Server Request Interrupted errors after upgrading from 0.26.1 to commit a8c0f09

[Edward J. Stembler]

Description

I recently upgraded my Kemal app running on Heroku from version 0.26.1 to commit a8c0f09. Now it keeps getting H18 Server Request Interrupted errors constantly.

I believe this has something to do with web sockets. Is this version of Kemal using web sockets behind the scenes? I'm not using web sockets in my Kemal code. And this error didn't used to show up before on version 0.26.1.

Steps to Reproduce

1. In shard.yml change Kemal version from version: 0.26.1 to commit: a8c0f09b858162bd13c96663febef5527b322a32
2. Deploy to Heroku via git push heroku master
3. View Events in Metrics to see many H18 errors
4. Also, view the log to see the error

Expected behavior: [What you expect to happen]

No H18 errors.

Actual behavior: [What actually happens]

Many H18 errors.

Reproduces how often: [What percentage of the time does it reproduce?]

100%

Versions

Crystal: 0.35.1
Kemal: commit a8c0f09

Additional Information

Example metric events:

Example log entry:

2020-08-10T22:39:39.190036+00:00 heroku[router]: sock=backend at=error code=H18 desc="Server Request Interrupted" method=GET path="/somepath" host=somehost.com request_id=some-guid fwd="some.ip.address" dyno=web.1 connect=1ms service=14ms status=503 bytes= protocol=https

[Edward J. Stembler]

This was fixed with commit dfe7dca. Thanks @mamantoha!