Over the weekend I was running into a blocking issue with one of my clients. I was using SQL Server 2008 and I was used to using the current activity pane in 2005 etc. to find the lead blocker. This is now gone in 2008 with the new Activity Monitor. I started to use a lot of the old ways to diagnose using the profiler etc but this is a very tedious process. I found this issue I was working on lastnight and it is resolved now but I did some searching on the web today and I found a really great article by Cherié Warren . Cherie does a great job describing the ways to do it in SQL 2008 so I would advise you all to take a look when you get a chance. She includes two really great scripts and I have included them below.
To gather Lock stats run the following query:
SELECT er.wait_time AS WaitMSQty
, er.session_id AS CallingSpId
, LEFT(nt_user_name, 30) AS CallingUserName
, LEFT(ces.program_name, 40) AS CallingProgramName
, er.blocking_session_id AS BlockingSpId
, DB_NAME(er.database_id) AS DbName
, CAST(csql.text AS varchar(255)) AS CallingSQL
, clck.CallingResourceId
, clck.CallingResourceType
, clck.CallingRequestMode
, CAST(bsql.text AS varchar(255)) AS BlockingSQL
, blck.BlockingResourceType
, blck.BlockingRequestMode
FROM master.sys.dm_exec_requests er WITH (NOLOCK)
JOIN master.sys.dm_exec_sessions ces WITH (NOLOCK)
ON er.session_id = ces.session_id
CROSS APPLY fn_get_sql (er.sql_handle) csql
JOIN (
-- Retrieve lock information for calling process, return only one record to
-- report information at the session level
SELECT cl.request_session_id AS CallingSpId
, MIN(cl.resource_associated_entity_id) AS CallingResourceId
, MIN(LEFT(cl.resource_type, 30)) AS CallingResourceType
, MIN(LEFT(cl.request_mode, 30)) AS CallingRequestMode
-- (i.e. schema, update, etc.)
FROM master.sys.dm_tran_locks cl WITH (nolock)
WHERE cl.request_status = 'WAIT' -- Status of the lock request = waiting
GROUP BY cl.request_session_id
) AS clck
ON er.session_id = clck.CallingSpid
JOIN (
-- Retrieve lock information for blocking process
-- Only one record will be returned (one possibility, for instance,
-- is for multiple row locks to occur)
SELECT bl.request_session_id AS BlockingSpId
, bl.resource_associated_entity_id AS BlockingResourceId
, MIN(LEFT(bl.resource_type, 30)) AS BlockingResourceType
, MIN(LEFT(bl.request_mode, 30)) AS BlockingRequestMode
FROM master.sys.dm_tran_locks bl WITH (nolock)
GROUP BY bl.request_session_id
, bl.resource_associated_entity_id
) AS blck
ON er.blocking_session_id = blck.BlockingSpId
AND clck.CallingResourceId = blck.BlockingResourceId
JOIN master.sys.dm_exec_connections ber WITH (NOLOCK)
ON er.blocking_session_id = ber.session_id
CROSS APPLY fn_get_sql (ber.most_recent_sql_handle) bsql
WHERE ces.is_user_process = 1
AND er.wait_time > 0
To review the objects run the following query:
DECLARE @SQL nvarchar(max)
, @CallingResourceType varchar(30)
, @Objectname sysname
, @DBName sysname
, @resource_associated_entity_id int
-- TODO: Set the variables for the object you wish to look up
SET @SQL = N'
USE ' + @DbName + N'
DECLARE @ObjectId int
SELECT @ObjectId = CASE
WHEN @CallingResourceType = ''OBJECT''
THEN @resource_associated_entity_id
WHEN @CallingResourceType IN (''HOBT'', ''RID'', ''KEY'',''PAGE'')
THEN (SELECT object_id
FROM sys.partitions
WHERE hobt_id = @resource_associated_entity_id)
WHEN @CallingResourceType = ''ALLOCATION_UNIT''
THEN (SELECT CASE
WHEN type IN (1, 3)
THEN (SELECT object_id
FROM sys.partitions
WHERE hobt_id = allocation_unit_id)
WHEN type = 2
THEN (SELECT object_id
FROM sys.partitions
WHERE partition_id = allocation_unit_id)
ELSE NULL
END
FROM sys.allocation_units
WHERE allocation_unit_id = @resource_associated_entity_id)
ELSE NULL
END
SELECT @ObjectName = OBJECT_NAME(@ObjectId)'
EXEC dbo.sp_executeSQL
@SQL
, N'@CallingResourceType varchar(30)
, @resource_associated_entity_id int
, @ObjectName sysname OUTPUT'
, @resource_associated_entity_id = @resource_associated_entity_id
, @CallingResourceType = @CallingResourceType
, @ObjectName = @ObjectName OUTPUT
