Using MongoDB and Neo4j together

Question

I am starting a new project and I am looking at using MongoDB as the document storage facility and Neo4j as the mechanism to map relationships between documents and then I want to expose the results of my queries via rest API. What would one say are the advantages and disadvantages of doing it this manner? Are there any better ways of achieving this perhaps using a different NoSQL document store? Are there any examples one could find online where someone has tried to do something similar?

Answer 1

I have been thinking about using these two together for a while because my data is already in mongodb. But I don't want to add one more DB top of the existing architecture, because addition of neo4j will require more resources e.g. memory, diskspace and not to mention time invested in maintaining 2 DBs.

Another problem which I can think of is when you shard your data with mongodb, you'll also have to manage your neo4j data w.r.t. these new shards. Scaling in neo4j is done through clusters and it is a part of enterprise edition which is commercial.

I did further research and found out that OrientDB can store the data as documents and its a graph db.

Another way is building the relationships in MongoDB itself and write your logic on top of that and expose this logic through a REST API.

Answer 2

You might be interested in the Neo4j Doc Manager for Mongo Connector. It's an extension to the Mongo Connector project that allows for real time one way synchronization of data from MongoDB to Neo4j. Documents inserted in MongoDB are converted to a property graph and automatically inserted into Neo4j. The collection and fields to be synched from Mongo to Neo4j can be configured.

The idea here is to facilitate using Neo4j and MongoDB together in a single application without having to write code in the application layer to sync data.