Metrics server not responding with HTTP 1.1

[cirvladimir]

I'm using the default way of starting the server with start_http_server(). I noticed that the server responds with HTTP/1.0 to HTTP/1.1 requests. Is there a flag I need to set to support HTTP/1.1?

[jvperrin]

In case anyone else comes across this and wants to change the version, it's coming from wsgiref.handlers in the python stdlib: https://github.com/python/cpython/blob/3.11/Lib/wsgiref/handlers.py#L104

You can change to using 1.1 by doing this:

from wsgiref.simple_server import ServerHandler

ServerHandler.http_version = "1.1"

Then later on when you call start_http_server(8000) (or similar) it will use this HTTP version and respond with HTTP/1.1 200 OK in responses.

[llamafilm]

@jvperrin great find, thank you! This one change makes a huge difference in performance. With my simple test exporter that just exposes 1 metric, scraping from Grafana Alloy, the CPU utilization and network traffic of the Alloy container are both reduced by about 55%. If the exporter returns a large number of metrics then the difference would be less noticeable.