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Tuesday, November 1, 2011

Configuring a server side trace

When I’m after SQL Server performance  problems, SQL Server Profiler is still my number one tool. Allthough I know that extended events provide a mor lightweight solution, those are still a bit cumbersome to use (but I’ve seen that we can expect some improvements with SQL Server 2012).

When I’m using profiler to isolate performance issues, I try to configure server side traces, whenever possible. Fortunately, SQL Server Profiler will help you creating a script for a server side trace (File/Export/Script Trace Definition), so you don’t have to figure out all the event- and column-codes. Very good!

As I was doing the same configuration again and again, I decided to separate the TSQL code for the configuration inside a stored procedure.

And here comes dbo.configureServerSideTrace:

if object_id('dbo.configureServerSideTrace', 'P') is not null
  drop procedure dbo.configureServerSideTrace
go

-- Example for:
-- Start Trace
--   declare @traceID int
--   exec dbo.configureServerSideTrace @traceStatus = 1
--                                    ,@traceID = @traceID output
--                                    ,@maxFileSize = 10000
--                                    ,@traceFileName = N'e:\VMITrace\Undo'
--                                    ,@spId = @@spid
--
-- End Trace
--   exec dbo.configureServerSideTrace @traceStatus = 0, @traceID = @traceID



create procedure dbo.configureServerSideTrace
                                 (@traceStatus   bit                 
-- 1 => Start Trace
                                                                     
-- 0 => Stop Trace
                                 ,@traceID       int output          
-- If the Trace is started, this param will return the TraceID
                                                                     
-- For stopping the trace, the param has to be provided
                                 ,@spId          int           = null
-- provide the @@spid, if you want to filter only events for this conection
                                                                     
-- Optional. If not provided => no filter. Not needed for stopping the trace
                                 ,@maxFileSize   bigint        = 5000
-- Maximum Trace File Size in Megabyte. Trace will be stopped, if the filesize is reached.
                                 ,@traceFileName nvarchar(200) = null
-- Name of the trace file (server side!)
                                                                     
-- Optional. Not neded for stoping the trace
                                                                     
-- Attention! If the file already exists, the SP will yield an error
                                                                     
-- and no trace is started.
                                 )
as
begin

if
(@traceStatus = 0
)
begin
   exec sp_trace_setstatus @TraceID,
0
  
exec sp_trace_setstatus @TraceID,
2
  
return
;
end

-- Create a Queue
declare @rc
int

exec
@rc = sp_trace_create @TraceID output, 0, @traceFileName, @maxfilesize, NULL
if (@rc != 0) goto error

-- Set the events
declare @on
bit
set
@on = 1
exec sp_trace_setevent @TraceID, 43, 15, @on
exec sp_trace_setevent @TraceID, 43, 48, @on
exec sp_trace_setevent @TraceID, 43, 1, @on
exec sp_trace_setevent @TraceID, 43, 34, @on
exec sp_trace_setevent @TraceID, 43, 35, @on
exec sp_trace_setevent @TraceID, 43, 51, @on
exec sp_trace_setevent @TraceID, 43, 4, @on
exec sp_trace_setevent @TraceID, 43, 12, @on
exec sp_trace_setevent @TraceID, 43, 13, @on
exec sp_trace_setevent @TraceID, 43, 14, @on
exec sp_trace_setevent @TraceID, 43, 22, @on
exec sp_trace_setevent @TraceID, 42, 1, @on
exec sp_trace_setevent @TraceID, 42, 14, @on
exec sp_trace_setevent @TraceID, 42, 22, @on
exec sp_trace_setevent @TraceID, 42, 34, @on
exec sp_trace_setevent @TraceID, 42, 35, @on
exec sp_trace_setevent @TraceID, 42, 51, @on
exec sp_trace_setevent @TraceID, 42, 4, @on
exec sp_trace_setevent @TraceID, 42, 12, @on
exec sp_trace_setevent @TraceID, 45, 16, @on
exec sp_trace_setevent @TraceID, 45, 48, @on
exec sp_trace_setevent @TraceID, 45, 1, @on
exec sp_trace_setevent @TraceID, 45, 17, @on
exec sp_trace_setevent @TraceID, 45, 18, @on
exec sp_trace_setevent @TraceID, 45, 34, @on
exec sp_trace_setevent @TraceID, 45, 35, @on
exec sp_trace_setevent @TraceID, 45, 51, @on
exec sp_trace_setevent @TraceID, 45, 4, @on
exec sp_trace_setevent @TraceID, 45, 12, @on
exec sp_trace_setevent @TraceID, 45, 13, @on
exec sp_trace_setevent @TraceID, 45, 14, @on
exec sp_trace_setevent @TraceID, 45, 22, @on
exec sp_trace_setevent @TraceID, 45, 15, @on
-- XML Statistics Profile
exec sp_trace_setevent @TraceID, 146, 1, @on
exec sp_trace_setevent @TraceID, 146, 51, @on
exec sp_trace_setevent @TraceID, 146, 4, @on
exec sp_trace_setevent @TraceID, 146, 12, @on

-- Filter: Log only events for the provided @@spid
if @spId is not
null
  exec sp_trace_setfilter @TraceID, 12, 0, 0, @spID

-- Set the trace status to start
exec sp_trace_setstatus @TraceID, 1

goto finish

error:
select ErrorCode=@rc

finish:
end

go

Some annotations:

  • For the parameters, see the comments.
  • Don’t specify a filename extension for the trace file. .TRC will be added automatically.
  • Ensure that the output file does not already exist. Otherwise you’ll get an error.
  • Very often I replace the code for starting and stopping the trace inside “interesting code” inside a stored procedure. That is, I’m wrapping some more or less awkward code by starting and stopping a trace like this:

declare @traceID int
exec
dbo.configureServerSideTrace @traceStatus =
1
                                
,@traceID = @traceID
output
                                 ,@maxFileSize =
10000
                                
,@traceFileName =
N'e:\MyTrace\Test'
                                 ,@spId =
@@spid

--
-- Code of interest
--


exec dbo.configureServerSideTrace @traceStatus = 0, @traceID = @traceID

Cheers.

2 comments:

  1. Thanks for sharing this guide. I will try to configure server side trace in my home too. Keep posting!




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