Async Controller sending HTTP/2 (over TLS) request sequentially

[man-007]

Hi team,

In test plan, I am using multiple samplers inside async controller, and it seems the request has not been sent in asynchronous manner within a connection.

Below is my test plan,

Jmeter configurations as below(jmeter.properties/user.properties changes),

proxy.redirect.disabling=false
httpJettyClient.maxBufferSize=22214621
httpJettyClient.byteBufferPoolFactor=8
HTTPSampler.response_timeout=240000
httpJettyClient.idleTimeout=600000

HTTP2Sampler.sync_request=false
HTTPSampler.concurrentDwn=true
HTTPSampler.concurrentPool=200
HTTP2Sampler.http1_upgrade=false
HTTPSampler.use_keepalive=true

httpJettyClient.minThreads=1
httpJettyClient.maxThreads=1000
httpJettyClient.maxRequestsQueuedPerDestination=1024
httpJettyClient.maxRequestsPerConnection=1000
httpJettyClient.maxConcurrentPushedStreams=1000
httpJettyClient.maxConnectionsPerDestination=4

And using appropriate system.properties changes for TLS.

I also tried to tweak above configuration, but it is not helping.
Attaching jmeter debug logs with issue, please have a look.

Is the above configuration are affecting asynchronous behaviour of Async Controller ?

jmeter_debug.log

[man-007]

HI @3dgiordano,
Any inputs on this issue ?

[3dgiordano]

Hi @man-007

Can you send more information on how to reproduce this?

You'd need to view the ALPN and TLS/SSL negotiation debug to see if there's a problem with the server or JMeter configuration.
If the TLS negotiation isn't done correctly, it falls back to http1.1, and thus, even though it runs in parallel, it doesn't run with http2 and multiplexing.

I noticed in the logs that http protocol is used, not the secure https. This caught my attention, since to be a true "current" http2 (h2) server, it requires https, TLS, and ALPN enabled.

There are various tools and articles on the internet that can help you diagnose whether your server is correctly configured for http2, TLS/SSL, and ALPN.

For what happens behind the scenes in Java with TLS/SSL/ALPN, I recommend you raise the debug level to DEBUG and activate the Java networking debug level to be able to see the details behind the TLS/SSL and ALPN negotiation.