Tonight we experienced something very strange on one of our event servers. It is hosted along with a few other servers on a dedicated machine running Windows 2003 Server. It's bandwidth and performance should not be an issue (which it also has proven on many occasions).

Here are the details:

• About 40 seconds into the race there is suddenly an incredible amount of lag.
  
• All cars disappear on and off during roughly two minutes.
  
• Some cars disappear for 1 or 2 seconds, other 10-20 seconds.
  
• No one times out nor disconnects / gets disconnected during the lag, but,
  
• the lag stops as soon as [TDRT] Riise spectates.
  
• A race that started on another server (on the same machine) at exactly the same time didn't suffer from any lag.
  
• During the first one or two lap(s) of the race, there is something odd going on with the track textures (when tabbing between cars).
  
• The event logs of the server does not show anything out of the ordinary.
  
• The network and system resource utilization was constantly low throughout the race.

Server-side replays from the server in question (server A): race session - qualifying session - warm-up session.
Server-side replays from the other server (server B), that did not suffer from lag: race session - qualfying session - warm-up session.

Please note that the lag only occoured for two minutes during server A's race session. I'm just linking the other sessions in case they are needed.

Edit: There seems to be something wrong with replay of server A's qualifying session. Don't know it's related.

[TDRT] Riise had just finished our new TDRT ( Hi -resolution ) FXO skins and he was the only one who had uploaded it to LFSWorld. We were 4 TDRT cars on server A using this skin.
Some people from server B changed to server A after the qualification.
After 40 secs. some cars gets spun in T1 and their speed becomes under a XX Km/h and I wonder if a huge skin download started causing this massive lag seen yesterday.