You also can read the Chinese version: 秋天的林子---SQLSERVER的阻塞和死锁
Sys.SysProcesses: it's a important system view, it can locate and resolve block and deadlock.
Some fields(it from MSDN):
spid | smallint | SQL Server session ID. |
kpid | smallint | Windows thread ID. |
blocked | smallint | ID of the session that is blocking the request. If this column is NULL, the request is not blocked, or the session information of the blocking session is not available (or cannot be identified). -2 = The blocking resource is owned by an orphaned distributed transaction. -3 = The blocking resource is owned by a deferred recovery transaction. -4 = Session ID of the blocking latch owner could not be determined due to internal latch state transitions. |
waittype | binary(2) | Reserved. |
waittime | bigint | Current wait time in milliseconds. 0 = Process is not waiting. |
lastwaittype | nchar(32) | A string indicating the name of the last or current wait type. |
waitresource | nchar(256) | Textual representation of a lock resource. |
dbid | smallint | ID of the database currently being used by the process. |
uid | smallint | ID of the user that executed the command. Overflows or returns NULL if the number of users and roles exceeds 32,767. |
cpu | int | Cumulative CPU time for the process. The entry is updated for all processes, regardless of whether the SET STATISTICS TIME option is ON or OFF. |
physical_io | bigint | Cumulative disk reads and writes for the process. |
memusage | int | Number of pages in the procedure cache that are currently allocated to this process. A negative number indicates that the process is freeing memory allocated by another process. |
login_time | datetime | Time at which a client process logged into the server. |
last_batch | datetime | Last time a client process executed a remote stored procedure call or an EXECUTE statement. |
ecid | smallint | Execution context ID used to uniquely identify the subthreads operating on behalf of a single process. |
open_tran | smallint | Number of open transactions for the process. |
status | nchar(30) | Process ID status. The possible values are: dormant = SQL Server is resetting the session. running = The session is running one or more batches. When Multiple Active Result Sets (MARS) is enabled, a session can run multiple batches. For more information, see Using Multiple Active Result Sets (MARS). background = The session is running a background task, such as deadlock detection. rollback = The session has a transaction rollback in process. pending = The session is waiting for a worker thread to become available. runnable = The task in the session is in the runnable queue of a scheduler while waiting to get a time quantum. spinloop = The task in the session is waiting for a spinlock to become free. suspended = The session is waiting for an event, such as I/O, to complete. |
sid | binary(86) | Globally unique identifier (GUID) for the user. |
hostname | nchar(128) | Name of the workstation. |
program_name | nchar(128) | Name of the application program. |
hostprocess | nchar(10) | Workstation process ID number. |
cmd | nchar(16) | Command currently being executed. |
nt_domain | nchar(128) | Windows domain for the client, if using Windows Authentication, or a trusted connection. |
nt_username | nchar(128) | Windows user name for the process, if using Windows Authentication, or a trusted connection. |
net_address | nchar(12) | Assigned unique identifier for the network adapter on the workstation of each user. When a user logs in, this identifier is inserted in the net_address column. |
net_library | nchar(12) | Column in which the client's network library is stored. Every client process comes in on a network connection. Network connections have a network library associated with them that enables them to make the connection. |
loginame | nchar(128) | Login name. |
context_info | binary(128) | Data stored in a batch by using the SET CONTEXT_INFO statement. |
sql_handle | binary(20) | Represents the currently executing batch or object. Note This value is derived from the batch or memory address of the object. This value is not calculated by using the SQL Server hash-based algorithm. |
stmt_start | int | Starting offset of the current SQL statement for the specified sql_handle. |
stmt_end | int | Ending offset of the current SQL statement for the specified sql_handle. -1 = Current statement runs to the end of the results returned by the fn_get_sql function for the specified sql_handle. |
request_id | int | ID of request. Used to identify requests running in a specific session. |
page_resource | binary(8) | Applies to: SQL Server 2019 preview An 8-byte hexadecimal representation of the page resource if the waitresource column contains a page. |
example of application:
1. Check DB if have blocked
first to find which process's blocked filed is not 0. example: if rSPID53's blocked filed is not 0, it equal 52 and SPID's blockd is 0, you can get the conclusion now: blocked occurs, the process 53 is blocked by 52. in another situation, if you found that the blocked filed same as itself, it means the process is reading and writing disk.
2. Which DB is the process
only check dbid, using the following query
Select name,dbid from master.sys.sysdatabases
3. check the process corresponding SQL code
dbcc inputbuffer(spid);
4. KILL the process
kill spid
5. sql blocked and process query
select A.SPID as 'the process is blocked', a.CMD AS 'execute type',b.spid AS 'blocked process',b.cmd from master..sysprocesses a,master..sysprocesses b where a.blocked<>0 and a.blocked= b.spid DBCC INPUTBUFFER(59 ) exec sp_who 'active'--all of system process and the process is blocked if BLK field is not 0 exec sp_lock SPID --Returns a process lock on the resource situation SELECT object_name(1093578934)--Returns object ID corresponding object name DBCC INPUTBUFFER (63)--show the SPID's statement
6. SQL Server is running sql statements
SELECT spid, blocked, DB_NAME(sp.dbid) AS DBName, program_name, waitresource, lastwaittype, sp.loginame, sp.hostname, a.[Text] AS [TextData], SUBSTRING(A.text, sp.stmt_start / 2, (CASE WHEN sp.stmt_end = -1 THEN DATALENGTH(A.text) ELSE sp.stmt_end END - sp.stmt_start) / 2) AS [current_cmd] FROM sys.sysprocesses AS sp OUTER APPLY sys.dm_exec_sql_text (sp.sql_handle) AS A WHERE spid > 50 ORDER BY blocked DESC, DB_NAME(sp.dbid) ASC, a.[text];
SqlServer query deadlock process
select request_session_id spid, OBJECT_NAME(resource_associated_entity_id) tableName from sys.dm_tran_locks where resource_type='OBJECT'
as to sqlserver check deadlock kill lock
use master go create procedure sp_who_lock as begin declare @spid int,@bl int, @intTransactionCountOnEntry int, @intRowcount int, @intCountProperties int, @intCounter int create table #tmp_lock_who ( id int identity(1,1), spid smallint, bl smallint) IF @@ERROR<>0 RETURN @@ERROR insert into #tmp_lock_who(spid,bl) select 0 ,blocked from (select * from sysprocesses where blocked>0 ) a where not exists(select * from (select * from sysprocesses where blocked>0 ) b where a.blocked=spid) union select spid,blocked from sysprocesses where blocked>0 IF @@ERROR<>0 RETURN @@ERROR select @intCountProperties = Count(*),@intCounter = 1 from #tmp_lock_who IF @@ERROR<>0 RETURN @@ERROR if @intCountProperties=0 select 'no block and deadlock now' as message while @intCounter <= @intCountProperties begin select @spid = spid,@bl = bl from #tmp_lock_who where Id = @intCounter begin if @spid =0 select 'DB deadlock is caused by : '+ CAST(@bl AS VARCHAR(10)) + 'its statement is:' else select 'SPID:'+ CAST(@spid AS VARCHAR(10))+ ' is blocked by ' + 'SPID:'+ CAST(@bl AS VARCHAR(10)) +',its statement is:' DBCC INPUTBUFFER (@bl ) end set @intCounter = @intCounter + 1 end drop table #tmp_lock_who return 0 end
--kill lock and process
use master go if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[p_killspid]') and OBJECTPROPERTY(id, N'IsProcedure') = 1) drop procedure [dbo].[p_killspid] GO create proc p_killspid @dbname varchar(200) as declare @sql nvarchar(500) declare @spid nvarchar(20) declare #tb cursor for select spid=cast(spid as varchar(20)) from master..sysprocesses where dbid=db_id(@dbname) open #tb fetch next from #tb into @spid while @@fetch_status=0 begin exec('kill '+@spid) fetch next from #tb into @spid end close #tb deallocate #tb go --exec p_killspid 'newdbpy'
--view some lock information
create table #t(req_spid int,obj_name sysname) declare @s nvarchar(4000) ,@rid int,@dbname sysname,@id int,@objname sysname declare tb cursor for select distinct req_spid,dbname=db_name(rsc_dbid),rsc_objid from master..syslockinfo where rsc_type in(4,5) open tb fetch next from tb into @rid,@dbname,@id while @@fetch_status=0 begin set @s='select @objname=name from ['+@dbname+']..sysobjects where id=@id' exec sp_executesql @s,N'@objname sysname out,@id int',@objname out,@id insert into #t values(@rid,@objname) fetch next from tb into @rid,@dbname,@id end close tb deallocate tb select 'process id'=a.req_spid ,DB=db_name(rsc_dbid) ,'Type'=case rsc_type when 1 then 'NULL (no use)' when 2 then 'DB' when 3 then 'file' when 4 then 'Index' when 5 then 'table' when 6 then 'page' when 7 then 'key' when 8 then 'expand the disk' when 9 then 'RID(row ID)' when 10 then 'application' end ,rsc_objid ,b.obj_name ,rsc_indid from master..syslockinfo a left join #t b on a.req_spid=b.req_spid go drop table #t
--view no commit transaction
USE master GO SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED SELECT es.session_id, es.login_name, es.host_name, est.text , cn.last_read, cn.last_write, es.program_name FROM sys.dm_exec_sessions es INNER JOIN sys.dm_tran_session_transactions st ON es.session_id = st.session_id INNER JOIN sys.dm_exec_connections cn ON es.session_id = cn.session_id CROSS APPLY sys.dm_exec_sql_text(cn.most_recent_sql_handle) est LEFT OUTER JOIN sys.dm_exec_requests er ON st.session_id = er.session_id AND er.session_id IS NULL
view which tables is locked
select request_session_id spid,OBJECT_NAME(resource_associated_entity_id) tableName from sys.dm_tran_locks where resource_type='OBJECT'