The average time take of executeQuery() test shows significant difference between version 19.11 and 21.0.
https://github.com/graphql-java/graphql-java/blob/v21.0/src/test/java/benchmark/BenchMark.java#L54
https://github.com/graphql-java/graphql-java/blob/v19.11/src/test/java/benchmark/BenchMark.java#L55

I've tested it by changing the NUMBER_OF_FRIENDS value to 10000, which is 10 times of the default setting in the benchmark test code.

Query used in the benchmark code

{
  hero {
    name
    friends {
      name
      friends {
        name
      }
    }
  }
}

Object used in the benchmark code

{
    "name": "r2d2",
    "friends": [
        {
            "name": "friend1",
            "friends":[],
        },
        {
            "name": "friend2",
            "friends":[],
        },
        ...
        // 10000 friends
    ]
}

Result by graphql-java versions

Is it possible to apply the performance improvements that were done in 21.0 version to the 19.11 version?

I think the difference is not from java version (graphql-java 21.0 is using java 17) since the improvement is quite huge.

Thank you!