How We Scaled Our Infrastructure for 20K Players in the Counter-Strike Major Qualifiers

Explore our solutions for hosting the Counter-Strike Major Qualifiers, featuring robust server scaling, DDoS protection, and optimal connectivity.


The Counter-Strike Major Championships is the most important event for Counter-Strike players, attracting up to 20,000 participants. This tournament is open to all, starting with an open qualifier where any group of five can form a team to compete for a spot in the tournament. It’s a hugely popular esports event, with the PGL Major Stockholm 2021 reaching a peak viewership of 2.7 million viewers.

For the PGL CS2 Major Copenhagen 2024 Qualifiers, which started on January 8th 2024, we were approached by Challengermode, a platform for organizing esports competitions, to set up the Counter-Strike 2 servers needed for the event. In this article, we’ll explain in detail how we scaled our infrastructure to successfully host this tournament. 

Services used:

Counter-Strike 2 Servers
DatHost API

Challenges in Hosting Large-Scale Tournaments

Organizing large online tournaments like the Counter-Strike Major Championships, where players from all over the world join, is challenging. Here’s some of them:

Server Scaling: The nature of hosting tournaments often involves large and unpredictable shifts in player numbers. This unpredictability necessitates a server infrastructure that can be quickly and automatically scaled up or down. Successfully adapting to these variations in real time is an important aspect of maintaining smooth operations. 

DDoS Attacks: In the world of online gaming, DDoS (Distributed Denial of Service) attacks remain a persistent threat. Due to the unique nature of gaming connections, these attacks have evolved into more sophisticated forms, making them more challenging to defend against.

Latency Issues: Connecting players worldwide poses a significant challenge due to it being dependent on player’s individual internet connections from hundreds of different ISPs. Ensuring effective network routing is essential in this context. Low latency servers and excellent network stability are critical to mitigate the risks of network issues, which can greatly affect the gaming experience.

Getting Ready and Crunching the Numbers

Our task for this tournament boiled down to three essential requirements:

  1. Worldwide Server Coverage: We needed to provide servers in 21 different locations across the globe.
  2. Numerous Servers: A whopping ~2000 Counter-Strike 2 servers were required in total.
  3. Zero Lag Gaming: Above all, we aimed to deliver an experience free from any lags.

To meet these requirements and guarantee the best possible gameplay, we made a strategic choice: We deployed bare-metal servers equipped with the latest-generation CPUs, including the 3rd Gen AMD EPYC and Ryzen 7000 Series processors. These high-performance CPUs were essential in ensuring that we could host highly competitive 64 sub-tick Counter-Strike 2 servers. Leveraging our advanced automated server orchestration, we efficiently deployed over 50 of these servers swiftly. The rapid deployment was instrumental in managing the scale of the tournament, accounting for the needs of up to 20,000 players worldwide. 

We already have a lot of data on resource consumption for Counter-Strike 2 servers as we host thousands of servers every day. However, in this case with specific broadcasting requirements, we had to carefully test and calculate the performance needed beforehand to ensure a flawless experience without overload. When testing the load, there are three key measurements we’re looking for:

CPU Load: We closely monitor CPU usage for the tournament’s specific configuration. Given the variable load experienced by Counter-Strike servers throughout a match, we collect multiple measuring points to accommodate all scenarios. 

RAM Usage: Another important consideration was determining the RAM required per server instance. The tournament’s CSTV requirements (Counter-Strike server’s built-in broadcasting tool) varied from a standard setup, necessitating additional RAM to maintain optimal performance.

SVMS Value: This metric holds immense significance in Counter-Strike server performance. It represents the time, measured in milliseconds, needed for a server simulation step per networked frame. To ensure seamless gameplay, the SVMS value needs to be kept below 15.625ms. This enables the server to process 64 packets per second, matching the rate of a Counter-Strike 2 server.

Achieving Optimal Network Connectivity

In fast-paced FPS games like Counter-Strike, a reliable network connection is crucial for fair play. Our challenge was to connect tens of thousands of gamers worldwide, each using one of over hundred different Internet Service Providers (ISPs). This is a complex task and therefore is one of our main priorities. 

Our approach involves using data centers with exceptional connectivity. These data centers are strategically located and offer direct links to over 3000 local ISPs and 15 major transit providers. This extensive network ensures not only low latency but also, more importantly, stable connections that remain consistent throughout the match. Such stability is key in preventing disadvantages during the match due to fluctuating network performance. 

On top of this, our data centers are also equipped with robust redundancy. Each of them is connected to at least three different ISPs, with some, like our Frankfurt location, connected to over 10 ISPs. This redundancy is key to maintaining uninterrupted connectivity, even in the unlikely event of an ISP outage.

In addition to these connectivity measures, our data center’s defense system is structured around a robust, multi-layered strategy, ensuring the highest level of security and a seamless gaming experience.

  1. Edge Layer Protection: This first line of defense is crucial for mitigating volumetric DDoS attacks, including NTP, DNS, and Memcached amplification attacks.
  2. Middle Layer Protection: The second tier focuses on warding off L4 protocol attacks, such as TCP SYN, TCP ACK, and GRE flood attacks.
  3. DPI (Deep Packet Inspection) Layer: The final and most advanced layer inspects the payload of every packet targeting a CS2 server. It verifies the legitimacy of CS2 traffic, rejecting and dropping all non-CS2 packets before they can reach the server.

This structured approach is crucial in maintaining uninterrupted and secure gameplay on our CS2 servers.

Outcome and Results

Real-Time Server Scaling and Management
For Challengermode, handling up to 2000 servers was a potential logistical nightmare. However, thanks to our feature-rich API, the process was not just manageable – but impressively seamless. The API can automate a wide range of tasks – from server creation and relocation to real-time server communication and downloading of replay and log files.

Our API is built for scale and processes millions of calls daily without any issues. During the tournament, there wasn’t a single failed operation, launching servers within seconds of each request. 

Robust DDoS Protection in Action
Throughout the tournament, our proactive defense mechanisms faced numerous attacks, characterized by millions of packets masked as legitimate traffic. Our L4 protocol-based protection successfully mitigated these attacks, keeping the servers up and running smoothly without any impact. 

Our results speak for themselves: even when servers were directly targeted (which happened several times during the tournament), our defensive measures ensured uninterrupted gameplay, maintaining the competitive integrity of the tournament. 

Server Performance Insights
Focusing on the EU Open Qualifier on January 8th 2024, here’s a detailed view of our server performance:

Players Participating: 4220
Server Locations: 🇩🇪 Frankfurt, 🇫🇷 Paris, 🇳🇱 Amsterdam, 🇬🇧 London & 🇸🇪 Stockholm

Our monitoring extended beyond the bare metal machines to individual virtual instances. During every match, we tracked each player’s ping and packet loss data, to ensure optimal network performance. We also closely monitored the SVMS value to ensure that each server’s simulation step time remained well below the critical threshold.

Here’s a snapshot of our performance metrics during the qualifier:


In closing, we successfully hosted the PGL CS2 Major Copenhagen 2024 Qualifiers servers thanks to our innovative solutions and dedication. Our robust infrastructure and advanced API ensured a smooth experience for all participants, with up to 20,000 players competing.

Looking forward, we’re excited to continue using our powerful infrastructure for scaling gaming servers. As the esports industry evolves, we remain committed to delivering exceptional gaming experiences and setting new standards for the future.