ve been performing an investigation in SQL Server into a performance issue. Maybe some database blocking issue and you’ve done the usual things and you’ve just run an sp_who or sp_who2. Or perhaps you’ve been browsing the error log for potential problems and spotted an odd error message. But fundamentally, what you see is a SPID with a negative number. Specifically, SPID=-2. And it’s at the top of a blocking chain with a dozen other transactions behind it trying to acquire resource. Until it’s killed, nothing will happen.

Using KILL -2 Should Do It

So you do what you always do in these situations. Wait for it to complete, or more usually, because there’s an issue, you make a call on it and kill the SPID:
KILL -2

 And what comes back is:

Msg 6101, Level 16, State 1, Line 1
Process ID -2 is not a valid process ID. Choose a number between 1 and 2048

I’ll give you the fix first, you’re probably desperate for it (and it doesn’t involve restarting SQL Server). Then I’ll explain why:

Run the following (you’ll need to have a SQL Server login with sysadmin or processadmin privileges to do this):

select req_transactionUOW
 from master..syslockinfo
 where req_spid = -2

This will return a 32 digit UOW number which looks like a GUID. Something like ‘DEF12078-0199-1212-B810-CD46A73F2498’

Copy this into your query window and run:
KILL ‘DEF12078-0199-1212-B810-CD46A73F2498’

Run sp_who/sp_who2 again and you will probably see that the offending SPID has disappeared. If it hasn’t, it’s probably still in rollback and you’ll have to wait, but by nature this kind of SPID is usually pretty quick to roll back and terminate.