Free and Open Source Meetup with Tech Evangelist Thijs Feryn (Varnish)

​We are pleased to organize the last Open Source meetup to wrap up the year, in partnership with Varnish and Antler. A huge shoutout to Varnish and Antler for sponsoring us with this awesome venue. As an added bonus, we are delighted to have Grafana join us with a special presentation on SLO.

​Let's welcome back Thijs Feryn from Varnish. A global authority on web architecture, Thijs has shared his expertise through dynamic presentations in 22 countries, reaching audiences at over 340 events. His deep understanding of web performance, scalability, and content delivery is matched by his passionate contributions to open-source projects.

​1. Welcome by Organizers and Venue Host

​2. Presentation by Thijs Feryn from Varnish
Synopsis: We use caching proxies like Varnish to accelerate our web content and to make our platforms more scalable.

​However, ensuring the right content is removed from the cache at the right time is equally important. Some may argue that the impact of caching too long is way bigger than not caching long enough.

​Imagine a new website that cannot show a breaking news story on its website, because the cache still contains the old version.

​In this presentation, we’ll take a closer look at how cache invalidation, cache revalidation and cache purging works.

​Here are some of the main topics we’ll cover:
- How to identify and categorize content in the cache
- How to identify outdated content
- How to remove one or more objects from the cache
- How to control the blast radius of cache purges
- How to mitigate the performance impact of purged objects from the cache
- The difference between purging, invalidation & revalidation
- How to implement a cache invalidation strategy in your application
- How to secure access to your cache invalidation endpoint

​3. Presentation by Joe Blubaugh from Grafana
Don’t Get Out of Bed for Anything less than an SLO
Service level objectives are a powerful monitoring and alerting philosophy that can reduce stress for on-call engineers and keep teams focused on delivering value to customers.
We’ll cover:

• ​The concept of “service level”

• ​Measuring service levels effectively

• ​“Error budget” and realistic objectives

• ​Multi-window, multi-burn rate alerting rules.

• ​OSS tools that can help you get started with SLOs

​4. Networking

​We look forward to seeing you all and we welcome all to join us at this event.