How to migrate REST APIs to GraphQL Apollo Federation

Question

Planning to migrate my PHP APIs to Graphql using Apollo Federation. After a bit of research, I see it is done using the following way:

My questions are:

1. Is there any better way to create the federated services so it is not a separate layer (1 for each REST API)? Maybe something close to the previous schema stitching approach where all can sit in one place and be stitched together at the end (instead of a specific federated layer for each service).

2. If this is the recommended way, how do I deploy this infrastructure? From the diagram, does it mean I have 5 instances running to cover all of the services?

3. Is it recommended to run Gateway and Federated services all inside one instance (from diagram - 3 servers running in one instance)?

question from:https://stackoverflow.com/questions/65932655/how-to-migrate-rest-apis-to-graphql-apollo-federation

Answer 1

Let me know if it helps.

1. Federated services are great when you want to break the monolithic structure of the non federated implementation of apollo server. It can be designed by incorporating the micro-service best practices. Instead of blindly having one federated service per rest endpoint, you can have federated services based on the functionality the service is suppose to take care. One service can call multiple rest endpoit. This would provide you better control on scaling, securing and managing services at infrastructure level. An example can be as simple as amazon where item browsing hits will be way more than buying transactions. In this case you can have one federated service which provides browsing data where as another one can for managing transactions. Then you can scale one to multiple instance to handle user load and have additional security in place for the one hadnling transactions.

2 & 3. Yes you would need to have deploy all the components separately. I would recomend to have all the services in the same VPC cluster so that you don't have to worry about network layer security. If the services are deployed across multiple clusters, it will be adding handling firewall and https/tls for every request, which would cause unnecssaery delay becuase of network call. Although it would be in milliseconds but can be easily avoided.