The content delivery network Fastly provides caching for websites with an extremely high granularity, advertising a purge time of 150 milliseconds.
With the increasingly crowded market for content delivery networks (CDNs), finding a CDN that suits your organization's unique needs can be a challenge. Depending on the service being provided, the benefits of various providers can make a world of difference in your website's performance.
Fastly — a CDN founded by Artur Bergman, the former CTO of Wikia — is taking an interesting direction in providing caching for websites with an extremely high granularity, advertising a purge time of 150 milliseconds.
Starting from a different perspective
Fastly operates from a rewrite of Varnish, an accelerator designed to handle only HTTP caching for dynamic websites. For comparison, the competing firm CloudFlare operates from a modified version of nginx, which was designed as a more general-purpose reverse proxy for HTTP(S), as well as the SMTP, POP3, and IMAP protocols.
Varnish — and by extension, Fastly — is able to load and execute new code without a restart. The configuration is written in Varnish Control Language (VCL). The key difference of Fastly is the real-time performance viewer (see a demo of the viewer).
Using Fastly with streaming
Nothing is quite as bandwidth-intensive as streaming video, and live streaming video adds further complications to the mix. Ensuring a more direct transit for video is of the utmost importance when broadcasting, especially for live events.
As Fastly supports anything HTTP-based, it is possible to use HTTP Live Streaming, Adobe Dynamic Streaming, Microsoft Smooth Streaming, and MPEG-DASH for video streaming. Audio streaming, such as through the HTTP-based Nullsoft SHOUTcast, is also possible.
Looking to two Fastly use cases
The Guardian's recent complete website redesign utilizes Fastly, in part to keep bleeding-edge breaking news on its homepage.
Imgur, the image-hosting website launched in 2009, uses Fastly to deliver the images uploaded to its service. Alexa ranks Imgur as the 47th most viewed site globally, an impressive feat for a site that only hosts images. An important role played here by Fastly is the international caching for users around the globe, as pictures of irritated-looking cats and celebrities are of worldwide appeal.
Planning for expansion
Fastly has nine points of presence (POP) in the US: San Jose, Los Angeles, Seattle, Dallas, Chicago, Atlanta, Miami, Ashburn, and New York; four in Europe: Amsterdam, Frankfurt, and two POPs in London; three in Asia: Hong Kong, Singapore, and Tokyo; and three in Australia and New Zealand: Auckland, Wellington, and Sydney.
The planned expansions are for Denver in the US, Stockholm in Europe, Osaka, Taiwan, and a POP in an as-of-yet unannounced city in South Korea. Plans also exist to bring Fastly to Brazil and to South Africa.
Curiously, there are no POPs or plans for expansion into Canada. Tom Daly, the Vice President of Infrastructure, notes that the organization is always evaluating potential new locations, and that "For Canada, the major metropolitan areas including Toronto, Montreal, and Vancouver are well served from POPs in Seattle, Chicago, and New York with reasonable latency and connect times. Again, as traffic grows, we will consider investments into additional POPs as needed."
What's your position?
What is the decision making process for contracting a CDN provider for your organization? What vendor do you use? Let us know in the comments.