Strange performance issues

[TeoTwawki]

Last night a player had some serious lag, and I was able to log in and look. I experience no lag on my own solo. But I could see he was lagged. He'd engage and basically stutter like someone with network lag would.

I joined his party, and I instantly got R0 followed by all my commands taking nearly half a minute to fire off. I dropped party, and instantly I was back to normal.

I had him break party, full shutdown all characters, log back in and reform party - his party was then normal for several minutes. He noted that each character added after the second slowed him down just slightly, but was nowhere near as bad as before. After several minutes though it was getting noticeably bad again. I in game check'd his character and instantly lagged to hell for several minutes. I went back to normal after those minutes.

I dunno wtf is going on. This server has good hardware a fat internet pipe no bottlenecks and no source edits. Lag seems to "build up" for players during their parties. I believe this is the same problem complained of in Issue #2179 I've seen some isolated solo players complain of lag too, but I myself only see it in parties that have been on for awhile.

[whasf]

Did you notice any CPU usage spikes on the server's .exe when it was lagging? If you can, attach a debugger to the process and see if there is anything the server is doing to cause it.

[kjLotus]

if the server is sending out packets faster than it's allowed to process them (ie. more than the 1300 byte limit per 400ms) then you'll see stuff like that happen

there might have been something blasting his party with packets (status effect updates? not sure) that could do that

another thing to try is logging packets, or even just checking the R number in the top right of the client, or print whenever the "packet too big" condition is tripped and the server splits the packet queue