More on LAG

[Steel DarKnight]

First of all, we're aware that some of you are experiencing lag since the publish of Age of Shadows. For that I'd like to apologize and explain what we're doing to improve things.

While reading this explanation understand that bandwidth usage and lag are related... more bandwidth usage tends to create more lag for low bandwidth users.

Here are the Age of Shadows features that do and will continue to use more bandwidth than Event 5 did:

- Customized houses are about 500 to 2000 bytes each and are cached client side in a persistent cache

- Item properties are about 20 to 100 bytes each and are cached client side in a temporary cache

- Floating damage numbers are small number of bytes (< 20)

Some details about what we're doing or have done to reduce the impact of these:

- Customized houses are about as optimized as they're likely to get right now. Each house is broken into slices and encoded using one of several algorithms, then each slice is compressed. The only further optimizations that can be made with regard to housing is for us to gradually ship each slice to the client instead of sending all the slices at once, and to turn off the standard packet compression/encoding for housing packets. Since I have yet to read one single complaint about customized houses causing undue lag, I have no immediate plans to implement those further optimizations. Further more the majority of the house-related lag appears to be due to the lockdowns and vendors…

- Items properties are the current target of our optimization efforts... these appear to be the major cause of the increased lag, and are what have been causing people to be blackholed. The size of the average item properties packet caught us by surprise, we had not originally intended to send so many properties, so our initial impact analysis was way off. We have a fix in QA right now to address this problem. We're now throttling the rate at which these packets are sent to the client so that when people enter vendor malls or recall to a popular place their available bandwidth is not overwhelmed.

- Floating damage numbers do not appear to have a significant impact upon lag, are are already as optimized as they're likely to be.

Those same features that can cause lag, can also cause the client to be completely overwhelmed with data resulting in a character becoming blackholed. We have a patch in QA to address this problem. I have refactored the server side buffering code to behave better in these situations. Once this patch goes live, naturally occurring blackholes at champion spawns, banks, and vendor malls should be rare. Also in this patch is a fix for the packet corruption problem that plagued many users (especially modem users.) This corruption is likely the cause of the majority of the recent random disconnects, seeing the character select screen in the middle of gameplay, and other miscellaneous weirdness. The reason why this bug appears to be more prevelant now is that it is only triggered when one of the server side buffers in near capacity… as we’ve been seeing lately with the increased bandwith usage of Age of Shadows.

In development is a fix that should address the famous multiple door problem (as it applies to regular buildings in UO) as well as a related cause of blackholes around places with too many candelabra, communication crystals, the Delucia bank, etc.

Right now I am focusing on more item properties optimizations, and weeding through out data stream to remove duplicate information. I anticipate having another batch of fixes in Publish 18.

Thank you for your patience in this matter,

Fertbert

* original post on Stratics UO Tech board... cross posting to uo.com boards... please watch for future messages on Stratics