SqlServer 服务器CPU升高因为用户未注销引起的explorer.exe CPU升高

今天看监控，发现服务器CPU比往常高几乎一倍，发现是前一天开始升高的。

进去服务器查看系统及SqlServer最近30分钟的CPU使用情况（只是取一段时间看看CPU）

DECLARE @ts_now bigint = (SELECT cpu_ticks/(cpu_ticks/ms_ticks)  
FROM sys.dm_os_sys_info WITH (NOLOCK));  
SELECT TOP(30) SQLProcessUtilization AS [SQL Server Process CPU Utilization],  
SystemIdle AS [System Idle Process],  
100 - SystemIdle - SQLProcessUtilization AS [Other Process CPU Utilization]
,DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) AS [Event Time]  
FROM (
	SELECT record.value('(./Record/@id)[1]', 'int') AS record_id
	,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int') AS[SystemIdle]
	,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]','int') AS [SQLProcessUtilization], [timestamp]  
	FROM (
		SELECT [timestamp], CONVERT(xml, record) AS [record]  
		FROM sys.dm_os_ring_buffers WITH (NOLOCK)  
		WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR'  
		AND record LIKE N'%<SystemHealth>%'
	) AS x  
) AS y  
ORDER BY record_id DESC OPTION (RECOMPILE);  

拷贝结果到Excel中以图像查看

可以看到，SqlServer的CPU在40%~50%的范围，跟往常一样，不变，不是SqlServer引起的CPU升高。

打开任务管理器按CPU使用比例排序，发现 explorer.exe占用CPU 10%~30%. 

explorer.exe 一般情况下都为0，偶尔才大于1%，可以发现主要是explorer.exe 的影响.

点击 “用户” ，发现有一个不活动的用户并未断开，直接右键 注销该用户。

完后发现， explorer.exe 的CPU已经明显下降了!

过些时间看看监控，CPU下来了。explorer.exe的CPU升高，主要还是用户未注销。