Implementation and performance analysis of GraphQL schema delegation

GraphQL schema delegation is the name of the architectural pattern of delegating queries from one GraphQL server to another. This project aimed to find different methods and techniques for implementing schema delegation, implement one of them and evaluate the performance. Few methods were found, and the npm library graphql-tools was seemingly the only dedicated tool available to implement schema delegation. One GraphQL server was automatically generated with a tool called Hasura. graphql-tools was used to implement another server, delegating to the automatically generated server. Tests were run with the help of the resources from the Linköping GraphQL benchmark. The automatically generated server served as a baseline. Test results found that, overall,the delegating server had significantly worse performance than the generated server. There were, however, some test results where the servers had similar performance. We conclude that there seem to be situations where graphql-tools perform well and suggest methods to increase the performance in areas where graphql-tools do not performwell. We also suggest implementing GraphQL schema delegation without the use of any tools