rest-clients

REST clients performance test

Prerequisites

Java 13+, Gradle 6 or gradle-wrapper

Run/Debug main class

restclients.RestClientsApp

Build without tests

gradle build -x test

Run app

cd ./build/libs
java -jar rest-clients.jar

Report will be saved as rest-clients-performance.csv

Test results

The fastest clients are:

• Java 11 java.net.http.HttpClient
• AsyncHttpClient (org.asynchttpclient:async-http-client)
• Spring Reactive WebClient (org.springframework.boot:spring-boot-starter-webflux)
• Jetty (org.eclipse.jetty:jetty-client)

They all use NIO, Reactive architecture and can return response wrapped into CompletableFuture or Callback.

To achieve the best performance requests should be passed to rest client by several threads. Also, none of threads should wait for response by calling CompletableFuture::join or CompletableFuture::get.

Instead of that callback should be used to handle response like:

future.thenApply(response -> {});        
future.thenRun(() -> {});
future.thenCompose(...)