New Second Life Network Architecture

Monty Linden posted an update in the Technology forum. See it here: Second Life Network Architecture.

Second Life Network Architecture - 2015

Second Life Network Architecture – 2015


To the left (in red) are pieces of the viewer.  To the right (in blue) are simhost/simulators and other backend services.  And at bottom (in green) are new CDN services.

Solid lines with arrowheads are communication paths, either UDP or TCP/HTTP.  Dashed lines indicate legacy communication paths that are now or soon will be deprecated, obsoleted and/or deleted.

Ball-and-stick objects between a communication path and a text label indicate a viewer debug setting and the communication path or paths that setting influences.  These, too, are in solid and dashed flavors.  The latter indicating obsolescence.  And as always, at least one error crept into my diagram.  In this case, the ‘HttpPipelining’ setting only influences mesh and texture communications.  Inventory is currently unaffected by this setting.  [Image has been corrected – ed]

Generally, things are moving in the direction of simplification and less resource conflict.  The mesh and texture HTTP traffic, which is usually the greatest load, tends to part ways with the UDP traffic a few network hops after a user’s router or modem.  Lacking TCP’s throttling mechanism, UDP often wins in a fight (give-or-take the efforts of fairness algorithms along the path).  Allowing UDP to overrun the path between viewer and simulator does still degrade the experience and the bandwidth setting remains an effective tool for avoiding this problem.

Other settings should generally be left alone.  A lot of bad advice was spread around in the community in an effort to work around throughput problems.  We’re trying to undo that history and get back on track with more typical (albeit aggressive) HTTP patterns.

Second Life News Week 20

From the Third Party Viewer UG meeting we get a little news. It was another short meeting.

What The......!

What The……! – by Simone Landers, on Flickr


RC Second Life Big Bird Viewer version – This viewer has fixes for some attachment-related issues. The Lindens are not anticipating any difficulties with this viewer, so this one should be moving to promotion as the default viewer soon.

There are some server side fixes for attachment problems that are in the works.  Continue reading

Second Life Server Updates Week 20

Server updates are coming slower than in 2013 and 2014. The Lab seems to be settling into an update every other week. This week the RC channels saw and update roll out, but not last week. The main channel did not get a roll out this week, but did last week.

Always Evolving...

Always Evolving… by Sombra Monroe, on Flickr

My thinking is that after 3 or more years of intense weekly bug fixing, the Lab has to be running out of bugs. In the last 30 days only 229 issues have been filed. Some number of those are duplicates. Of those 200 have been handled. There is probably some way to separate out viewer, web, and server issues. But, I haven’t tried. A quick count across the first page of issues gives me the impression about 20% of the issues are sort of server related. So, that is about 40 issues for the last 30 days and presumably 30 something of those are fixed.  Continue reading

Second Life: Catching Up

Being gone for almost 2 weeks, there is lots for me to catch up on. These are the things I found interesting.

Mer étincelante

Mer étincelante by Nunie-SL, on Flickr


I previously mentioned this. But, now the new avatar height and hover controls officially have their counterparts in the Linden Scripting Language (LSL): LLGetObjectDetails() and LLGetAgentSize(). See: New LSL support for Avatar Shape, Height and Hover.

A part of LLGetObjectDetails() is the flag: OBJECT_HOVER_HEIGHT – Gets the hover height of the avatar.
If id is not an avatar, 0.0 is returned. Normal values are in the range of-2.0 to 2.0 with a default value of 0.0. This value does not reflect the avatar shape’s “Hover” setting, only the dynamic viewer setting. Continue reading

Second Life News Week 15

This Friday (4/10) there was a Third Party Developers’ User Group (TPD UG)meeting. We have some news about Second Life™ from the meeting. The scheduled 60 minute meeting ran a little over 30 minutes.

Viewer Managed Marketplace (VMM)

Brooke Linden opened the meeting as Oz Linden seemed to have poofed. Brooke is telling us that they have started deploying parts of the Viewer Managed Marketplace server side. They hope to have a couple of parts rolled out later in the month. Then they can start what I’ll call an open beta. I take it this means it will be moving from the Preview/Beta Grid to the main grid.


087 by ʏoni, on Flickr

Meeting Schedule

Oz was suffering a bad throat and sounded horrible. So, it is no surprise the meeting was short.

The TPD UG meetings are normally every other Friday. Oz is planning to be taking some Fridays off. So, that regularity is going to be upset. Some meetings will occur very other Friday but some may be three weeks apart rather than two. This will mean, I think, Fridays off in place of a longer vacation period. It’s his choice. Continue reading

Second Life Servers Week 15

We aren’t hearing a lot about what is happening with Second Life™ development at the Lab. This usually happens when the Lindens are completing a well known project, like Experience Tools. Or they starting a new project they aren’t completely sure will fly and they are saying nothing.

Sakura Maiden

Sakura Maiden by Lucifer Lightbringer, on Flickr

In this case I think they are focusing on Experience Tools. It isn’t that they aren’t working hard and or not much is happening. It is more about how exciting is finding a ‘;’ that is in the wrong place? Not very. Plus there are a couple of things finishing up that I suspect are consuming resources. The Tools Viewer that is a representation of the change in compiler tools is one that has created a bit of a bottleneck. I think once it rolls out the bottleneck will break loose and we will see more features releasing.  Continue reading

Second Life Server & Viewer Update


A new version of RC Maintenance Viewer version is out as of 3/31. I am running it. I have had had little time with it. I can’t tell if it is a problem or if the Second Life™ servers were just lagging. Whichever it was, rendering was painfully slow. Every time I moved or turned my head FPS would drop to 5 or 6.

♥ Bubbles Life ♥

♥ Bubbles Life ♥ by cry wolf, on Flickr

Yesterday 3/30, RC Tools Update Viewer version appeared. This version is about the build tools related to Visual Studio 2013, Xcode 6.1 compilers used to build the viewer.  Continue reading

Second Life Bits 2015 Week 11


I’ve been missing User Group meetings. Yesterday I was finding a work-around for a business class HP Laserjet Multifunction Printer that kept forgetting where to send document scans. I decided HP has totally destroyed their driver & software download site. Frustrating. It used to be simple.

Daisa Daisa - Color Bust

Daisa Daisa – Color Bust by Nylon Pinkney, on Flickr

But, even if I had been at the meeting, there isn’t much news. As there was no package for the RC server channels last week there is no main channel roll out this week.  Continue reading