Case Study: Mail.Ru achieves high-load action storage with ScyllaDB

Russia’s Largest Email Service Stores User Actions at High-Load with ScyllaDB on Hard Disk Drives

Mail.Ru, one of Russia’s largest email and internet services, needed a way to store high-volume user action history at scale. Its homegrown system was hard to maintain, lacked key database features like secondary indexes and tunable replication, and struggled to scale efficiently as traffic grew. ScyllaDB was selected as the storage solution for this high-load action history workload.

Mail.Ru implemented ScyllaDB on bare metal across two datacenters, using 9 nodes total and even running on hard disk drives to reduce costs. With ScyllaDB, the company achieved 240,000 writes per second with 95% latency of about 1.5 ms and 99.9% latency of about 22 ms, while reads were served with predictable performance. Mail.Ru also reported saving at least $150,000 in capital expenses per petabyte compared with an SSD setup, showing the measurable cost impact of using ScyllaDB.

Mail.Ru

Kirill Alexseev

Software Engineering Technical Lead