Debugging a Second Life Region’s Lag


As is typical in SL some information is out dated. As is also typical some things are ambiguous and poorly defined making various understandings possible. None of the lag producers are simple are straightforward any longer. The simple stuff has been corrected.

Over the last two years there has been so many changes it is difficult to keep up on what is outdated and ineffective. There certainly is no lack of outdated advice being handed out.

Many of the fixes and improvements are scale-of-problem reductions rather than eliminations of a problem. This makes it confusing when some of us say something has been fixed and others say the problem is still there. An example is SSA (Server Side Appearance – baking). It was implemented to fix avatar bake fail. It did that. But, you still see the symptom of bake fail. But, the bake fail we see now is caused by other problems. The ovens are fixed and they do work. But, if the Inventory System fails to supply a texture to the oven, it cannot be baked and we see a bake fail.

The complexity is in simplifying our idea of what bake fail is. Bake fail has many causes and one set of causes, the ovens, has been fixed. But, other parts of the system can still cause bake fail.

One of those parts is the connection to SL. That connection can also contribute to region lag. Users having boosted their mesh download thread counts have contributed to a huge amount of system lag. When one of those users or worse several of them arrive in region they can kill performance. If you are trying to figure out what is wrong in a region they can really confuse you.

As newer viewers come out the value of mesh download concurrent threads is likely to be clamped to some max viewer side. Or if that doesn’t work out the servers may limit the value.

Monty is working to improve the connection between viewer and SL servers. As that gets implemented we will see less bake fail and faster texture render and region loading of meshes.

My point here is that debugging lag in a region is an ever-changing process. Unfortunately the Lindens don’t tell us everything that is changing. Plus there are lots of people that do not stay current and repeat old information, like clear your cache, which often aggravates the problem rather than resolving it. Cache clearing when not needed throws extra load on the system for no reason.

Threads like the one Innula started are needed every so often. If you have new information to contribute, add it to her thread. Plus, I like helpful information in the comments here.

6 thoughts on “Debugging a Second Life Region’s Lag

  1. An important point for those readers here who are not sophisticated in their understanding of lag:
    Your Lag is not the same as Region Lag. Region Lag will contribute to your experience of lag but there are many other contributing factors. Among them:
    Your settings.
    Your network connections (all the way through LL’s network to the servers and back).
    Your Hardware.
    What is around you in the region, especially other avatars.

  2. Ctrl-Alt-Shift-T is handy, thanks for mentioning it. I wonder if it messages you about all the textures on the object, or just the unrepeated: I do care more if my boat have hundred of 1024 textures, that if it have just one 1024×1024 texture repeated a hundred of times. Maybe server side there is no difference.. but for GPU memory for sure there is.

    • It does list the faces the texture appears on in a single prim. But, I don’t see any reference for the same texture appearing on multiple prims.

  3. So – since the topic of textures has come up- here are TWO questions that drive me nuts…
    1) if someone rezzes a prim – for this example a cube – and applies the SAME texture to every face, and the cube only needs a texture on 1 face- does the server and or viewer have to work harder to redisplay the texture multiple times even though its the same exact asset?

    2) If a texture is applied to a prim surface that is never displayed (burined under other prims) does it “count” – and would it be better off deleted?


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