December 20, 2011 at 4:17 am
Hi All,
we are using SQL Server 2005 Working with Service broker technology along with replication.
we are getting timeout errors at application side, after my analysis i came to know that it is with blocking.
Here SPID 27 (system process :Task manager ) is blocking.
we are unable to find what is happening with this process (SPID :27).
we have used DBCC Inputbuffer and Opentran methods but we did nt get any information.
We have only one clue Opentran is showing :deleting from queue.
-- pls share if any one having information.
December 26, 2011 at 12:27 am
Try this
--########## Common Significant Wait types with BOL explanations ##################--------------
-- *** Network Related Waits ***
-- ASYNC_NETWORK_IO Occurs on network writes when the task is blocked behind the network
-- *** Locking Waits ***
-- LCK_M_IX Occurs when a task is waiting to acquire an Intent Exclusive (IX) lock
-- LCK_M_IU Occurs when a task is waiting to acquire an Intent Update (IU) lock
-- LCK_M_S Occurs when a task is waiting to acquire a Shared lock
-- *** I/O Related Waits ***
-- ASYNC_IO_COMPLETION Occurs when a task is waiting for I/Os to finish
-- IO_COMPLETION Occurs while waiting for I/O operations to complete.
-- This wait type generally represents non-data page I/Os. Data page I/O completion waits appear
-- as PAGEIOLATCH_* waits
-- PAGEIOLATCH_SH Occurs when a task is waiting on a latch for a buffer that is in an I/O request.
-- The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem.
-- PAGEIOLATCH_EX Occurs when a task is waiting on a latch for a buffer that is in an I/O request.
-- The latch request is in Exclusive mode. Long waits may indicate problems with the disk subsystem.
-- WRITELOG Occurs while waiting for a log flush to complete.
-- Common operations that cause log flushes are checkpoints and transaction commits.
-- PAGELATCH_EX Occurs when a task is waiting on a latch for a buffer that is not in an I/O request.
-- The latch request is in Exclusive mode.
-- BACKUPIO Occurs when a backup task is waiting for data, or is waiting for a buffer in which to store data
-- *** CPU Related Waits ***
-- SOS_SCHEDULER_YIELD Occurs when a task voluntarily yields the scheduler for other tasks to execute.
-- During this wait the task is waiting for its quantum to be renewed.
-- THREADPOOL Occurs when a task is waiting for a worker to run on.
-- This can indicate that the maximum worker setting is too low, or that batch executions are taking
-- unusually long, thus reducing the number of workers available to satisfy other batches.
-- CX_PACKET Occurs when trying to synchronize the query processor exchange iterator
-- You may consider lowering the degree of parallelism if contention on this wait type becomes a problem
WITH Waits AS
(
SELECT wait_type, wait_time_ms / 1000. AS wait_time_s,
100. * wait_time_ms / SUM(wait_time_ms) OVER() AS pct,
ROW_NUMBER() OVER(ORDER BY wait_time_ms DESC) AS rn
FROM sys.dm_os_wait_stats
WHERE wait_type NOT IN
(
'CLR_SEMAPHORE','LAZYWRITER_SLEEP','RESOURCE_QUEUE','SLEEP_TASK'
,'SLEEP_SYSTEMTASK','SQLTRACE_BUFFER_FLUSH','WAITFOR', 'LOGMGR_QUEUE','CHECKPOINT_QUEUE'
,'REQUEST_FOR_DEADLOCK_SEARCH','XE_TIMER_EVENT','BROKER_TO_FLUSH','BROKER_TASK_STOP','CLR_MANUAL_EVENT'
,'CLR_AUTO_EVENT','DISPATCHER_QUEUE_SEMAPHORE', 'FT_IFTS_SCHEDULER_IDLE_WAIT'
,'XE_DISPATCHER_WAIT', 'XE_DISPATCHER_JOIN'
)
)
SELECT
W1.wait_type,
CAST(W1.wait_time_s AS DECIMAL(12, 2)) AS wait_time_s,
CAST(W1.pct AS DECIMAL(12, 2)) AS pct,
CAST(SUM(W2.pct) AS DECIMAL(12, 2)) AS running_pct
FROM Waits AS W1
INNER JOIN Waits AS W2
ON W2.rn <= W1.rn
GROUP BY W1.rn, W1.wait_type, W1.wait_time_s, W1.pct
HAVING SUM(W2.pct) - W1.pct < 95; -- percentage threshold
--Check IO bottlenecks by PAGEIOLATCH_EX or PAGEIOLATCH_SH
select *
from sys.dm_os_wait_stats
where wait_type like 'PAGEIOLATCH%'
order by wait_type asc
select database_id,
file_id,
io_stall,
io_pending_ms_ticks,
scheduler_address
from sys.dm_io_virtual_file_stats(NULL, NULL) iovfs,
sys.dm_io_pending_io_requests as iopior
where iovfs.file_handle = iopior.io_handle
-------Bhuvnesh----------
I work only to learn Sql Server...though my company pays me for getting their stuff done;-)
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