--CPU相关视图 SELECT * FROM sys.dm_os_sys_info SELECT * FROM sys.dm_exec_sessions SELECT * FROM sys.sysprocesses SELECT * FROM sys.dm_os_tasks SELECT * FROM sys.dm_os_workers SELECT * FROM sys.dm_os_threads SELECT * FROM sys.dm_os_schedulers SELECT * FROM sys.dm_os_memory_objects SELECT * FROM sys.dm_os_nodes SELECT * FROM sys.dm_os_memory_nodes exec sp_configure ‘max degree of parallelism‘--系统默认并行度 exec sp_configure ‘cost threshold for parallelism‘ --并发阈值 exec sp_configure ‘max worker threads‘--系统最大工作线程数 exec sp_configure ‘affinity mask‘ --CPU关联 --数据库系统 cpu，线程 数量 select max_workers_count,scheduler_count,cpu_count,hyperthread_ratio ,(hyperthread_ratio/cpu_count) AS physical_cpu_count ,(max_workers_count/scheduler_count) AS workers_per_scheduler_limit from sys.dm_os_sys_info --执行的线程所遇到的所有等待的相关信息 SELECT TOP 10 wait_type,waiting_tasks_count,signal_wait_time_ms FROM sys.dm_os_wait_stats ORDER BY signal_wait_time_ms DESC --正在等待某些资源的任务的等待队列的信息 SELECT TOP 10 wait_type,wait_duration_ms,session_id,blocking_session_id FROM sys.dm_os_waiting_tasks ORDER BY wait_duration_ms DESC --CPU或调度器当前分配的工作情况 SELECT scheduler_id,cpu_id,status,is_idle ,current_tasks_count AS 当前任务数 --在等待或运行的任务 ,runnable_tasks_count AS 等待调度线程数 --已分配任务并且正在可运行队列中 ,current_workers_count AS 当前线程数 --相关或未分配任何任务的工作线程 ,active_workers_count AS 活动线程数 --在运行、可运行或挂起 ,work_queue_count AS 挂起任务数 --等待工作线程执行 FROM sys.dm_os_schedulers WHERE scheduler_id < 255 --当前线程数 select COUNT(*) as 当前线程数 from sys.dm_os_workers --非SQL server create的threads select * from sys.dm_os_threads where started_by_sqlservr=0 --即scheduler_id > 255 --有task 等待worker去执行 select * from sys.dm_os_tasks where task_state=‘PENDING‘ --计数器 select * from sys.dm_os_performance_counters where object_name=‘SQLServer:SQL Statistics‘ select * from sys.dm_os_performance_counters where object_name=‘SQLServer:Plan Cache‘ ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- --1. 实例累积的信号（线程/CPU）等待比例是否严重 SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats WITH (NOLOCK) OPTION (RECOMPILE); --2. SqlServer各等待类型的线程等待信息 SELECT TOP 20 wait_type,waiting_tasks_count ,wait_time_ms,signal_wait_time_ms ,wait_time_ms - signal_wait_time_ms AS resource_wait_time_ms ,CONVERT(NUMERIC(14,2),100.0 * wait_time_ms /SUM (wait_time_ms ) OVER( )) AS percent_total_waits ,CONVERT(NUMERIC(14,2),100.0 * signal_wait_time_ms /SUM (signal_wait_time_ms) OVER( )) AS percent_total_signal_waits ,CONVERT(NUMERIC(14,2),100.0 * ( wait_time_ms - signal_wait_time_ms )/SUM (wait_time_ms ) OVER( )) AS percent_total_resource_waits FROM sys .dm_os_wait_stats WHERE wait_time_ms > 0 ORDER BY percent_total_signal_waits DESC --3. 闩锁(latch)等待的信息 select top 20 latch_class,waiting_requests_count,wait_time_ms,max_wait_time_ms from sys.dm_os_latch_stats order by wait_time_ms desc --使用最多处理器时间的用户数据库 ;WITH DB_CPU_Stats AS ( SELECT DatabaseID, DB_Name(DatabaseID) AS [DatabaseName], SUM(total_worker_time) AS [CPU_Time_Ms] FROM sys.dm_exec_query_stats AS qs CROSS APPLY (SELECT CONVERT(int, value) AS [DatabaseID] FROM sys.dm_exec_plan_attributes(qs.plan_handle) WHERE attribute = N‘dbid‘) AS F_DB GROUP BY DatabaseID) SELECT ROW_NUMBER() OVER(ORDER BY [CPU_Time_Ms] DESC) AS [row_num], DatabaseName , [CPU_Time_Ms], CAST([CPU_Time_Ms] * 1.0 / SUM([CPU_Time_Ms])OVER() * 100.0 AS DECIMAL(5,2)) AS [CPUPercent] FROM DB_CPU_Stats WHERE DatabaseID > 4 -- system databases AND DatabaseID <> 32767 -- ResourceDB ORDER BY row_num OPTION (RECOMPILE); --缓存中最耗CPU的语句 select total_cpu_time,total_execution_count,number_of_statements,[text] from ( select top 20 sum(qs.total_worker_time) as total_cpu_time, sum(qs.execution_count) as total_execution_count, count(*) as number_of_statements, qs.plan_handle from sys.dm_exec_query_stats qs group by qs.plan_handle order by total_cpu_time desc ) eqs cross apply sys.dm_exec_sql_text(eqs.plan_handle) as est order by total_cpu_time desc /*【ask 让出scheduler ：worker yielding】 1. worker读数据页超过4ms 2. 64k结果集排序 3. compile或recompile（常有） 4. 客户端不能及时取走结果集 5. batch 的每个操作完整 */ --当前正在执行的语句 SELECT der.[session_id],der.[blocking_session_id], sp.lastwaittype,sp.hostname,sp.program_name,sp.loginame, der.[start_time] AS ‘开始时间‘, der.[status] AS ‘状态‘, der.[command] AS ‘命令‘, dest.[text] AS ‘sql语句‘, DB_NAME(der.[database_id]) AS ‘数据库名‘, der.[wait_type] AS ‘等待资源类型‘, der.[wait_time] AS ‘等待时间‘, der.[wait_resource] AS ‘等待的资源‘, der.[reads] AS ‘物理读次数‘, der.[writes] AS ‘写次数‘, der.[logical_reads] AS ‘逻辑读次数‘, der.[row_count] AS ‘返回结果行数‘ FROM sys.[dm_exec_requests] AS der INNER JOIN master.dbo.sysprocesses AS sp on der.session_id=sp.spid CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id]>50 AND session_id<>@@SPID AND DB_NAME(der.[database_id])=‘platform‘ ORDER BY [cpu_time] DESC --实例级最大的瓶颈 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
