SL project updates 41/2: server, HTTP, Group Chat

Pigeon Island, Neverending; Inara Pey, June 2014, on FlickrPigeon Island, Neverending (Flickr) – blog post

The following notes are taken from the Server Beta meeting held on Thursday October 9th, 2014. The transcript is available here, and the support agenda notes here.

Server Deployments Week 41 – Recap

  • Server deployment thread
  • The Main (SLS) channel and the Snack RC received the same server maintenance package as had been deployed to the three primary RCs in week 40,which fixes a bug related to viewing parcel details in gaming regions
  • There was no deployment to any of the primary RC channels (LeTigre, BlueSteel and Magnum).

CDN and the Snack RC

There are now some 270 regions on the Snack RC and which use the CDN for texture and mesh data fetching. The majority of these are mainland regions, although there is still no public list of all of them. Those who would like their region added to Snack are asked to contact the Lab at

If you’re using a TPV that can display region details in a dialogue box following a region crossing, you can use it to identify regions using the CDN, or you can check the About Land floater for the region you’re in. In both cases look for “Second Life RC Snack” in the region’s descriptive text. If you see it, the region is using the CDN.

Group Chat

Simon Linden’s work to both reduce the volume of additional group chat information messages (people joining leaving group chat sessions, updates to the group members list as people log-in or out of SL), and the frequency with which they are sent appears to have satisfied the Lab that they will produce some measure of improvement. There has already been a deployment of the updates to some of the back-end chat servers, and according to Maestro Linden, it is anticipated they should be on all of the chat servers some time in the next week. There may be more to add to this following the TPV Developer meeting.

HTTP Pipelining

Monty Linden: HTTP guru
Monty Linden: HTTP guru

The new HTTP pipelining viewer (referred to by the Lab’s QA team as the “weaponized” viewer, it is apparently so slick), is due to hit RC status. “Project Drano”, as Monty Linden, who has been spearheading the HTTP work over the last 2+ years, jokingly calls it, offers both improvements of its own and should further assist in data downloads via the CDN. Commenting on the viewer, Monty said:

The next viewer adds HTTP pipelining support to mesh and texture fetches. This allows multiple asset requests to be issued without waiting for intervening responses from the server, and it goes very far towards making client-to-server ping time irrelevant in throughput metrics. It’s a huge step on its own making our services perform as well as they can. Combined with CDN it’s even better. I won’t mention specific numbers but a region can show up in a very few seconds … Right now, we plan on skipping the project viewer stage. We’re going out the door [as an RC] once it passes QA (maestro heading that up).

Mesh fetching via the CDN should see an improvement because the viewer-side throttle of 100 meshes/second has been removed (this won’t affect non-CDN regions, as the throttle is also applied server-side on those).

As well as the core HTTP work, Monty has also done some work on inventory fetching within this viewer, particularly the code which is used to initially populate the inventory floater. This has been converted to use HTTP, and reduces the number of connections it uses. Again, no precise figures were given, but it should lead to improvements in inventory loading in situations where inventory data has been removed from cache (see the Firestorm wiki for information on removing inventory data files from cache). In one test with no inventory data, Monty saw a 100K inventory load around 10 times faster with the new viewer.

Whirly Fizzle (based in the UK) carried out inventory load tests for an 105K inventory between what was at the time the SL release viewer and a pre-release version of the HTTP pipelining viewer, both starting from a clear cache, and achieved some impressive results:

  • Second Life 3.7.16 (294015) Sep 10 2014 11:08:26 (Second Life Release)
    • Session 1: 16 mins 28 secs
    • Session 2: 17 mins 53 secs
    • Session 3: 17 mins 18 secs
    • Session 4: 17 mins 51 secs
  • Second Life 3.7.17 (294571) Sep 26 2014 12:32:36 (HTTP pipelining viewer)
    • Session 1: 2 mins 29 secs
    • Session 2: 2 mins 17 secs
    • Session 3: 2 mins 11 secs
    • Session 4: 2 mins 27 secs

I tend to have a very organised inventory, old / no longer used items are boxed, and anything not used in 6 months is similarly boxed (see: zdrop). Thus I only have an “active” inventory of around 10K (9,140 items at the moment), out of a total of around 70-100K. However, even with a “small” inventory like that, and working with a cleared cache, my results were impressive. The latest project version of the HTTP pipelining viewer ( averaged 9-10 seconds for inventory to download compared with an average of 2 minutes 50 seconds to 3 minutes for the current release viewer (

Again, overall mileage on inventory downloads will vary, hence why Monty is hesitant to mention figures. However, it is thought that those with excessively “flat” inventories should see particular benefit (although they’d also be better off nesting their inventory into groups of folders).

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