MongoDB Ruby driver and mongoS

Question

I am trying to use the MongoDB Ruby driver to pull information from a cluster via mongoS. Here is what I've done.

@mongo_client = Mongo::Connection.new('mongoshost', 27320)
@db = @mongo_client.db("thedatabase")
@auth = @db.authenticate("username", "password")
if(@mongo_client)
  print "Successfully connected to mongos\n"
else
  print "Connection failed"
end
if(@auth == true)
  print "Auth successful\n"
else
print "Auth failed"
  end
collection = @db.collection("thecollection")
puts collection.find.to_a

When I run this, everything works up until the point that it tries to print the documents in the collection. Here's what my output looks like:

C:\Code\whatever>ruby getdata.rb
Successfully connected to mongos
Auth successful
C:/Ruby200/lib/ruby/gems/2.0.0/gems/bson-1.9.2/lib/bson/bson_c.rb:24:in `deseria
lize': time must be positive (ArgumentError)
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/bson-1.9.2/lib/bson/bson_c.rb:2
4:in `deserialize'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/networkin
g.rb:223:in `read_documents'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/networkin
g.rb:169:in `receive'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/networkin
g.rb:133:in `receive_message'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:497:in `block in send_initial_query'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/util/logg
ing.rb:55:in `block in instrument'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/util/logg
ing.rb:20:in `instrument'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/util/logg
ing.rb:54:in `instrument'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:493:in `send_initial_query'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:478:in `refresh'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:124:in `next'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:290:in `each'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:314:in `to_a'
        from C:/Ruby200/lib/ruby/gems/2.0.0/gems/mongo-1.9.2/lib/mongo/cursor.rb
:314:in `to_a'
        from getdata.rb:27:in `<main>'

The "time must be positive" error had a few search results, but nothing that helped me figure out what the issue is. One of the fields in these documents does hold a negative number for a date, but I'm not sure why that's an issue since it's reading it and not writing (For example, one of the fields looks like so: {"md" : Date(-62135596800000)})

Is this an issue with the driver, is my code bad, or do I need to figure this out in another manner? I'm pretty new to ruby so any help would be appreciated!

Answer 1

Your data is bad as you have already noted. The problem is that the driver is trying to expand the date value ( which is really just a number internally to mongo within a BSON timestamp field ) into a real DateTime object.

When it tries to do this on read, the number is invalid an the inflation fails. If you fix the date value the problem will be corrected.

Note: If you do this in the shell use the ISOate helper to put a correct value in. If you use code then use a DateTime object. Don't use strings as you will mess your data up further.