how to know Who Is Blocking Your SQL Server?

Answer Posted / guest

If you have ever monitored any blocking problems in SQL
Server, you know that sp_who only shows you the spid (SQL
Server's internal Process ID) that is causing the blocking
for each spid that is blocked. Often a blocked spid is shown
as causing blocking for another spid. To see the spid (or
spids) that started the whole mess off, execute the
following SQL:

SELECT p.spid
,convert(char(12), d.name) db_name
, program_name
, convert(char(12), l.name) login_name
, convert(char(12), hostname) hostname
, cmd
, p.status
, p.blocked
, login_time
, last_batch
, p.spid
FROM master..sysprocesses p
JOIN master..sysdatabases d ON p.dbid = d.dbid
JOIN master..syslogins l ON p.suid = l.suid
WHERE p.blocked = 0
AND EXISTS ( SELECT 1
FROM master..sysprocesses p2
WHERE p2.blocked = p.spid )

We built this into our own version of sp_who, called
sp_hywho. See the listing below. Code for sp_hywho:

if exists (select * from sysobjects
where id = object_id('dbo.sp_hywho')
and sysstat & 0xf = 4)
drop procedure dbo.sp_hywho
GO

Create Procedure sp_hywho
( @vcDBName sysname = NULL )
AS

SET NOCOUNT ON

IF EXISTS ( SELECT 1
FROM master..sysprocesses p
WHERE p.blocked = 0
AND EXISTS ( SELECT 1
FROM master..sysprocesses p2
WHERE p2.blocked = p.spid ) )
BEGIN
PRINT "Blocking caused by:"
PRINT ""
SELECT p.spid
,convert(char(12), d.name) db_name
, program_name
, convert(char(12), l.name) login_name
, convert(char(12), hostname) hostname
, cmd
, p.status
, p.blocked
, login_time
, last_batch
, p.spid
FROM master..sysprocesses p
JOIN master..sysdatabases d ON p.dbid = d.dbid
JOIN master..syslogins l ON p.suid = l.suid
WHERE p.blocked = 0
AND EXISTS ( SELECT 1
FROM master..sysprocesses p2
WHERE p2.blocked = p.spid )
AND (p.dbid = DB_ID( @vcDBName ) OR @vcDBName IS NULL)
ORDER BY 2,IsNull(Ltrim(program_name),"ZZZZZZZZZ"),4,5
PRINT ""
END

SELECT p.spid
,convert(char(12), d.name) db_name
, program_name
, convert(char(12), l.name) login_name
, convert(char(12), hostname) hostname
, cmd
, p.status
, p.blocked
, login_time
, last_batch
, p.spid
FROM master..sysprocesses p
JOIN master..sysdatabases d ON p.dbid = d.dbid
JOIN master..syslogins l ON p.suid = l.suid
WHERE (p.dbid = DB_ID( @vcDBName ) OR @vcDBName IS NULL)
ORDER BY 2,IsNull(Ltrim(program_name),"ZZZZZZZZZ"),4,5


SET NOCOUNT OFF

GO

if exists (select * from sysobjects
where id = object_id('dbo.sp_hywho')
and sysstat & 0xf = 4)
GRANT EXEC ON dbo.sp_hywho TO PUBLIC
GO

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