// Reads may not be entirely up-to-date, but they will always see the
// history of changes moving forward, the data read will be consistent
// across sequential queries in the same session, and modifications made
// within the session will be observed in following queries (read-your-writes).
// http://godoc.org/labix.org/v2/mgo#Session.SetMode.
mongoSession.SetMode(mgo.Monotonic, true)