supergraphq

One Graph Service with graphql federation v2. We're using Apollo Federation which is an open source architecture for building a distributed graph. With Apollo Federation, we're able to implement GraphQL in a microservice architecture. It’s designed to replace schema stitching and solve pain points such as coordination, separation of concerns, and brittle gateway code.

Sub Graphs

Supergraph is composed by the following sub graphs:

Search Domain Graph Service

Document Domain Graph Service

Running

• Clone both subgraphs listed above.
• Make sure that all subgraphs are running.
• Run supergraph:

yarn dev

Example

This query should fetch data from all subgraphs:

query Search($artifact: String!, $q: String!) {
  search(artifact: $artifact, q: $q) {
    id
    documentId
    title
    body
    relatedDocument {
      documentId
      title
      # available only in documents subgraph
      meritDecision
      mandatoryPrecedent
      readingTime
    }
  }
}

# variables
{
 "artifact": "JURISPRUDENCIA",
 "q": "danos morais"
}

FAQ

• How it works when subgraph schema changes in production? Supergraph needs to redeploy? Everytime that the schema of any subgraph changes, supergraph must run schema composition. The new schema will be available in the graph after this process. See more: https://www.apollographql.com/docs/federation/federated-types/composition/

• What happens when a subgraph is down? If any subgraph is down, the supergraph application will raise an error when it starts: Error: Couldn't load service definitions for "search" at http://localhost:4001/graphql: request to http://localhost:4001/graphql failed. When supergraph is already running and subgraph crashes for some reason, any request that it's handled by the crashed subgraph will fail.

• Is it any performance issues? A note on performance: Query Planning and Execution adds a ~10ms overhead in the worst case. This includes the compute for building the query plan, as well as the deserialization of DGS responses and the serialization of merged gateway response.

• How does it work with Relay subgraph? It doesnt work.

Docs

GraphQL Principle.

Apollo Federation.

Netflix API with GraphQL Federation.