How to set a timeout in Spring 5 WebFlux WebClient

Question

I'm trying to set timeout on my WebClient, here is the current code :

SslContext sslContext = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();

ClientHttpConnector httpConnector = new ReactorClientHttpConnector(opt -> {
    opt.sslContext(sslContext);
    HttpClientOptions option = HttpClientOptions.builder().build();
    opt.from(option);
});
return WebClient.builder().clientConnector(httpConnector).defaultHeader("Authorization", xxxx)
                .baseUrl(this.opusConfig.getBaseURL()).build();

I need to add timeout and also pooling strategy, I was thinking of something like that :

PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
cm.setMaxTotal(this.applicationConfig.getHttpClientMaxPoolSize());
cm.setDefaultMaxPerRoute(this.applicationConfig.getHttpClientMaxPoolSize());
cm.closeIdleConnections(this.applicationConfig.getServerIdleTimeout(), TimeUnit.MILLISECONDS);

RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(this.applicationConfig.getHttpClientSocketTimeout())
        .setConnectTimeout(this.applicationConfig.getHttpClientConnectTimeout())
        .setConnectionRequestTimeout(this.applicationConfig.getHttpClientRequestTimeout()).build();

CloseableHttpClient httpClient = HttpClients.custom().setDefaultRequestConfig(requestConfig).setConnectionManager(cm).build();

But I can't figure out how to set the httpClient in my webclient

user_5834477 · Answer

To set the read and connect timeout I use the method below, because the SO_TIMEOUT option is not available for channels using NIO (and giving the warning Unknown channel option 'SO_TIMEOUT' for channel '[id: 0xa716fcb2]')

ReactorClientHttpConnector connector = new ReactorClientHttpConnector(
          options -> options.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 2000)
                            .compression(true)
                            .afterNettyContextInit(ctx -> {
                                ctx.addHandlerLast(new ReadTimeoutHandler(5000, TimeUnit.MILLISECONDS));
                            }));
return WebClient.builder()
                .clientConnector(connector)
                .build();

user_3665698 · Answer

ReactorClientHttpConnector API changed in version Spring WebFlux 5.1.

So I do the following (Kotlin syntax, based on @joshiste example):

val tcpClient = TcpClient.create()
    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000)
    .doOnConnected { connection ->
        connection.addHandlerLast(ReadTimeoutHandler(10))
            .addHandlerLast(WriteTimeoutHandler(10))
    }

val myWebClient = webClientBuilder
    .clientConnector(ReactorClientHttpConnector(HttpClient.from(tcpClient)))
    .baseUrl(myEndPoint)
    .build()

UPDATE 2021

HttpClient.from in deprecated in last version of Reactive Netty. It was copying the configuration of the tcpClient. Now we can configure httpClient directly.

val httpClient = HttpClient.create()
    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10_000)
    .doOnConnected { connection ->
        connection.addHandlerLast(ReadTimeoutHandler(10))
            .addHandlerLast(WriteTimeoutHandler(10))
    }

val myWebClient = webClientBuilder
    .clientConnector(ReactorClientHttpConnector(httpClient))
    .baseUrl(myEndPoint)
    .build()

user_2852528 · Answer

As Spring Webflux was updated, here is a solution that works for Java (based on the answer for Kotlin):

TcpClient timeoutClient = TcpClient.create()
    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, SECONDS*1000)
    .doOnConnected(
        c -> c.addHandlerLast(new ReadTimeoutHandler(SECONDS))
              .addHandlerLast(new WriteTimeoutHandler(SECONDS)));
return webClientBuilder.baseUrl(YOUR_URL)
       .clientConnector(new ReactorClientHttpConnector(HttpClient.from(timeoutClient)))
       .build();

UPDATE 2021

since HttpClient.from(TcpClient) is deprectaed now it's even easier:

return WebClient.builder()
                .baseUrl(YOUR_URL)
                .clientConnector(new ReactorClientHttpConnector(HttpClient.create()
                                                                          .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, SECONDS * 1000)
                                                                          .doOnConnected(c -> c.addHandlerLast(new ReadTimeoutHandler(SECONDS))
                                                                                               .addHandlerLast(new WriteTimeoutHandler(SECONDS)))))
                .build();

user_11868214 · Answer

With Spring Webflux 5.1.8 I ran into problems yielding the error messages below using the answer from mcoolive when executing multiple subsequent tests that uses the WebClient.

Force-closing a channel whose registration task was not accepted by an event loop
Failed to submit a listener notification task. Event loop shut down?

Adding a connection provider and loop resources solved my problem:

final ConnectionProvider theTcpClientPool = ConnectionProvider.elastic("tcp-client-pool");
final LoopResources theTcpClientLoopResources = LoopResources.create("tcp-client-loop");

final TcpClient theTcpClient = TcpClient
    .create(theTcpClientPool)
    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000)
    .runOn(theTcpClientLoopResources)
    .doOnConnected(theConnection -> {
        theConnection.addHandlerLast(new ReadTimeoutHandler(mTimeoutInMillisec, TimeUnit.MILLISECONDS));
        theConnection.addHandlerLast(new WriteTimeoutHandler(mTimeoutInMillisec, TimeUnit.MILLISECONDS));
    });

WebClient theWebClient = WebClient.builder()
    .baseUrl(mVfwsServerBaseUrl)
    .clientConnector(new ReactorClientHttpConnector(HttpClient.from(theTcpClient)))
    .build();

user_5058989 · Answer

Rather than creating your own WebClient.Builder, you can provide a custom ReactorNettyHttpClientMapper which is going to be applied to the default WebClient.Builder:

@Configuration
class MyAppConfiguration {

    @Bean
    fun reactorNettyHttpClientMapper(): ReactorNettyHttpClientMapper {
        return ReactorNettyHttpClientMapper { httpClient ->
            httpClient.tcpConfiguration { tcpClient ->
                tcpClient.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 30_000)
                    .doOnConnected { connection ->
                        connection.addHandlerLast(ReadTimeoutHandler(60))
                            .addHandlerLast(WriteTimeoutHandler(60))
                    }
            }
        }
    }
}

user_1092172 · Answer

You can use overloaded block() method which accepts a timeout on Mono object. Or there is a timeout() method directly available on Mono object.

WebClient webClient = WebClient.builder()
              .baseUrl( "https://test.com" )
              .defaultHeader( HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE )
              .build(); 

webClient.post()
              .uri( "/services/some/uri" )
              .body( Mono.just( YourEntityClassObject ), YourEntityClass.class )
              .retrieve()
              .bodyToMono( String.class )
              .timeout(Duration.ofMillis( 5000 )) // option 1
              .block(Duration.ofMillis( 5000 )); // option 2

user_8494907 · Answer

Based on the above comment if you want to add a Socket Timeout just add it as another option in the same timeoutClient.

TcpClient timeoutClient = TcpClient.create()
    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, SECONDS*10) //Connect Timeout
    .option(ChannelOption.SO_TIMEOUT,1000) // Socket Timeout
    .doOnConnected(
        c -> c.addHandlerLast(new ReadTimeoutHandler(SECONDS))
              .addHandlerLast(new WriteTimeoutHandler(SECONDS)));
return webClientBuilder.baseUrl(YOUR_URL)
       .clientConnector(new ReactorClientHttpConnector(HttpClient.from(timeoutClient)))
       .build();

user_8098669 · Answer

Kotlin Syntax!!

webClient
.post()
.body(BodyInserters.fromObject(body))
.headers(headersSetter)
.retrieve()
.bodyToMono()
.timeout(Duration.ofSeconds(30)) /// specify timeout duration
.doOnNext {
    logger.info{ "log something"}
}
.onErrorMap { throwable ->
    logger.error{"do some transformation"}
    throwable
}

How to set a timeout in Spring 5 WebFlux WebClient

10 Answers