关于SQL Server会创建多少个工作线程的详细信息,你可以参考文档Configure the max worker threads Server Configuration Option. 当一个查询去执行时,SQL Server会决定需要多少个线程(请见Paul Whtile的博客Parallel Execution Plans – Branches and Threads),并且决定为线程池(thread pool)保留多少个线程。 如果没有足够...
g_hevents[i] = CreateEvent(NULL, FALSE, FALSE, NULL); PTP_WAIT waits[g_nConnection]; for(int i = 0; i < g_nConnection; i++) { waits[i] = CreateThreadpoolWait(&WaitCallBack, reinterpret_cast<PVOID>((UINT_PTR)i), NULL); SetThreadpoolWait(waits[i], g_hevents[i], NULL); ...
当一个session要select一些数据,但是刚刚好,这些数据并没有在buffer pool 中,那么sql server 就会分配一些缓存这些缓存是属于buffer pool 的,用来存放从磁盘读取出来的数据,在读取的时候都会给这些缓存上latch(可以看成是锁)。当存在io瓶颈的时候,那么磁盘上的数据不能立即读到buffer pool 中就会出现等待latch的情况。
-- global server wait stats (completed waits only) SELECT wait_type, waiting_tasks_count, (wait_time_ms - signal_wait_time_ms) AS wait_time_ms, signal_wait_time_ms, wait_time_ms AS raw_wait_time_ms FROM sys.dm_os_wait_stats WHERE waiting_tasks_count > 0 OR wait_time_ms...
The THREADPOOL waits might then be a result of some infrequent activity by some application or utility that tries to perform a concurrent activity in each of the databases - SQL Server does not have enough threads to run even one task in each database at the same time - and the lack of...
当一个session要select一些数据,但是刚刚好,这些数据并没有在buffer pool 中,那么sql server 就会分配一些缓存这些缓存是属于buffer pool 的,用来存放从磁盘读取出来的数据,在读取的时候都会给这些缓存上latch(可以看成是锁)。当存在io瓶颈的时候,那么磁盘上的数据不能立即读到buffer pool 中就会出现等待latch的情况...
THREADPOOL当某任务正在等待工作线程运行时出现。 这可能指示最大工作线程数设置过低,或批处理执行时间过长,从而减少可满足其他批处理的工作线程数。 TIMEPRIV_TIMEPERIOD在扩展事件计时器进行内部同步期间出现。 TRACEWRITE当 SQL 跟踪行集跟踪提供程序等待可用缓冲区或可处理事件...
This wait means server is out of worker threads and can’t bind the new connection request to a worker thread. In most cases the cause of THREADPOOL waits is that existing workers created by SQL Server are tied up with a long...
确定具体的方法论用于SQL Server故障诊断是件很难的事情。因为根据问题和环境的不同,解决方法也不一样。一个准确的故障诊断,不仅是收集各种信息,而且要明白它们的含义。千万不要只见树木不见森林。 作者通过一个简单的诊断示例,演示基本的方法和借助的工具: ...
waits=\"1293727\" averageWaitTime=\"24668922\" maxWaitTime=\"583\"/><wait waitType=\"THREADPOOL\" waits=\"5286\" averageWaitTime=\"4522428\" maxWaitTime=\"7982\"/><wait waitType=\"LCK_M_S\" waits=\"1\" averageWaitTime=\"614\" maxWaitTime=\"614\"/><wait waitType=\"...