Allow to limit the execution time of GraphQL queries

[ujibang]

Brief overview

Allow to limit the GraphQL queries execution by setting a time limit.

If a query execution time exceeds the time limit, 408 Request timeout should be returned with following error message:

{
  "errors": [
    {
      "message": "Maximum query time limit of 20ms exceeded",
      "extensions": { "classification": "ExecutionAborted" }
    }
  ]
}

Rationale

Avoid GraphQL queries that consume too much resources.

Detailed documentation

The GraphQL configuration parameter query-time-limit specifies the time limit in milliseconds for processing queries. Set to 0 for no time limit.

Example:

The following command starts RESTHeart overriding the configuration paramenter /graphql/query-time-limit setting a limit of 10s for GraphQL queries execution:

$  RHO="/graphql/query-time-limit->10000" java -jar core/target/restheart.jar

[ujibang]

Done in 7.6.3