Remote read requests fail with "snappy: corrupt input" error

[juliusv]

I tried using remote read from Prometheus against Cortex with the latest RC and noticed that these requests fail with this error message on the Cortex side:

msg="failed to parse proto" err="snappy: corrupt input"

I used git bisect to trace this down to commit 0bcbced.

The Prometheus version is 2.43 (everything on Linux/amd) and its config is simply:

global:
  scrape_interval: 5s

# Write data to Cortex.
remote_write:
  - url: "http://localhost:9009/api/prom/push"
# Read data from Cortex.
remote_read:
  - url: "http://localhost:9009/api/prom/api/v1/read"

# Let Prometheus scrape itself.
scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets:
        - 'localhost:9090'

[yeya24]

Thanks for the report! This might be a valid bug as I didn't test remote read during that test so something might break.