Review: Limelight Orchestrate Performance
Sometimes images are combined to be delivered as a single object, and may also be compressed using lossless or lossy techniques so that the image can be transferred at a low bitrate, and then, over the course of time, improvements to the quality can be made, once other prioritized parts of the page are loaded. This is akin to video "fast start" for still images.
Interestingly, there can be benefits to using a CDN to optimize website delivery even within a local region, when the users are close the the origin (i.e. servers are hosted in London and users are in London). While the underlying network latency may not be improved, other optimizations may provide significant improvements to the user experience and the origin can be scaled to meet spiky usage demand. This highlights that a CDN can help even with local delivery of websites.
Testing
To demonstrate things in practice, Steve tested http://cellmux.com/the-newsroom using a series of standard synthetic testing models. It was noted that it would be more typical to have the CNAME record www.cellmux.com
Miller-Jones ran global performance tests in each major continent. He compared a direct pull of the content from the origin with a pull of the website through the Limelight Orchestrate Performance product. Gomez was used as a third-party synthetic testing tool, and the measurements analysed were Time to First Byte, Time to Last Byte, and the overall content download time for the page.
He also used an instance of Google’s open source WebPageTest tool, running on Limelight’s own infrastructure, to generate a Speed Index analysis producing a “filmstrip” to show how the improvements are actually experienced by end users. He noted that cellmux.com's pages are cacheable for 3 seconds. He tested using a vanilla content acceleration configuration for dynamic content acceleration, and also tested in-lining and image compression.
Results
Did it work? Well, the overall average improvement globally was shown to be 65.7%, with massive improvements to Oceania and Australia in excess of 136%. So the short answer is yes.
The above shows the performance test on www.cellmux.com over a 24-hour period.
The blue graph points show how we are getting out (TTLB) to various regions with no Orchestrate Performance, direct from the origin server, and the other graphs break out how we reach these regions with Limelight in the mix.
Overall this shows how a CDN can really help a web publisher improve its users experiences if their websites. In LA we can see that the page is loaded and usable in 9.1 seconds with no acceleration, and with acceleration 5.4 seconds.
Now not all components and services are supported, so for example WebSockets and similar "non-port 80" services may not be included in your CDN’s proposition, and some of these services are only supported if there is significant demand.
It has been an interesting voyage for me, having spent a long time in the sector, to peek over the wall of streaming media and into that of its partner, web content delivery, and to see that while there are many common themes, there are equally many different approaches needed for these different types of media; and yet they are all equally critical to a robust and rounded end user experience.
As the cellmux.com analysis shows, in the context of Limelight’s Orchestrate Performance platform even a simple website such as www.cellmux.com can show significant performance benefits when they are deployed behind a well-organized CDN.
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