How to use ExecutorService in Kubernetes PODs

Question

I have requirement to call REST API from an OSGI service which is running in K8 pods. For this I am thinking to use Java Async way by using Executor service.

But I am not sure how my code will work in the Kubernetes Cluster when I use my own Threadpool size

 ExecutorService executorService = Executors.newFixedThreadPool(10)

 HttpClient.newBuilder()
            .executor(executorService)
            .build()
            .sendAsync(request, HttpResponse.BodyHandlers.ofString())
            .thenApplyAsync(new Function<HttpResponse<String>, GraphQlResponse>() {
                public GraphQlResponse apply(HttpResponse<String> response) {
                    // some code
                }
            }, executorService);

At the moment, I do not know the resource management configuration of PODs.

Can it cause performance issue?