In a recent test run against REP-2771’s development branch for time-series support, I saw this error:

(NamespaceExists) namespace test.timeseries_insert already exists, but is a view on test.system.buckets.timeseries_insert rather than test.

The verbiage seems a bit frustrated, and there really shouldn’t be actual namespace conflicts at that point in a mongosync CI run since each namespace gets exactly 1 `create`, and nothing else alters the destination cluster at that time.

It looks like what happened was that an election happened midway through creation of a time-series collection (via the public API, not creating buckets+view directly), and maybe that confused things afterward.

One potential workaround is for mongosync to create the buckets & view separately; I haven’t yet investigated that change to see if it’ll work.