MySQL for the Large Scale Social Games

We at DeNA (the largest social game provider in Japan) handle over 2 billion page views per day with MySQL. We heavily use SSD and tune Linux. We run non-trivial solutions such as non-stop, automated MySQL master failover. We also use MySQL not only as traditional RDBMS, but also an extremely high performance NoSQL. I’d like to introduce our MySQL solutions to make our social games scale better. The following topics will be covered.

• SSD and Linux deployment strategies

Choosing right Hardware components, configuring them properly, and optimizing Linux settings are very important for MySQL and other database server deployments. But they are frequently overlooked. I have seen many cases that H/W and Linux settings were wrongly configured on production environemnts. Changing configurations after going live is not easy. Some Linux settings such as I/O scheduler can be changed dynamically, but many of the settings can not be changed without stopping MySQL. It is important for infrastructure engineers to understand Linux and H/W tuning and monitoring best practices. I’d like to cover SSD and Linux deployment practices what we have learned at running large social games.

• Introducing Automating master failover tool

Like many other web services, DeNA uses MySQL replications (single master and multiple slaves), not using Heartbeat+DRBD because we want to utilize all database servers. But we also want to automate master failover with small enough downtime, without introducing consistency problems. This is an important requirement for social game providers like us who need to run large web services for both paying and non-paying customers. But automating master failover is not trivial. Even though you identify the latest slave, other slaves might have not received all relay logs, which will cause consistency problems. How do you make them in sync? I’ll talk about how we established automated MySQL master failover solutions and introduce our automated failover tools.