Failing status checks pretty often

[d-sfounis]

Good afternoon from Greece,

After upgrading to mev-boost v1.9, I'm getting errors when calling registerValidator pretty often, probably due to the -check-relay flag:

INFO[2025-05-02T21:37:11.017+03:00] calling registerValidator on relays           method=registerValidator numRelays=2 regBytes=1327 timeout=3s ua=Lighthouse/v7.0.1-e42406d version=1.9
INFO[2025-05-02T21:37:11.258+03:00] http: POST /eth/v1/builder/validators 200     duration=0.240510 method=POST path=/eth/v1/builder/validators status=200 version=1.9
WARN[2025-05-02T21:37:14.019+03:00] error calling registerValidator on relay      error="Post \"https://boost-relay.flashbots.net/eth/v1/builder/validators\": context deadline exceeded (Client.Timeout exceeded while awaiting headers)" method=registerValidator ua=Lighthouse/v7.0.1-e42406d url="https://boost-relay.flashbots.net/eth/v1/builder/validators" version=1.9

If I'm reading this correctly, registerValidator is returning 200 so at least it's... succeeding? Partly? Sorry, I'm a bit of a noob. I'm using 2 relays:

-relay 
https://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@boost-relay.flashbots.net 
-relay 
https://0xa1559ace749633b997cb3fdacffb890aeebdb0f5a3b6aaa7eeeaf1a38af0a8fe88b9e4b1f61f236d2e64d95733327a62@relay.ultrasound.money

I don't think this was happening before the upgrade. Sometimes registerValidator will POST without issue but 80% of the time, it returns this error.

By the way, when I send a GET request to the builder asking for /eth/v1/builder/status, I just get a 200 everytime, which according to the API spec, is supposed to indicate A-OK?

[jtraglia]

Hey @d-sfounis thanks for sharing! It's not due to the -check-relay flag. This is a relay issue that we're aware of. Either the relay is a bit under-resourced or it's taking more resources to parse SSZ registrations than anticipated. But yes, this call is succeeding as it works for at least one relay. I wouldn't worry too much about this right now. We'll deal with it on our end 😄

[d-sfounis]

Alright, thanks for the calming words~

I'll close this issue tomorrow morning, if that's okay with you.

[jtraglia]

Yup, that's fine! We're working on it now.

• https://github.com/flashbots/mev-boost-relay/pull/720

[jtraglia]

Well actually, I would recommend leaving it open for better visibility. I can close it after confirming the issue is fixed.