Moved from: bobsql.com
There are a variety of posts talking about the black box recorder (XEL Health Session) explaining what the recorder is and does: https://blogs.msdn.microsoft.com/psssql/2012/03/08/sql-server-2012-true-black-box-recorder/
This week I ran into niche behavior while looking at the health session output. While it is unlikely to have any impact on your server the output during a SQL Server shutdown could mislead you.
The health session runs on a preemptive, above normal, priority thread. This design allows the health monitor thread to provide rich output even when the overall server is under stress. The session allocates memory and initializes all the