How do I set a timeout on Spring's AsyncRestTemplate?

Question

I've setup a RestTemplate and an AsyncRestTemplate in my project similar to the following:

http://vincentdevillers.blogspot.fr/2013/10/a-best-spring-asyncresttemplate.html

I've noticed that the connect timeout doesn't actually work unless I change the httpRequestFactory() bean to be the following:

@Bean
public ClientHttpRequestFactory httpRequestFactory() {
    HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient());
    factory.setConnectTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);
    factory.setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);
    return factory;
}

If I set DEFAULT_READ_TIMEOUT_MILLISECONDS to 5, a timeout occurs when I use restTemplate (as expected). However, when I use AsyncRestTemplate, a timeout doesn't occur. I've modified the asyncHttpRequestFactory() like httpRequestFactory(), but no dice.

@Bean
public AsyncClientHttpRequestFactory asyncHttpRequestFactory() {
    HttpComponentsAsyncClientHttpRequestFactory factory = new HttpComponentsAsyncClientHttpRequestFactory(asyncHttpClient());
    factory.setConnectTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);
    factory.setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);
    return factory;
}

Here's how I'm attempting to use AsyncRestTemplate in a Spring MVC Controller:

String url = "...";
// Start the clock
long start = System.currentTimeMillis();

ListenableFuture<ResponseEntity<String>> results = asyncRestTemplate.getForEntity(url, String.class);
// Wait until the request is finished
while (!(results.isDone())) {
    Thread.sleep(10); //millisecond pause between each check
}
System.out.println("Elapsed time: " + (System.currentTimeMillis() - start));
return results.get().getBody();

How can I get AsyncRestTemplate to read my connection timeout settings?

On a related note, https://spring.io/guides/gs/async-method/ uses @Async and RestTemplate and seems to accomplish what I'm looking for. What's the advantage of using AsyncRestTemplate over RestTemplate?

Looking at the source the `HttpComponentsAsyncClientHttpRequestFactory` ignores the `connectTimeout` and `readTimeout` properties. I'm not sure why. — M. Deinum, Feb 23 '14 at 19:37
Hi. Sorry for the time, but can someone solve the problem? I have the same doubt like this: https://stackoverflow.com/questions/50594022/how-to-increase-timeout-asyncresttemplate-class — J. Abel, May 30 '18 at 13:58

oskansavli · Answer 1 · 2016-05-27T22:09:31.290

Very similar to the sync one:

final SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
requestFactory.setTaskExecutor(new SimpleAsyncTaskExecutor());
requestFactory.setConnectTimeout(connectTimeout);
requestFactory.setReadTimeout(readTimeout);

final AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate();
asyncRestTemplate.setAsyncRequestFactory(requestFactory);

From the source code, you can see that AsyncRestTemplate instance is created by using a SimpleClientHttpRequestFactory together with a SimpleAsyncTaskExecutor. So you can just do the same using a SimpleClientHttpRequestFactory instance whose timeout values are set.

Could use some edits to better explain how this answers the question. — paisanco, May 27 '16 at 16:57

score 4 · Answer 2 · answered Mar 27 '14 at 02:32

The AsyncRestTemplate relies on HTTP client's NIO capabilities so you can manage a large number of connections with a small number of threads. To achieve the same with @Async + RestTemplate would require much more resources. If you're only doing it in a few places then it's probably okay although even then AsyncRestTemplate, since it exists, is a little nicer and more specialized for the use case.

As for the read timeout it looks like it might be an oversight. Feel free to create a ticket. A quick look at this page, the "HttpAsyncClient configuration" example, shows using:

IOReactorConfig.custom().setConnectTimeout(30000).

I suppose you could give that a quick try

I also have similar question [here](http://stackoverflow.com/questions/29380653/how-to-properly-cancel-the-http-request-if-they-are-taking-too-much-time) which uses `AsyncRestTemplate` along with its `ListenableFuture` and I have few doubts on my problem which I am trying to accomplish. If possible, can you help me out over there. I am finding `AsyncRestTemplate` pretty cool since it uses NIO based connections. — john, Apr 01 '15 at 18:49

score 3 · Answer 3 · answered Mar 26 '14 at 17:41

3

I think the point of AsyncRestTemplate is the ListenableFuture (whose features you are not really using). So probably @Async is fine for your use case. Also, I think that results.get(5,TimeUnit.SECOND) is more efficient (and elegant) then looping with a Thread.sleep(...), but that's up to you I guess. Or maybe I'm missing something.

answered Mar 26 '14 at 17:41

Dave Syer

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I also have similar question [here](http://stackoverflow.com/questions/29380653/how-to-properly-cancel-the-http-request-if-they-are-taking-too-much-time) which uses `AsyncRestTemplate` along with its `ListenableFuture` and I have few doubts on my problem which I am trying to accomplish. If possible, can you help me out over there whenever you get a chance. Any help is really appreciated. – john Apr 04 '15 at 09:06
I think it's a typo there. It should be `results.get(5,TimeUnit.SECONDS)` instead of `results.get(5,TimeUnit.SECOND)` – simomo Dec 04 '17 at 02:58

score 0 · Answer 4 · answered Jan 19 '16 at 10:33

public CloseableHttpAsyncClient asyncHttpClient() {
    IOReactorConfig ioReactorConfig = IOReactorConfig.custom().setConnectTimeout(getProperties().getConnectTimeout()).setSoTimeout(getProperties().getReadTimeout()).build()
    return  HttpAsyncClients.custom().setDefaultIOReactorConfig(ioReactorConfig).build();
}

like this, the AsyncRestTemplate timeout configurate is ok.

How do I set a timeout on Spring's AsyncRestTemplate?

4 Answers4