Is it wise to create Webclient again and again in Webflux since my base URI is not fixed?

Question

In my microservice I have to fetch data from places. Some of the URL's are fixed but some are not . So do I need to create Webclient again and again if my base URL changes. If not then is the below way correct to create Web Client. WebClient.create(); and later changing the URI again and again whenever I make a call. As per my understanding creating a WebClient must be some heavy operation.

ReactorClientHttpConnector connector = new ReactorClientHttpConnector(
                options -> options.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, requestTimeout).compression(true)
                        .afterNettyContextInit(ctx ->  ctx.addHandlerLast(new ReadTimeoutHandler(readTimeout, TimeUnit.MILLISECONDS))));
        return WebClient.builder()
                        .clientConnector(connector)
                        .baseUrl(hostURL)
                        .build();

Answer 1

WebClient instances are meant to be reusable. The only reason you'd need to have different client instances is for specific needs: instrumentation for observability, specific authentication client filters, specific connection/read/write timeouts.

Different base URIs is not a strong reason to create different instances. It's perfectly fine to create an instance and not set a base URI, it's merely a convenience to avoid duplication when calling the same host over and over again.

This is perfectly fine:

WebClient webClient = WebClient.builder().build();

Mono<Resource> resource = webClient.get().uri("http://example.org/resource").retrieve()...;
Mono<Project> project = webClient.get().uri("http://spring.io/projects/spring-boot").retrieve()...;

Note that if you use Spring Boot, you should instead consider building your webclient instance using the provided WebClient.Builder (see the Spring Boot reference documentation).