Second Life News 2014-46 #2

There was not much new news revealed in the Beta Server User Group meeting this week. We seem to be getting sparse news, not that Lindens aren’t talking. There is just not much to talk about.

Blood Letters 2014

Blood Letters 2014

CDN

The rollouts to the RC Channels were tweaks to the Content Delivery Network (CDN). When Whirly Fizzle asked,  “Are those CDN changes something users will notice?” Maetro Linden described them as: “No, it’s just a way to reconfigure the CDN URL if we need to. Eventually there’s a plan to make that point at a more ‘dynamic’ hostname, which is still being set up. However, there is some viewer work meant to address some of those CDN issues, to address BUG-7698 and similar ones.” 

I assume he means in regard to the gray renders many of us are seeing. The Lindens and CDN provider are aware of the problem and working to resolve it.

BUG-7698  – Textures much slower to load on a CDN region than on a clone of the same region not running CDN. Bug filed by Whirly Fizzle, who did some awesome testing to help resolve this problem.

The steps for producing the bug and measuring performance:

  • Delete settings folder so viewer settings are on default.
  • Launch viewer and set the following settings
    • Draw distance – 512m
    • Cache size – Maximum 9984 MB
    • Maximum bandwidth 1500
    • Close viewer to save settings.
  • Delete cache folder before each run.
  • For each run, start a timer as soon as the login button is clicked.
  • Once logged in, do not move camera or avatar.
  • Open texture console.
  • Stop timer once texture console is empty and all textures are fetched.
  • Note down the times.

Some are doing testing with FastCacheFetchEnabled set to false. For the typical user this setting should be left alone, TRUE by default.

Whirly also said, “Fast-pipe with pipelining enabled def works better for me on CDN regions. The long texture loading stalls have pretty much stopped.”

The discussion about CDN and HTTP Pipeline touched on numerous problems and behaviors that we are seeing. Whirly points out those seeing corrupted textures since CDN all have “Invalid Content-Range header encountered (Core_4)” errors all over their logs for mesh and texture fetches.

Viewers

I’ll get to these later. For now suffice to say I’m having problems with my viewers.

Viewer Stats PING

It has been some time since this came up for discussion. Viewer ping is not the same PING as the network ping thought of by most when the word ‘ping’ is used. PING in the viewer is more a measure of composite latency, my name.

If you use both viewer (UDP) and your computer’s (ICMP) ping at the same time you will get very different results. Viewer ping includes viewer and SL server performance factors. Regions that have Time Dilation issues always have much higher ping times.

Also, packet loss will drive viewer ping into the thousands of milliseconds. But, computer ping time will remain fairly consistent in the face of packet loss.

The viewer sends a Start Ping Check and receives a Ping Complete Packet and uses the time between sending and receiving to calculate ping time. If the Complete packet is lost the value distorts. It also distorts if the severs is too busy.

All this means is that viewer ping is NOT a measure of network performance, but does have a aspect of network performance included.

Mæstro Linden describes it this way, ‘I suppose it’s more like..  “if I press the jump key, how much delay will there be before I start to see my avatar begin to jump?”’

No Change Window

We are coming into the American holiday season. Next week there will be no server rollouts and that likely means no region restarts, main or RC.

The same will likely be true for viewers too. IF you are thinking news and forward movement is slow this week, next week we won’t much of anything to talk about.

Next week’s holiday in the U.S. is Thanksgiving, a time when the first colonists in America were trying out communism. It wasn’t named that until about 200 years later. The experiment was one of the most pure cases of communism-socialism tried to date and they nearly starved to death. (Reference, reference, reference)

4 thoughts on “Second Life News 2014-46 #2

  1. “We are coming into the American holiday season. Next week there will be no server rollouts and that likely means no region restarts, main or RC.”

    Today, Linden Lab announced on the Grid Status page, that from Monday, November 17, there will be a full week of scheduled maintenance with one or more restarts for each region every day. Did Linden Lab not discuss this topic in the Beta Server User Group?

    second try, now with working link 🙂

  2. Thanks for the reply. Strange that Linden Lab has not addressed such a heavy server maintenance in the meeting.

    It looks like an important modification. Maybe they will switch to a new operating system. Or it has something to do with the Experience Tools.

    • This may be the operations team doing hardware upgrading or data center organization. So, the engineering Lindens we talk with would sort of be out of the circle. Similar things have happened in the past.

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