I am constantly getting Azure SQL Server sessions with (blocked by) "Blk By" column of -5.
What could this session be please? I have searched for negative number SPID and I can see information for -2, -3, -4 but not for -5.
(I have removed identifiable information for hostname, login dbname columns)
Copied below is a listing from sp_who2
According to the documentation for blocking_session_id
-5 = Session ID of the blocking latch owner could not be determined because it is not tracked for this latch type (for example, for an SH latch).
Edit: I came across this from a Microsoft engineer. The bit I found interesting:
A blocking session id of -5 alone does not indicate a performance problem. The addition of -5 is just an indication that the session is waiting on an asynchronous action to complete where-as prior to the addition, the same session wait would have showed blocking session = 0 but was still in a wait state.
