Occasionally, evergreen tasks will fail on session prose test #14: "Implicit sessions only allocate their server session after a successful connection checkout".

[2022/12/08 19:23:22.950] === RUN   TestSessions/14._implicit_session_allocation

12024
[2022/12/08 19:23:22.950]     sessions_test.go:473: expected one session across all 8 operations for at least 1/5 retries, got: 2

 
Here is an example of such a failure.

There is a note in the prose test concerning this rare failure:

Note that it's possible, although rare, for >1 server session to be used because the session is not released until after the connection is checked in.

Considering increasing the threshold from 5 to 10?