`h2c` services aren't scaling to zero
Open
Nobody has claimed this yet.
area/autoscale
kind/bug
lifecycle/frozen
triage/accepted
- Dominant language
- Go
- Stars
- 6.1k
- Forks
- 1.2k
- Avg merge
- 2d 7h
- Merged PRs (30d)
- 2
Description
/area autoscale
What version of Knative?
1.4
Expected Behavior
Unroutable revisions scale to zero (even with minScale).
Actual Behavior
I see pods for most of our revisions.
Steps to Reproduce the Problem
Not entirely clear how we got into this state, since it just started happening.
I see the following in the autoscaler logs, which would indicate that maybe this is an http/1 vs. http/2 thing 🤔
Probing activator = false, err = unexpected body: want \"activator\", got \"net/http: HTTP/1.x transport connection broken: malformed HTTP response \\\"\\\\x00\\\\x00\\\\x06\\\\x04\\\\x00\\\\x00\\\\x00\\\\x00\\\\x00\\\\x00\\\\x05\\\\x00\\\\x00@\\\\x00\\\"\\n\"
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Begin with the autoscaler logs and the h2c probing failure described in the issue, comparing the expected activator response with the malformed HTTP/1.x response. Reproduce the scale-to-zero case for an unroutable revision and verify that h2c services no longer leave pods running; no source files or tests are identified here.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- go, kubernetes
- Domain
- backend, infrastructure
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100