Reported by jmo+mms@john-morales.com :

Mirrored reads (on by default since 4.4) result in quite few query stats entries on the secondaries. I suppose eventually all the access patterns on the primary will be observed as a queryStats entries on the secondaries, too. And further, these mirrored entries have the client metadata as mongod's internal client, rather than the customer's driver client metadata.

I suppose this could all be fine and expected behavior. From analysis point of view, they may not be the most interesting entries to include with analysis - but on the other hand, they do seem to be easily identifiable, so if nothing else our GTM/DW could just filter these out.

I think not having the customer's client metadata but rather mongod's client driver name of 'NetworkInterfaceTL-MirrorMaestro' was the main thing that caught my attention.