Varnish gets 'ESI' clever on content for a faster web

No more quirky headlines trying to crowbar in references to ‘polish’, ‘shine’ or any form of gleaming surface we promise, caching and content delivery specialist Varnish Software has announced Varnish Plus with parallel ESI and Edgestash.

What is ESI?

Edge Side Includes (or ESI) is a language to include fragments of web pages in other web pages. Think of it as HTML include statement that works over HTTP. On most web sites a lot of content is shared between pages. Regenerating this content for every page view is wasteful and ESI tries to address that letting you decide the cache policy for each fragment individually.

Edgestash works at a similar level, but is focused on mobile content delivery. Edgestash is a pure templating language that does the actual page assembly at the network edge, speeding up delivery for mobile web pages. You can read more here.

These new features aim to improve content delivery on mobile and provide that thing that vendors in this space like to call enhanced user experience and content engagement.

The new release of Varnish Plus also includes scalable TCP acceleration to speed up application and content delivery by what is claimed to be up to 40 percent.

Web developers need delivery deliverance

The firm asserts that as the percentage of consumers accessing the web via mobile devices continues to climb, increasing the speed of mobile content delivery is a bigger priority than ever before.

More on Parallel ESI — Addressing the challenges of web infrastructure scaling, this feature enables a web page to immediately seek out and fetch needed fragments all at the same time which kills latency and provides responsiveness for ESI-heavy pages.

Looking at Edgestash again, this feature allows for content rendering ‘on the wire’ by moving the page assemble logic from the browser to the edge (server side). Client-side logic and page assembly can still exist, but when complemented with this kind of edge-side rendering, it becomes much more manageable and high performance, especially on mobile.

“The new version of Varnish Plus is also ideal for dynamic content transmission across a wide range of web applications and streaming content accessed by a broad set of users and devices,” said the firm, in a press statement.

We are living in a new digital era — and this this evolution introduces new challenges to your content delivery architecture says Lars Larsson CEO, Varnish Software.

These two new features will be gradually rolled out during the coming weeks.