Moped::Errors::OperationFailure failed with error "no such cmd

Question

I recently upgraded from mongoid 2.0.2 to mongoid 3 with rails 3.2.12 and ruby 1.9.3 .

Following issue comes when save command excutes => @new_node.save


  Moped::Errors::OperationFailure (The operation: #<Moped::Protocol::Command
      @length=366
      @request_id=30
      @response_to=0
      @op_code=2004
      @flags=[:slave_ok]
      @full_collection_name="campus_dev.$cmd"
      @skip=0
      @limit=-1
      @selector={:aggregate=>"nodes", :pipeline=>[{"$match"=>{"parent_id"=>"51382df8851d1912b7000009", "_id"=>{"$ne"=>"513f24952f1feda4bc000002"}, "position"=>{"$nin"=>[nil]}}}, {"$group"=>{"_id"=>"position", "count"=>{"$sum"=>1}, "max"=>{"$max"=>"$position"}, "min"=>{"$min"=>"$position"}, "sum"=>{"$sum"=>"$position"}, "avg"=>{"$avg"=>"$position"}}}]}
      @fields=nil>
    failed with error "no such cmd"):
      app/controllers/nodes_controller.rb:37:in `create'

Same error reported here as well: https://github.com/mongoid/moped/issues/160 — Haseeb Khan, Mar 12 '13 at 16:51
Sure you are running also the newest Version of your MongoDB? — bMalum, Aug 03 '15 at 10:37

score 1 · Answer 1 · answered Sep 09 '15 at 23:03

You didn't mention also upgrading MongoDB version to the latest (at that time).

If you were pointing at an older MongoDB server that didn't recognize the "aggregate" command, then you would get exactly this error.

All instances of similar errors seem to have been pointing at older mongod process.

Moped::Errors::OperationFailure failed with error "no such cmd

1 Answers1