The latest release of Varnish Cache (6.1.0) is now available on Section, bringing about several new features and stability improvements, albeit minor in the words of Poul-Henning Kamp.
Section made this version of Varnish Cache available within our platform 2hrs after the source code release, further highlighting the speed and flexibility of the Section Edge Platform.
Update: 6.1.1
Since this article was published, there has been a new bug fix release, Varnish 6.1.1, introduced on October 26, 2018. This release is recommended for anyone running 6.1.0. Packages are available from the official repositories. There are no new features in this release, and no reconfiguration is necessary.
Notable Varnish Cache 6.1.0 Updates
- Since new users often forget to vcl.discard their old VCLs, they have added a warning when you have more than 100 VCLs loaded. There are parameters to set the threshold and decide what happens when it is exceeded (ignore/warn/error).
req.http.Host
is now mandatory and requests are handled without it on the fast DoS avoidance path.req.grace
had been previously removed, but has been reintroduced, since there are use cases that cannot be solved without it. Similarly,req.ttl
used to be deprecated and is now fully supported again.- The evaluation of the
beresp.keep
timer has changed a bit. keep sets a lifetime in the cache in addition to TTL for objects that can be validated by a 304 “Not Modified” response from the backend to a conditional request (with If-None-Match or If-Modified-Since). If an expired object is also out of grace time, thenvcl_hit
will no longer be called, so it is impossible to deliver the “keep” object in this case. - The
beresp.filters
variable is readable and writable invcl_backend_response
. This is a space-separated list of modules called VFPs, for “Varnish fetch processors”, that may be applied to a backend response body as it is being fetched. obj.hits
has been fixed to return the correct value invcl_hit
(it had been 0 invcl_hit
).- The
Host
header in client requests is mandatory for HTTP/1.1, as proscribed by the HTTP standard. If it is missing, thenbuiltin.vcl
causes a synthetic 400 “Bad request” response to be returned.
View a complete list of changes and detailed upgrade documentation.
Next Scheduled Varnish Cache Release
According to Poul-Henning, the next Varnish Cache release will take place March 15th 2019, and later this year they will decide whether that version will become 6.2 or 7.0.
If you need assistance upgrading to Varnish Cache 6.1 in your Section account, we’re here to help. Get in touch