Async HTTP Cients - Warm Up

[jonathannaguin]

Hello,

I am running a Spring Webflux application that makes use of the Async SDK 2 clients, in particular, DynamoDB and SQS.

When running load tests against this application, I noticed some weird behaviour:

• When performing the load test, the application fails after a few seconds with "SdkClientException: Unable to execute HTTP request: Acquire operation took longer than the configured maximum time".
• The load test is injecting 50 requests per second.
• When I see that error, I stop the script, not point at carrying on after those exception.
• Now, if I simply re-run the load test script with the already running application, the container does not fail with SdkClientException. It's able to manage the load without errors.

It appears something gets warmed up on the first load which makes it smooth for the second load.

I haven't found anything on the documentation that would explain this behaviour, any help would be appreciated.

Thanks

[jonathannaguin]

For comparison purposes, I tried with AwsCrtAsyncHttpClient and I get a different exception when running the load test script:

socket operation timed out

It runs a bit longer than the Netty version, however same behaviour: if I re-run the load test, the application is able to cope with the load without exceptions.

[jonathannaguin]

This is the configuration I used for AwsCrtAsyncHttpClient:

AwsCrtAsyncHttpClient.builder()
                   .maxConcurrency(100)
                   .connectionTimeout(Duration.ofMillis(500))
                   .connectionMaxIdleTime(Duration.ofSeconds(300))
                   .tcpKeepAliveConfiguration(TcpKeepAliveConfiguration.builder()
                                                                       .keepAliveInterval(Duration.ofSeconds(75))
                                                                       .keepAliveTimeout(Duration.ofSeconds(7200))
                                                                       .build())

And for Netty:

NettyNioAsyncHttpClient.builder()
                       .sslProvider(sslProvider)
                       .maxConcurrency(100)
                       .connectionTimeout(Duration.ofMillis(500))
                       .connectionMaxIdleTime(Duration.ofSeconds(300))
                       .tcpKeepAlive(true)
                       .putChannelOption(ChannelOption.TCP_NODELAY, true)