High-Load Storage of Users’ Actions with ScyllaDB and HDD

The presentation gives a brief overview of the high-load service that stores users' actions using HDDs. The given service is able to serve up to 240k writes per second in less than 2ms 95 percentile with just a few ScyllaDB nodes packed with HDDs. Hardware setup, specification for cluster HDD, live load numbers and latencies achieved are given. The problems we encountered with HDD setup are described along with the possible solutions to them.