Re: Random “http first read error: EOF” errors

[Mattias Geniar]

> Backend is Apache.

In older Varnish versions, you could sometimes see a similar error;

>   11 FetchError   c straight insufficient bytes

The error message you’re seeing might be related, as it mentions the EOF.

This happens when the backend sends a Content-Length header that doesn’t match the _actual_ content length it’s sending. In Apache, this was commonly caused by a mod_deflate misconfiguration.

For testing, could you try disabling Gzip either in your backend or strip the Accept-Encoding header in Varnish to force a plain text response?

Mattias