Why is my SQL Server reporting CLR_AUTO_EVENT waits when I don't even use SQL CLR?

Question

When I run this query, I see high wait time for CLR_AUTO_EVENT:

SELECT
    *
FROM
    sys.dm_os_wait_stats
WHERE
    wait_type IN
    (
        'CLR_AUTO_EVENT',
        'CLR_CRST',
        'CLR_JOIN',
        'CLR_MANUAL_EVENT',
        'CLR_MEMORY_SPY',
        'CLR_MONITOR',
        'CLR_RWLOCK_READER',
        'CLR_RWLOCK_WRITER',
        'CLR_SEMAPHORE',
        'CLR_TASK_START',
        'CLRHOST_STATE_ACCESS',
        'ASSEMBLY_LOAD',
        'FS_GARBAGE_COLLECTOR_SHUTDOWN',
        'SQLCLR_APPDOMAIN',
        'SQLCLR_ASSEMBLY',
        'SQLCLR_DEADLOCK_DETECTION',
        'SQLCLR_QUANTUM_PUNISHMENT'
    )
ORDER BY
    wait_time_ms DESC,
    wait_type ASC;

In a related question What is the SQLCLR wait type in Activity Monitor within SQL Server Management Studio (SSMS)? , I read that it appears when running .NET managed code within SQL Server.

However, I don't think I'm using any of that. When I execute EXEC sp_configure 'clr enabled', I see:

It looks to me like it's not even enabled. Can anybody please explain what's going on?

PS: I'm running SQL Server 2017 Developer Edition (14.0.3026.27).

Answer 1

SQL Server uses CLR internally for several features, and these waits track CLR background threads just sitting around waiting on a ManualResetEvent or a AutoResetEvent. According to High waits on CLR_MANUAL_EVENT and CLR_AUTO_EVENT these are background waits (ie the wait time is not happening to user sessions), and can safely be ignored unless you have unsafe CLR code using these events directly.