Rich and Andrew-Bugged objs that drop client kbps to 0

I am posting here as well as IM to try to catch either of you. I got another bugged obj this morning and I think I have an idea about it. I'll post all my data in case others have this problem as well.


I have had this problem for some time now. Have spoken to several Lindens about it but could never figure how it happens.
Well, after over a week of building, I "think" i have an idea on how the bugged objs occur.

Scenario:
Single, or a linked group of objects, usually 3 or more, gets "bugged" somehow and when clicked on to move them they knock the clients network speed to 0 and leaves you hang for 3 to 15 minutes.

Facts:

1. Bugged objs do not effect you until you try to move them. They can be edited.

2. Every time I got a bugged obj it was very soon after I got a "You cannot link these objects together. You do not own one or more of these objects." or something like that.

3. I never got a bugged standalone single object. Only after linking/unlinking did the singles get bugged.

4. Deleteing and recreating the bugged obj only removes the "bug" if you copied the obj Before it was bugged.


My course of action: This is what I think may be happening.

I assume I can only recreate this during a lag issue. So i intend to link/unlink as fast and as many objs as I can hoping for a bugged one.

I have had the EXACT same thing happen to me the last two days. I am working with a length of chain that has 13 segments. Four times now, I have received the same error messages that Stauf has been getting. Soon, like within seconds, I lock up and have to re-log. When I come back into SL, I get the message stating that my Sim is down and am logged in at a different location. Last night it went down and stayed down until I logged off at 11 LST.

Hope this helps with the problem.


-TK

I'm seeing a common denominator in all my bugged objs and what Tracey stated. Lag. Whether it be packet loss or sim ping it's always either of them that are very close wehn things get "buggy" with the objs. Also, while trying to link my objs with one that wasnt mine I got teh same type of symptoms. However I didnt go to 0kbps. What it did do is basically "un-own" my objs for a short time. This is the exact problem I got every time I tried to link objs together which resulted in a bugged obj.

Thanks for the info; I think it will help me find the source of the problem. I'll try Stauf's method for reproducing the problem.

I tried linking several objs and unlinking them while randomly hitting ctrl-alt-shift-L to drop packets with no luck.

The only thing that came close to reproducing it was when I tried linking an obj Richard had made with several of mine. It dropped ownership of my objs for a short time. This was the same error msg I got on every bugged obj I created. The "I can't link/delink because I didn't have ownership of all the objs"

Thanks to Stauf Arbuckle's Corvette project and Xavier VonLenard's rose... I've got some good ideas about how to fix this.

Now if I could only get back to bugfixing!

In the meantime I have some advice...

1. Don't make lots of complex objects that are in deep interpenetration with each other. If you were to move one of these objects just a little bit to one side you could end up with a sim-bomb.

2. If you're worried about sim performance, use convex geometry when possible. Although the geometry of tubes and torii is more dense, making the objects look smoother than cylinders,... in fact they ARE more dense -- both the server and the client work harder when loaded with lots of complex objects.

3. I think I know how to reduce this problem, not eliminate it, so item 2 is worth keeping in mind when modelling objects.

A complex object is any concave object, such as a hollow sphere. But some objects are more complex than others: a hollow, twisted, cut, tube is about as complex as they get in SL.

A sim-bomb is an object whose physical and/or scripted properties cause the servers to slow to a crawl, or grind to a halt.

I've fixed most of the problem in the upcoming release. In the meantime here is a recipie on how to reproduce the bug and bomb the sim (explained here so that you can AVOID doing it):

1. Make several complex primitives: cut, hollow tubes work great, but if the primitives aren't complex enough, just make twice or four times as many.

2. Start moving the primitives such that they all occupy the same spot. As you move them and increase the number of overlaps you'll notice the sim start to become unresponsive (you may have to try to move your avatar to detect the lag of the sim).

2.1 Basically, the sim will lag more as additional complex objects are moved into interpenetration, but it ALSO scales with the number of movements that are being made. So, if you just slam the position of an object into the middle of the collection, it will lag once (you might not even notice it). But if you slowly move the object into place the sim will lag A LOT. If it lags for more than 60 seconds it will crash.


Thanks to Stauf for helping me fix this bug. I used his old Corvette dashboard (with the big tube) to reproduce this on my development machine.