https://www.kitguru.net/gaming/matthew-wilson/diablo-2-resurrected-server-issues-partly-due-to-legacy-code-from-original-game/ In a blog post explaining the current server issues, Blizzard said that these outages “have not been caused by a singular issue” and that each problem is being tackled as it arises. Alongside squashing these bugs, the team is also working on “longer-term architectural changes”.
The post goes on to explain that in an effort to stay true to the original game, Diablo 2 Resurrected still contains a lot of legacy code. One of these legacy services is “struggling to keep up with modern player behaviour”.
“This service, with some upgrades from the original, handles critical pieces of game functionality, namely game creation/joining, updating/reading/filtering game lists, verifying game server health, and reading characters from the database to ensure your character can participate in whatever it is you’re filtering for. Importantly, this service is a singleton, which means we can only run one instance of it in order to ensure all players are seeing the most up-to-date and correct game list at all times. We did optimize this service in many ways to conform to more modern technology, but as we previously mentioned, a lot of our issues stem from game creation.” Blizzard now has a team working on diagnosing issues and implementing fixes, not just for Diablo 2 Resurrected, but for the full set of Blizzard online services to avoid legacy code issues in the future. There is no timetable, but changes are being implemented and fixes are rolling out consistently, so hopefully soon, Diablo 2 Resurrected will have much less downtime.
Let's hope the updates continue until the server issues are completely solved.