Object to object messages and script lag

[Poltergeist Azarov]

Yesterday i realized in a sim, when there are many agents like 80, object to object messages are failing some ways. When this happens, time dilation is ok, frame_number is ok(not freezing) but looks like scripts are working very slowly. In this case the server-object is releasing queued messages which is sent by using llregionsayto by clients. 
My question is, what slows down the scripts exactly? The CPU time consumed by agents in the sim? How to avoid the queue problem when scripts are working very slowly? 

[Nova Convair]

The sim server handles avatars, physics, chat, network and alot of other activities. When all of that is done the rest of the time in a frame is used to run scripts.

Ctrl-Shift-1 opens a statistics floater with alot of info. Check the script execution. If that is - in a crowded sim - at maybe 20% - that means that only 20% of the scripts are handled in every frame. So every script will run at about 1/5th of its normal speed.

Another thing is the message buffer. I already tested it by firing out and receiving many 1000 messages in a very short time. The sim buffers a few 1000 medium sized messages. Every message that exceeds that buffer is gone.

Now imagine alot of traffic, chat, messages and slow running scripts. That can hit the limits.

[Poltergeist Azarov]

Thank you. So how would you avoid the problem? Script slows down alot due to agent count, every client needs to send a message to server at each 25 seconds. (We can say client count gets up to 50 sometimes). 

[steph Arnott]

"How to avoid the queue problem when scripts are working very slowly? " you can not.

 

[Nova Convair]

Depends on the details of the script operations.

With 50 avatars it's an average of 2 messages per second. Thats nothing. But if all send at the same time thats 50 entries in the scripts event queue which has a length of 64. Another point to think about.

A script can receive 12-15 messages per second. (at 100% script execution @ the last time I checked that) So it will process 50 messages in 4 seconds but only if the processing time for each message is near zero and without any lag of course. Another point to investigate.

If messages are expected at a specific time - there are delays of a few seconds possible under this conditions.

 

[Rolig Loon]

Steph's right.  Scripts cannot lag a sim, because they have the lowest priority for server resources in each frame.  They can lag each other, though, and all other demands (primarily managing avatars) can take enough resources to slow scripts to a crawl. The only solution, really, is to reduce traffic in the region.

[Poltergeist Azarov]

Thank you so much everyone. 

As i see so far, as much as user count increases up to 60, script run is around 2%... Looks like they run at their lowest performance of 100%, am I right? In this case, what causes bottle neck is clear enough i think. This makes me think i will need to divide hard processes and distribute to clients themselves. 

[steph Arnott]

Have no idea where you get those results, but the simple fact is scripts are at the bottom of the pecking order and agents moving around at the top. Which clearly makes sense.