MongoDB V3.2
Upgraded the following the gems:
Ruby Mongo Driver from 1.11.1 to 2.10.4 + dependencies Replaced MongoMapper 0.13.1 with Mongoid 5.4.1 + dependencies
After these changes, I noticed immediately that any collections that were placed in an additional module (FolderModuleName::ClassName) that could display data in MongoMapper would no longer display any data.
The only collections that would display data would be those without any modules for example a class that looked like this class DataClass.
I was able to figure out the issue by using the rails console and connecting to my database using the ruby mongo driver. (https://docs.mongodb.com/ruby-driver/master/quick-start/)
client = Mongo::Client.new([ '127.0.0.1:27017' ], :database => 'dbname')
db = client.database
db.collections # returns a list of collection objects
db.collection_names # returns a list of collection names
Using db.collection_names in the rails console I was able to see that any collection with a module was saved like this:
module_name.collection_name
After my upgrade the only collections names with modules I could read were:
module_name_collection_name
With this information, I added the following code to the ruby models affected:
store_in collection: 'module_name.collection_name'
This fixed my issue.
The reason collections without modules could be read without using the code above is because the collection names were simply stored as:
collection_name
Adding 'store in' in that case would just be redundant.