Santaurio, Cala del Barronal (Flickr) – blog post

Server Deployments week 34 – Recap

There was no deployment on the Main (SLS) channel on Tuesday August 19th. All three RC channels received the same server maintenance project on Wednesday August 20th, aimed at fixing a crash mode.

There may be news on the crash mode fixed in the RCs once it has deployed to the Main (SLS) channel in week 35.

Upcoming Server Deployments

There will be a new server maintenance package deployed to the RCs in week 35, which includes a couple of visible changes:

SVC-2262 – “Incorrect height value in postcard which sent from above 256m” (a postcard being a snapshot sent to e-mail)

A “re-fix” for BUG-6466 – “Numbers expressed in scientific notation and include a plus sign in the exponent are not parsed as JSON numbers by LSL”, which was thought to have been fixed a while ago, but which in fact resulted in BUG-6657 – Valid JSON numbers like 0e0 no longer valid after 14.06.26.291532. prompting the original fix to be rolled back.

SL Viewer News

TPV developer Niran V Dean has been working on a new unified snapshot floater which encompasses the “standard” floater, plus the Flickr, Twitter and Facebook upload options, under STORM-2040. Those who use the most recently releases of Niran’s Black Dragon viewer will be familiar with the approach, as he initially worked on the idea in that viewer.

The work is now progressing to a point where we should be seeing the fruits of his labour in the near future. In the meantime, I’ve previewed the work as it stands at the moment.

Texture and Mesh Fetching CDN

As reported in my last TPV developer meeting update, the Lab is looking to move texture and mesh fetching to a content delivery network (CDN). If successful, this approach will see texture and mesh fetching bypass the simulator entirely, being routed instead directly between the viewer and asset servers via the CDN, which should see improvements in the speed and reliability of such transfers. Explaining the new approach further at the Server Beta meeting on Thursday August 21st, Maestro Linden said,

The viewer currently fetches all meshes and textures through the sim, which gets them from the asset server, and the sim gives the viewer a ‘capability’ URL, which the viewer uses for fetching. However, with this change to use the CDN, the sim instead gives the viewer the URL of the CDN, and the CDN has hosts all over the world.

It’s good for two reasons: 1) the sim isn’t burdened with texture/mesh transfers; 2) you’ll often have lower latency to the CDN than the sim, which means more speed.

Allowing for the fact the Lab is accessing the service through their own network (although the CDN is a commercial service), both Maestro and April Linden report it as being a noticeable improvement on things, with texture and mesh fetching having double the performance compared to the current means of fetching via the simulator. Initial results of testing from Europe show similar improvements.

The Server Beta meeting agenda has further information on new method for mesh and texture fetching, including details on the Aditi stress test regions (one for textures, one for meshes), and those wishing to try them out are invited to do so. No special viewer is required in order to carry out testing at present, and the agenda includes notes on what to do. Note that the test regions are set to no-build so that people don’t rez extra things that would skew results; they are also likely to be limited in terms of the maximum number of avatars able to access them at one time.

If / when the new approach is more broadly rolled-out, people will be able to see which service (CDN or via the simulator) they are using is to set Develop > Consoles > Capabilities Info To Debug Console. Those using the CDN will see the GetMesh, GetMesh2, and GetTexture URLs will all be http://asset-cdn.aditi.lindenlab.com/, while those using the current method will see it give some URL pointing at the sim host. However, we’re still some way from seeing the new service deployed further than the Aditi test regions.

Should this work prove successful, and once it and other HTTP work such as pipelining, as being developed by Monty Linden, is completed, the Lab hopes that they’ll have a fast, robust series of HTTP services such that they can look to retire UDP texture fetching – although this will be some way down the road, and in the interim, UDP will offer people something of a fallback for texture fetching should they have issues with HTTP as the various new services are deployed.

Skill Gaming Regions

Simon Linden reported that the first of the Skill Gaming regions has arrived on Agni (the main grid). Called Crunchy, it doesn’t have any gaming parlours or anything on it, but appears to be set-up for testing (such as accessibility). There are a few things going on there, most under the control of Gecko Linden. Also, and as pointed-out by Simon, the first skill games and operators have started to appear on the Lab’s Skill Gaming Participants wiki page.

Group Chat

Work has resumed on group chat after a brief pause, and the Server Beta meeting saw a very brief test take place. The aim of this was to test delays that have been introduced into the members list updates sent by the chat server.

As I’ve previously reported, one of the biggest issues of chat delays in group chat sessions is to do with the numbers of updates the chat server has to send as people join / leave session and log-in / out of SL, changing their online status within the groups they’re a member off. Recent changes to the code are intended to queue these updates and reduce the load they are placing on the servers, interrupting the flow of text messages.

The test was brief, but appeared to give Simon Linden enough information to be able to go back and poke at things some more.

Group Chat Server Issues

There have been further reports of group chat servers at times becoming non-responsive. This issue was initially raised in week 33, after the server supporting all group chats with a key starting with “b”. A further issue was identified at the start of week 34 affecting the server supporting all group chats with a key starting with “d”. While the Lab is aware of ongoing problems, there is also a request for JIRAs to be submitted on specific issues.