Combat Log Changes with Patch 10.2 - Measures to Prevent Out of Game Overlays
Blizzard pushed a number of changes to how the combat logging works to the Patch 10.2 PTR a couple of builds ago. These changes seem aimed at preventing the use of out-of-game overlays similar to those used by some players in Aberrus.
Currently, the combat log file in your system is updated very frequently with new combat information almost as soon as it happens.
In patch 10.2, with this change, the game is keeping all combat log information in memory and only writes it to the file once combat ends.
This change breaks how current Out of Game Overlays work, since the data they use now isn't in real-time, only existing once combat ends. However, this approach causes some new issues to surface.
The main issue is that if your game ever crashes or you reload mid-pull, all combat data stored is lost. This seems to usually mean only the current combat session, so its impact is not widespread.
Another issue is that combatlogging will become more restrictive, as many computers will not be able to handle storing all data happening in a combat session and then dumping it all to disk once it ends. This is especially relevant for raid content, where some encounters can last 10-15 minutes and have 20 participants, meaning you're dealing with hundreds of megabytes of data in memory which, at combat end, need to be instantly written to disk, possibly causing screen freezes or crashes in extreme cases.
