1. TAKE YOUR HT TP CACHING
TO THE NEX T LEVEL
With Varnish xkey or Fastly, incl Live Demo
André Rømcke (@andrerom)
VP Technical Services & Support at eZ Systems (@ezsystems)
Sep. 28th 2018 - London - #SymfonyLive
https://joind.in/talk/18336

2. So what is this talk about?
๏Some background on eZ fits into this
๏Http Cache & Cache tagging theory
๏What xkey & Fastly are
๏Practice with adding caching to symfony-demo

3. Who?
๏André Rømcke | @andrerom
๏Contributed to Symfony, FOS, Composer, PHP-FIG, Docker, & attempts for PHP
๏Works for …
๏eZ Systems AS | ez.no
๏Global 70+ people across 7+ countries, with partners & community in many many more
๏Maker of …
๏eZ Platform | ezplatform.com
๏Open Source CMS, a feature rich, flexible Full & Headless CMS, on Symfony since 2012
๏Also exists in commercial flavors: eZ Platform Enterprise & eZ Commerce (b2b e-shop)
๏Uses …

4. HttpCache in eZ Platform
๏Abstracts and uses FOSHttpCache[Bundle]
๏Lets you vary cache by user context (rights)
๏To be able to cache responses for logged in users
➡ Contributed to FOSHttpCache in 2014
๏Lets you tag the response with multiple tags
๏Out of the box with Symfony Proxy, Varnish (xkey)
& Fastly (in Enterprise version)
➡Xkey support contributed to FOSHttpCache in 2018

5. Pinch of theory:
Where Cache Tagging fits

6. Problem?

7. Problem?
๏A Entity can be rendered on several different pages (url ~= “cache key”)
๏Including as embeds, inline or via ESI fragments
๏Each page/fragment has variants based on user rights, accept headers, browser, …
๏An Entity might be represented on one variant but not on others
We need is a relationship between:
- Cache
- Code affecting it

8. Relationship: Tags
๏Example
๏url: Home/Articles/PHPBenelux tags: item-66
๏url: Home/Articles tags: item-23, item-66, (..)
๏url: api/item/66 tags: item-66
๏url: api/item/66?include=parent.name tags: item-66, item-23

9. What is:
xkey

10. ๏A VMOD for Varnish
๏Formally: Surrogate keys, Hash Ninja, Secondary Hash/Hash-Two
๏Dedicated secondary index in memory for objects
๏Allows for expiring objects with softpurge() for use with Grace
๏Part of official `varnish-modules` VMOD collection package
๏Out of the box as of FOSHttpCacheBundle v2.4
๏Cache Tagging support with Symfony Proxy also landed in that release
xkey: Surrogate keys for Varnish

11. A bit about:
Fastly

12. ๏World wide CDN
๏Originally based on Varnish 2.x
๏So familiar VCL to configure it in many ways
๏Soft purging, grace handling, ….
๏Surrogate keys support builtin in
๏One big difference from Varnish:
๏Purge/Refresh of cache is done via API
Rather easy to add “ProxyClient” for FOSHttpCacheBundle
๏Especially as of 2.4, might get built-in support in future version
Fastly CDN

13. Let’s change Symfon Demo to:
Look at Varnish (incl. xkey) and the VCL
Enable caching, & cache tagging
Debug & look into common Symfony issues
Now on Github:
https://github.com/andrerom/sf-london-2018-httpcache-demo

14. The End, Questions?
Talk + Slides: https://joind.in/talk/18336
Code: https://github.com/andrerom/sf-london-2018-httpcache-demo
Other talks: http://www.slideshare.net/andreromcke
Twitter: @andrerom
FOSHttpCache: http://foshttpcache.readthedocs.io/en/latest/
Varnish xkey: https://github.com/varnish/varnish-modules/
TL;DR: Use FOSHttpCache,
and/or use eZ Platform which does all this for you 😉