The documents in healthlog collection (local.system.healthlog) are an IDL defined type HealthLogEntry. The documents have an optional namespace field, so we'll need a way to track the tenantId when the namespace is not empty. As a part of this ticket we'll need to decide how to store the tenantId in this case - should we make this collection per tenant? Store the tenantId in a separate field similar to the oplog? Or, continue to prefix similar to the _mdb_catalog? Then, we'll need to change the places we serialize and deserialize this type to behave accordingly.