Earlier this summer, we talked about players experiencing poor online match quality caused by DDOS attacks targeting our game servers, along with other server performance-related issues. Released across multiple game and server client updates over the last several weeks, we have deployed a series of fixes designed to neutralize popular DDOS attack methods, while ensuring that the bad actors behind these attacks are not rewarded for match disruption.
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⁠First, we made adjustments to how incoming connections are treated by the server. With this change, many of the most popular DDOS attack methods, which involve flooding a server with hundreds or thousands of connections at once, are ineffective right from the start. Second, we changed our server infrastructure to dramatically reduce the chance of a targeted match being affected.
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⁠Along with these improvements, we also changed how our game servers treat player disconnections associated with DDOS attacks. The game server will now disconnect all players in this scenario at the same time, and award everyone with a No Contest. This means attack victims no longer see an MMR loss — which is especially important in Competitive lobbies — and bad actors don’t see an MMR gain.
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⁠With these changes now live for several weeks, some players may have already noticed an improvement in match quality. DDOS attacks not only target a specific match, but have the potential to impact other matches hosted on the same server hardware, also known as the “noisy neighbor effect.” By neutralizing these DDOS attack methods, we’ve seen a major improvement in online match quality for all players — regardless of if their match was being targeted or not.
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⁠We are keeping a close watch on new attack methods if they appear and become popular so we can neutralize them as quickly as possible. We are also still mid-stream on some server hardware changes and improvements that we’ll complete later this month.
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⁠We appreciate everyone’s patience as we’ve worked on and implemented these changes, and we hope you make the most of them through the last weeks of Season 15 and beyond.