SocketTimeoutException outbound request - spring boot resttemplate

[Ronald Bergmann]

We use the java11 runtime and F1 instances, spring boot 2.2.5 and didn't experience the following issues with other apps deployed on GAE.

When trying to perform an outbound (POST) request we end up with an SocketTimeoutException:

java.util.concurrent.ExecutionException: org.springframework.web.client.ResourceAccessException: I/O error on POST request for "https://xyz.tld/": connect timed out; nested exception is java.net.SocketTimeoutException: connect timed out
    at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:na]
    at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:205) ~[na:na]
    at a.b.c.service.AddressService.get(AddressService.java:63) ~[classes!/:0-0-4]
    at a.b.c.rest.AddressRequestsController.d(AddressRequestsController.java:73) ~[classes!/:0-0-4]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]

   ...

There's nothing fancy about resttemplate:

restTemplate = new RestTemplateBuilder()
    .setConnectTimeout(Duration.ofMillis(CONNECT_TIMEOUT))
    .setReadTimeout(Duration.ofMillis(READ_TIMEOUT))
    .build();

...

restTemplate.postForEntity(searchUrl, request, String.class);

With timeouts of 5 and 8 seconds.

Runs fine locally and the other end is alive and responsive.

Any ideas what's going wrong?

[nibrass]

Hello Ronald,

In order to investigate further and determine your issue, could you please answer the following:

1) Are you using Google App Engine Standard or Flexible?

2) What are you doing in your code ( calls to other Google Cloud Platform products , etc ) ?

3) Other apps deployed in Google Cloud Platform is also using java11 runtime? 

Could you please share your app.yaml file?

Thank you.

Nibrass Haider

[Ronald Bergmann]

Hi Nibrass,

1) Standard java11

app.yaml:

# [START runtime]
runtime: java11
instance_class: F1
automatic_scaling:
  min_instances: 0
  min_idle_instances: 0
  max_instances: 2

entrypoint: java -noverify -jar app.jar

inbound_services:
  - warmup

env_variables:
  JAVA_TOOL_OPTIONS: "-XX:MaxRAM=256 -Xmx32m"
# [END runtime]

I also wonder why I suddenly need the entrypoint. I didn't have to specify one with the other app(s), I think.

2) Pretty much what's above:

// request headers
final HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
headers.set("Referer", REFERER);
headers.set("User-Agent", uaString);
headers.setAccept(Collections.singletonList(MediaType.ALL));

// values
final MultiValueMap<String, String> values = new LinkedMultiValueMap<>();
values.add("suchart", "detail");
// ... and some others

final HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(values, headers);
if (restTemplate == null)
    

restTemplate = new RestTemplateBuilder()
        .setConnectTimeout(Duration.ofMillis(CONNECT_TIMEOUT))
        .setReadTimeout(Duration.ofMillis(READ_TIMEOUT))
        .build();

return restTemplate.postForEntity(searchUrl, request, String.class);

3) Yupp. Here's the app.yaml of another app:

# [START runtime]
runtime: java11
instance_class: F2
automatic_scaling:
  min_instances: 1
  min_idle_instances: 1
  max_instances: 8

#entrypoint: java -noverify -jar -0.0.1-SNAPSHOT.jar

inbound_services:
  - warmup

env_variables:
  JAVA_TOOL_OPTIONS: "-XX:MaxRAM=512m -Xmx64m"
# [END runtime]

No entrypoint specified here. This app does not use the same resttemplate but at least org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate without issues.

Hope this helps. If you need the project ID or anything else just let me know.

[nibrass]

Hi Ronald,

The entrypoint is optional, if you are not using a custom jar, you don't need an entrypoint [1]

The SocketTimeOutException could be caused when you are trying to connect to Elastic. Are you using sockets in your request?

Where do you have Elastic?

Looking forward to your reply.

Sincerely,

Nibrass Haider

=========================

[1] https://cloud.google.com/appengine/docs/standard/java11/config/appref#entrypoint

[Ronald Bergmann]

Hey nibrass,

there's no issue with Elastic. That was just an example of another app using resttemplate. But glancing at the code it actually does not seem to be based on spring's resttemplate.

Spring utilizes HttpURLConnection.

When leaving out the entry point mvn com.google.cloud.tools:appengine-maven-plugin:2.2.0:deploy fails with:

[INFO] GCLOUD: Error ID: 80D70A67.

[INFO] GCLOUD: Error type: InternalError.
[INFO] GCLOUD: Error message: Failed to generate app command: failure to generate application start command: missing entrypoint entry in app.yaml.

[goya]

Hi, 

I have created a private issue on Issue Tracker to better investigate this issue as we will need access to your project to check the logs and use other internal tools to understand which might be the cause for these timeouts. 

You should be able to access the private issue by using the same email address you used to create this discussion. 

Further interactions will be done on: https://issuetracker.google.com/153078097 

On Monday, March 23, 2020 at 11:41:21 PM UTC+1, Ronald Bergmann wrote: