Beyla not sending headers on Java (Spring Boot) but will send them through Go (HTTP1.1 calls)

[ddz99]

I have an issue/question. Supposedly Beyla should be capable to rewrite headers to send the trace parent even in Java applications, right?
I made a demo to showcase to my company so that we could use Beyla but I cant seem to figure out why it doesnt work.
Go apps do send the traceparent in the request headers, but Spring apps do not. Is there a reason for this?

Java Spring is working on HTTP1.1

Kernel is 5.15 on WSL2 Ubuntu but I've tried this on 4.18 RHEL8 aswell.

Running Beyla 1.90 built from Main branch on this repo.

[grcevski]

Hi @ddz99 , we are still working on this and it will happen soon. Two things we need to finish:

1. The context propagation support. If you'd like you can try this today on the main branch if you set this option BEYLA_BPF_TC_L7_CP=true. It's not documented because we are still working on it. If you have Beyla on both sides of the communication you can also try BEYLA_BPF_TC_CP=true, but don't use both of these options together. The current form of BEYLA_BPF_TC_L7_CP needs kernel 5.17 (which seems newer than what you have), I expect that in 2 weeks this requirement will not be there anymore.
2. We have issues with certain Java thread pools, so depending on how you use the Spring rest client it may not work. We have plan to fix this in the next month or so.

Please give this a shot and let me know if it works.

[grcevski]

You can see that we've started building tests with this new feature.

K8s examples: https://github.com/grafana/beyla/blob/main/test/integration/k8s/manifests/06-beyla-daemonset-multi-node.yml and https://github.com/grafana/beyla/blob/main/test/integration/k8s/manifests/06-beyla-daemonset-multi-node-l7.yml.

Here's a docker compose example that is also using Java in the mix with BEYLA_BPF_TC_L7_CP=true https://github.com/grafana/beyla/blob/main/test/integration/docker-compose-multiexec-host.yml