On Wednesday October 15th, Monty Linden blogged about his HTTP work and the CDN, using the rather unusual title, The Sky Over Berlin (and Elsewhere). It’s a great piece of reading, although I can’t help thinking that Monty’s sign-off at this end of it would have perhaps suited the subject matter far better: nous sommes embarqués – “adventure is ours for the taking”!
The first part of the post recaps on Monty’s initial work in improving Second Life via the HTTP project. This started as far back as mid-2012, with the first pass focused on improving the mechanism by which textures could be obtained for rendering via HTTP, which entered widespread use around November 2012, with the release of the 3.4.3267135 viewer.
This work was followed by Monty labouring to improve mesh fetching as well, and to improve the overall reliability of HTTP, which I blogged about in March 2013.
At the start of 2014, Monty blogged on his work up to that point, and looked ahead to future activities. As a part of the post, he included a graph showing how the work carried out up to that point improved texture and mesh request handling.
In his latest post, Monty picks-up where his January post left off, demonstrating how more recent improvements are starting to improve things further – notably through the use of HTTP pipelining (the release candidate viewer for which has now been issued – see below), and the ongoing deployment of the Content Delivery Network service for texture and mesh data delivery.
All told, Monty’s work has been a remarkable undertaking which benefits Second Life enormously, and helps to set the path towards possible further improvements in the future. As such, he really is one of the heroes of Second Life and the Lab.
HTTP Pipelining RC Viewer
The HTTP Pipelining viewer was issued as a release candidate viewer shortly after Monty’s post went to press.
Version 188.8.131.525372 enables the viewer to issue multiple asset fetches on a connection without waiting for responses to earlier requests. This should help inprove things like initial scene loading quite aside from any additional benefits gained through the CDN deployment work. In addition, the viewer includes improvements to inventory fetching, as Monty noted in his blog post:
The HTTP Project has focused on textures and meshes. But the inventory system, which maintains item ownership, is often described as… sluggish. So as an exercise in expanding the use of the new HTTP library, the pipelining viewer was modified to use it for inventory fetches. As with textures and meshes before, inventory is now fetching in the ‘C’ region of its specific performance graph. The difference can be surprising.
Having had the opportunity to test the pipelining viewer somewhat prior to its appearance as an RC, I can attest to this. While I keep my “active” inventory to a modest size (around 10,000 items unpacked, the rest boxed until needed), I found that an inventory download with a cleared inventory cache (nothing saved on my computer) averaged 9-10 seconds using the pipelining viewer, compared with an average of 2 minutes 50 seconds to 3 minutes with the current release viewer (184.108.40.2064959). Whirly Fizzle, using a 105K inventory had even more impressive results: with a cleared cache, her inventory loaded in under 3 minutes on the pipelining viewer, compared to 16-18 minutes on the release viewer.
The release notes for the viewer contain additional information about the updates, again written by Monty, and these make worthwhile reading alongside of his blog post.