Make calls to endpoint discovery non-blocking for asynchornous clients

[anirudh9391]

Make endpoint discovery calls fully asynchronous.

Motivation and Context

Conforms to the expectation that asynchronous requests made by non-blocking clients do not block the thread.

Modifications

Created a new internal API to be invoked by asynchronous clients. This new API returns a completableFuture as opposed to waiting on request object completion

Testing

• Existing Unit tests for Endpoint Discovery pass
• Codegen tests pass

E2E test validation

    @Test
    public void test() {
        SdkEventLoopGroup group = SdkEventLoopGroup.builder()
                                                   .numberOfThreads(1)
                                                   .build();

        SqsAsyncClient sqs = SqsAsyncClient.builder()
                                           .asyncConfiguration(o -> o.advancedOption(SdkAdvancedAsyncClientOption.FUTURE_COMPLETION_EXECUTOR, Runnable::run))
                                           .region(Region.US_WEST_2)
                                           .httpClient(NettyNioAsyncHttpClient.builder()
                                                                              .eventLoopGroup(group)
                                                                              .build())
                                           .build();

        TimestreamWriteAsyncClient timestream = TimestreamWriteAsyncClient.builder().region(Region.US_WEST_2)
                                                                          .httpClient(NettyNioAsyncHttpClient.builder()
                                                                                                             .eventLoopGroup(group).build())
                                                                          .build();

        CompletableFuture<ListQueuesResponse> future = sqs.listQueues();
        future.whenComplete((r, e) -> {
                                timestream.listDatabases(req -> req.maxResults(1));
                                assertThat(1).isEqualTo(1);
                            }
        ).join();

        assertThat(1).isEqualTo(1);
    }

Screenshots (if appropriate)

Types of changes

• [ x] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

[dagnir]

Can we include the test we discussed offline for testing a client using Runnable::run for FUTURE_COMPLETION_EXECUTOR?

[zoewangg]

Should we propagate exception cancellation? What happens if endpoint discovery takes longer than the configured client execution timeout? Would the request fail properly?

[anirudh9391]

hmm.. So the cancellation Exception is going to be thrown here

return discoverEndpoint(request).handle(
                (endpointDiscoveryEndpoint, throwable) -> {
                    if (throwable != null) {
                        throw new RuntimeException(throwable);

This will be propogated upwards, unless you mean something else

[anirudh9391]

I am wrapping it around an EndpointDiscoveryFailedException

[zoewangg]

I meant if users have client execution timeout enabled and if endpoint discovery takes longer than the configured timeout, the returned future will be cancelled, but will endpoint discovery future also be cancelled?

[zoewangg]

I think we just need CompletableFutureUtils.forwardExceptionTo(executeFuture, endpointFuture ); on line 277.

Can we write a test to verify that?

Example: https://github.com/aws/aws-sdk-java-v2/blob/master/services/s3/src/test/java/software/amazon/awssdk/services/s3/internal/crt/CopyObjectHelperTest.java#L314

[anirudh9391]

Discussed offline. Doing this as a follow up item

[zoewangg]

This needs to be ${awsjavasdk.version}

It seems odd that we are using real service clients in codegen-generated-classes-test, is there any reason we can't use EndpointDiscoveryTestAsyncClient

Missed tests

[sonarcloud]

Quality Gate passed

Issues
10 New issues
0 Accepted issues

Measures
0 Security Hotspots
86.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud