Killing a SPID and Checking Rollback progress in SQL Server
From time to time, I encounter blocking situations where I end up issuing a KILL command against the blocking SPID. When I run sp_who2, I can see the killed SPID is in a ROLLBACK state. Is there any way I can get an idea of how long the rollback for the SPID will take?
There sure is! The KILL command offers the WITH STATUSONLY argument which displays
an estimation of completion for an in progress ROLLBACK. Using KILL with this argument
does not kill a connection; it simply produces a progress report.
Run the following script in a new query window. It captures the connected SPID for the query and displays the fact that the SPID has an open transaction when the script completes:
set nocount on go select 'SPID = ' + cast(@@spid as varchar) -- what connection is this? go create table test (col1 int identity) -- create a test table go begin tran tran1 -- start a transaction while (1 = 1) begin insert test default values if scope_identity() > 999999 -- break after inserting 1m rows break end go dbcc opentran(0) go
Now open a new connection and issue the following statements to kill the connection we just opened and to examine the connection's state:
kill 52 go exec sp_who2 go
Now that we've KILLed the SPID, we can monitor its rollback progress by issuing KILL using the WITH STATUSONLY argument.
kill 52 with statusonly
As you can see, you can get a good estimation from the server of rollback progress.
- Read about KILL UOW in the SQL Server Books Online
- Read about DBCC OPENTRAN in the SQL Server Books Online
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