(转)SQL Server 监控统计阻塞脚本信息

数据库产生阻塞(Blocking)的本质原因 :SQL语句连续持有锁的时间过长 ,数目过多, 粒度过大。阻塞是事务隔离带来的副作用,它是不可避免的,而且是一个数据库系统常见的现象。 但是阻塞的时间和出现频率要控制在一定的范围内,阻塞持续的时间过长或阻塞出现过多(过于频繁),就会对数据库性能产生严重的影响。

    很多时候,DBA需要知道数据库在出现性能问题时,有没有发生阻塞? 什么时候开始的?发生在那个数据库上? 阻塞发生在那些SQL语句之间? 阻塞的时间有多长? 阻塞发生的频率? 阻塞有关的连接是从那些客户端应用发送来的?.......

    如果我们能够知道这些具体信息,我们就能迅速定位问题,分析阻塞产生的原因,  从而找出出现性能问题的根本原因,并根据具体原因给出相应的解决方案(索引调整、优化SQL语句等)。

    查看阻塞的方法比较多, 我在这篇博客MS SQL 日常维护管理常用脚本(二)里面提到查看阻塞的一些方法:

方法1:查看那个引起阻塞,查看blk不为0的记录,如果存在阻塞进程,则是该阻塞进程的会话 ID。否则该列为零。

    EXEC sp_who active

方法2:查看那个引起阻塞,查看字段BlkBy,这个能够得到比sp_who更多的信息。

    EXEC sp_who2 active

方法3:sp_lock 系统存储过程,报告有关锁的信息,但是不方便定位问题

方法4:sp_who_lock存储过程

方法5:右键服务器-选择“活动和监视器”,查看进程选项。注意“任务状态”字段。

方法6:右键服务名称-选择报表-标准报表-活动-所有正在阻塞的事务。

但是上面方法,例如像sp_who、 sp_who2,sp_who_lock等,都有或多或少的缺点:例如不能查看阻塞和被阻塞的SQL语句。不能从查看一段时间内阻塞发生的情况等;没有显示阻塞的时间....... 我们要实现下面功能:

    1:  查看那个会话阻塞了那个会话

    2:阻塞会话和被阻塞会话正在执行的SQL语句

    3:被阻塞了多长时间

    4:像客户端IP、Proagram_Name之类信息

    5:阻塞发生的时间点

    6:阻塞发生的频率

    7:如果需要,应该通知相关开发人员,DBA不能啥事情都包揽是吧,那不还得累死,总得让开发人员员参与进来优化(有些问题就该他们解决),多了解一些系统运行的具体情况,有利于他们认识问题、解决问题。

    8:需要的时候开启这项功能,不需要关闭这项功能

于是为了满足上述功能,有了下面SQL 语句

SELECT wt.blocking_session_id                  AS BlockingSessesionId
      ,sp.program_name                         AS ProgramName
      ,COALESCE(sp.LOGINAME, sp.nt_username)   AS HostName    
      ,ec1.client_net_address                  AS ClientIpAddress
      ,db.name                                 AS DatabaseName        
      ,wt.wait_type                            AS WaitType                    
      ,ec1.connect_time                        AS BlockingStartTime
      ,wt.WAIT_DURATION_MS/1000                AS WaitDuration
      ,ec1.session_id                          AS BlockedSessionId
      ,h1.TEXT                                 AS BlockedSQLText
      ,h2.TEXT                                 AS BlockingSQLText
FROM sys.dm_tran_locks AS tl
INNER JOIN sys.databases db
  ON db.database_id = tl.resource_database_id
INNER JOIN sys.dm_os_waiting_tasks AS wt
  ON tl.lock_owner_address = wt.resource_address
INNER JOIN sys.dm_exec_connections ec1
  ON ec1.session_id = tl.request_session_id
INNER JOIN sys.dm_exec_connections ec2
  ON ec2.session_id = wt.blocking_session_id
LEFT OUTER JOIN master.dbo.sysprocesses sp
  ON SP.spid = wt.blocking_session_id
CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2

我们做一个测试例子来验证一下

 

1:打开第一会话窗口1,执行下面语句

USE DBMonitor;
 
GO
 
BEGIN TRANSACTION
 
SELECT * FROM dbo.TEST(TABLOCKX);
 
--COMMIT TRANSACTION;
 

2:打开第二个会话窗口2,执行下面语句

USE DBMonitor;
GO
SELECT * FROM dbo.TEST

3:打开第三个会话窗口3,执行下面语句

SELECT wt.blocking_session_id                  AS BlockingSessesionId
      ,sp.program_name                         AS ProgramName
      ,COALESCE(sp.LOGINAME, sp.nt_username)   AS HostName    
      ,ec1.client_net_address                  AS ClientIpAddress
      ,db.name                                 AS DatabaseName        
      ,wt.wait_type                            AS WaitType                    
      ,ec1.connect_time                        AS BlockingStartTime
      ,wt.WAIT_DURATION_MS/1000                AS WaitDuration
      ,ec1.session_id                          AS BlockedSessionId
      ,h1.TEXT                                 AS BlockedSQLText
      ,h2.TEXT                                 AS BlockingSQLText
FROM sys.dm_tran_locks AS tl
INNER JOIN sys.databases db
  ON db.database_id = tl.resource_database_id
INNER JOIN sys.dm_os_waiting_tasks AS wt
  ON tl.lock_owner_address = wt.resource_address
INNER JOIN sys.dm_exec_connections ec1
  ON ec1.session_id = tl.request_session_id
INNER JOIN sys.dm_exec_connections ec2
  ON ec2.session_id = wt.blocking_session_id
LEFT OUTER JOIN master.dbo.sysprocesses sp
  ON SP.spid = wt.blocking_session_id
CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2

如下图所,我们可以看到阻塞其它会话以及被阻塞会话的信息,如下所示

image

现在上面SQL已经基本实现了查看阻塞具体信息的功能,但是现在又有几个问题:

          1:上面SQL脚本只适合已经出现阻塞情况下查看阻塞信息,如果没有出现阻塞情况,我总不能傻傻的一直在哪里点击执行吧,因为阻塞这种情况有可能在那段时间都不会出现,只会在特定的时间段出现。

          2:我想了解一段时间内数据库出现的阻塞情况,那么需要将阻塞信息保留下来。

         3:有时候忙不过来,我想将这些具体阻塞信息发送给相关开发人员,让他们了解具体情况。

于是我想通过一个存储过程来实现这方面功能,通过设置参数@OutType,默认为输出阻塞会话信息,当参数为"Table" 时,将阻塞信息写入数据库表,如果参数为 "Email"表示将阻塞信息通过邮件发送开发人员。

正好这段时间,我在YourSQLDba上扩展一些功能,于是我将这个存储过程放置在YouSQLDba数据库中。

USE [YourSQLDba]
GO
 
IF NOT EXISTS(SELECT * FROM sys.objects WHERE object_id=OBJECT_ID(N'[Maint].[BlockingSQLHistory]') AND type='U')
BEGIN
CREATE TABLE Maint.BlockingSQLHistory
(               
                RecordTime                        DATETIME           ,
                DatabaseName                      SYSNAME            ,
                BlockingSessesionId               SMALLINT           ,
                ProgramName                       NCHAR(128)         ,
                UserName                          NCHAR(256)         ,
                ClientIpAddress                   VARCHAR(48)        ,
                WaitType                          NCHAR(60)          ,
                BlockingStartTime                 DATETIME           ,
                WaitDuration                      BIGINT             ,
                BlockedSessionId                  INT                ,        
                BlockedSQLText                    NVARCHAR(MAX)      ,
                BlockingSQLText                   NVARCHAR(MAX)      ,
                CONSTRAINT PK_BlockingSQLHistory  PRIMARY KEY(RecordTime)
)
 
END
GO

存储过程如下所示:

USE [YourSQLDba]
GO
 
IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[Maint].[sp_who_blocking]') AND type in (N'P', N'PC'))
DROP PROCEDURE [Maint].[sp_who_blocking]
GO
 
 
 
 
 
SET ANSI_NULLS ON
GO
 
SET QUOTED_IDENTIFIER ON
GO
 
 
 
--==================================================================================================================
--        ProcedureName         :            [Maint].[sp_who_blocking]
--        Author                :            Kerry    http://www.cnblogs.com/kerrycode/
--        CreateDate            :            2014-04-23
--        Description           :            监控数据库阻塞情况,显示阻塞会话信息或收集阻塞会话信息或发送告警邮件
/******************************************************************************************************************
        Parameters                   :                                    参数说明
********************************************************************************************************************
            @OutType         :            默认为输出阻塞会话信息,"Table", "Email"分别表示将阻塞信息写入表或邮件发送
            @EmailSubject    :            邮件主题.默认为Sql Blocking Alert,一般指定,例如“ServerName Sql Blocking Alert"
            @ProfileName     :            @profile_name 默认值为YourSQLDba_EmailProfile
            @RecipientsLst   :            收件人列表
********************************************************************************************************************
   Modified Date    Modified User     Version                 Modified Reason
********************************************************************************************************************
    2014-04-23             Kerry         V01.00.00         新建存储过程[Maint].[sp_who_blocking]

*******************************************************************************************************************/
--==================================================================================================================
CREATE PROCEDURE [Maint].[sp_who_blocking]
(
        @OutType    
            VARCHAR(8) ='Default'                  ,
        @EmailSubject         
            VARCHAR(120)='Sql Blocking Alert'      ,
        @ProfileName         
            sysname='YourSQLDba_EmailProfile'      ,
        @RecipientsLst 
             VARCHAR(MAX) = NULL
)
AS
BEGIN
 
SET NOCOUNT ON;
 
DECLARE @HtmlContent  NVARCHAR(MAX) ;
 
    IF @OutType NOT IN ('Default', 'Table','Email')
    BEGIN
        PRINT 'The parameter @OutType is not correct,please check it';
        
        return;
    END
 
    IF @OutType ='Default'
        BEGIN
        
              SELECT db.name                                 AS DatabaseName    
                    ,wt.blocking_session_id                  AS BlockingSessesionId
                    ,sp.program_name                         AS ProgramName
                    ,COALESCE(sp.LOGINAME, sp.nt_username)   AS UserName    
                    ,ec1.client_net_address                  AS ClientIpAddress    
                    ,wt.wait_type                            AS WaitType                    
                    ,ec1.connect_time                        AS BlockingStartTime
                    ,wt.WAIT_DURATION_MS/1000                AS WaitDuration
                    ,ec1.session_id                          AS BlockedSessionId
                    ,h1.TEXT                                 AS BlockedSQLText
                    ,h2.TEXT                                 AS BlockingSQLText
              FROM sys.dm_tran_locks AS tl
              INNER JOIN sys.databases db
                ON db.database_id = tl.resource_database_id
              INNER JOIN sys.dm_os_waiting_tasks AS wt
                ON tl.lock_owner_address = wt.resource_address
              INNER JOIN sys.dm_exec_connections ec1
                ON ec1.session_id = tl.request_session_id
              INNER JOIN sys.dm_exec_connections ec2
                ON ec2.session_id = wt.blocking_session_id
              LEFT OUTER JOIN master.dbo.sysprocesses sp
                ON SP.spid = wt.blocking_session_id
              CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
              CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2;
         END
     ELSE IF @OutType='Table'
        BEGIN
     
              INSERT INTO [Maint].[BlockingSQLHistory]
              SELECT GETDATE()                               AS RecordTime
                    ,db.name                                 AS DatabaseName    
                    ,wt.blocking_session_id                  AS BlockingSessesionId
                    ,sp.program_name                         AS ProgramName
                    ,COALESCE(sp.LOGINAME, sp.nt_username)   AS UserName    
                    ,ec1.client_net_address                  AS ClientIpAddress
                    ,wt.wait_type                            AS WaitType                    
                    ,ec1.connect_time                        AS BlockingStartTime
                    ,wt.WAIT_DURATION_MS/1000                AS WaitDuration
                    ,ec1.session_id                          AS BlockedSessionId
                    ,h1.TEXT                                 AS BlockedSQLText
                    ,h2.TEXT                                 AS BlockingSQLText
              FROM sys.dm_tran_locks AS tl
              INNER JOIN sys.databases db
                ON db.database_id = tl.resource_database_id
              INNER JOIN sys.dm_os_waiting_tasks AS wt
                ON tl.lock_owner_address = wt.resource_address
              INNER JOIN sys.dm_exec_connections ec1
                ON ec1.session_id = tl.request_session_id
              INNER JOIN sys.dm_exec_connections ec2
                ON ec2.session_id = wt.blocking_session_id
              LEFT OUTER JOIN master.dbo.sysprocesses sp
                ON SP.spid = wt.blocking_session_id
              CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
              CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2;
         END
      ELSE IF @OutType='Email'
         BEGIN
 
            SET @HtmlContent =
               N'<head>' 
             + N'<style type="text/css">h2, body {font-family: Arial, verdana;} table{font-size:11px; border-collapse:collapse;} td{ border:1px solid black; padding:3px;} th{background-color:#99CCFF;}</style>'
             + N'<table border="1">' 
             + N'<tr>
                 <th>DatabaseName</th>
                 <th>BlockingSessesionId</th>
                 <th>ProgramName</th>
                 <th>UserName</th>
                 <th>ClientIpAddress</th>
                 <th>WaitType</th>
                 <th>BlockingStartTime</th>
                 <th>WaitDuration</th>
                 <th>BlockedSessionId</th> 
                 <th>BlockedSQLText</th>
                 <th>BlockingSQLText</th>
                </tr>' +
             CAST ( 
                    (SELECT db.name                                  AS TD, ''
                           ,wt.blocking_session_id                   AS TD, ''
                           ,sp.program_name                          AS TD, ''
                           ,COALESCE(sp.LOGINAME, sp.nt_username)    AS TD, ''
                           ,ec1.client_net_address                   AS TD, ''
                           ,wt.wait_type                             AS TD, ''            
                           ,ec1.connect_time                         AS TD, ''
                           ,wt.WAIT_DURATION_MS/1000                 AS TD, ''
                           ,ec1.session_id                           AS TD, ''
                           ,h1.TEXT                                  AS TD, ''
                           ,h2.TEXT                                  AS TD, ''
 
                    FROM sys.dm_tran_locks AS tl
                    INNER JOIN sys.databases db 
                            ON db.database_id = tl.resource_database_id
                    INNER JOIN sys.dm_os_waiting_tasks AS wt  
                            ON tl.lock_owner_address = wt.resource_address
                    INNER JOIN sys.dm_exec_connections ec1 
                            ON ec1.session_id = tl.request_session_id
                    INNER JOIN sys.dm_exec_connections ec2 
                            ON ec2.session_id = wt.blocking_session_id
                    LEFT OUTER JOIN master.dbo.sysprocesses sp
                            ON SP.spid = wt.blocking_session_id
                    CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
                    CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2
                
               FOR XML PATH('tr'), TYPE 
                ) AS NVARCHAR(MAX) ) +
                N'</table>'
 
 
                IF @HtmlContent  IS NOT NULL
                 
                BEGIN
 
                    EXEC msdb.dbo.sp_send_dbmail     
                            @profile_name = @ProfileName    ,     
                            @recipients   = @RecipientsLst    ,     
                            @subject      = @EmailSubject    ,     
                            @body         = @HtmlContent    ,   
                            @body_format  = 'HTML' ; 
 
                END
        END
 
END
GO

最后在数据库新建一个作业,调用该存储过程,然后在某段时间启用作业监控数据库的阻塞情况,作业的执行频率是个比较难以定夺的头痛问题,具体要根据系统情况来决定,我习惯2分钟执行一次。

最后,这个脚本还有一个问题,如果阻塞或被阻塞的SQL语句是某个存储过程里面的一段脚本,显示的SQL是整个存储过程,而不是正在执行的SQL语句,目前还没有想到好的方法解决这个问题。我目前手工去查看阻塞情况,如果非要查看存储过程里面被阻塞的正在执行的SQL,一般结合下面SQL语句查看(输入阻塞或被阻塞会话ID替代@sessionid)

SELECT   [Spid] = er.session_id 
        ,[ecid] 
        ,[Database] = DB_NAME(sp.dbid) 
        ,[Start_Time]
        ,[SessionRunTime]    = datediff(SECOND, start_time,getdate())    
        ,[SqlRunTime]=     RIGHT(convert(varchar, 
                                 dateadd(ms, datediff(ms, sp.last_batch, getdate()), '1900-01-01'), 
                            121), 12)  
        ,[HostName]  
        ,[Users]=COALESCE(sp.LOGINAME, sp.nt_username)
        ,[Status] = er.status 
        ,[WaitType] = er.wait_type 
        ,[Waitime] = er.wait_time/1000   
        ,[Individual Query] = SUBSTRING(qt.text, er.statement_start_offset / 2,
                                       ( CASE WHEN er.statement_end_offset = -1
                                              THEN LEN(CONVERT(NVARCHAR(MAX), qt.text))
                                                   * 2
                                              ELSE er.statement_end_offset
                                         END - er.statement_start_offset ) / 2) 
        ,[Parent Query] = qt.text 
        ,[PROGRAM_NAME] = program_name 
FROM    sys.dm_exec_requests er
        INNER JOIN sys.sysprocesses sp ON er.session_id = sp.spid
        CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) AS qt
WHERE   session_Id = @sessionid;

posted @ 2015-08-19 17:31 Learning hard 阅读(...) 评论(...) 编辑 收藏