When using a _type: MongoDBCollection, parameters "sort", "field", "skip", and "limit" do not seem to get sent along with the query from the objectserver:
URL (GET) sent to carbon server and resulting log line (no ntoreturn, returns all documents with {"published": true}):
http://localhost:8885/events?query={"published":true}&limit=1
2016-06-02T15:41:18.140-0700 I COMMAND [conn386] command mongolab-status.public-status-events command: find { find: "public-status-events", filter: { published: true }, projection: {} } planSummary: COLLSCAN keysExamined:0 docsExamined:3 cursorExhausted:1 keyUpdates:0 writeConflicts:0 numYields:0 nreturned:2 reslen:758 locks:{ Global: { acquireCount: { r: 2 } }, MMAPV1Journal: { acquireCount: { r: 1 } }, Database: { acquireCount: { r: 1 } }, Collection: { acquireCount: { R: 1 } } } protocol:op_query 0ms
shell command and resulting log line (ntoreturn is 1, returns 1 document):
db['public-status-events'].find().limit(1)
2016-06-02T14:41:06.736-0700 I QUERY [conn392] query mongolab-status.public-status-events planSummary: COLLSCAN ntoreturn:1 ntoskip:0 keysExamined:0 docsExamined:1 cursorExhausted:1 keyUpdates:0 writeConflicts:0 numYields:0 nreturned:1 reslen:395 locks:{ Global: { acquireCount: { r: 2 } }, MMAPV1Journal: { acquireCount: { r: 1 } }, Database: { acquireCount: { r: 1 } }, Collection: { acquireCount: { R: 1 } } } 0ms