LogDevice

Note: This is an archived project and is no longer supported or updated by Facebook.

LogDevice is a scalable and fault tolerant distributed log system. While a file-system stores and serves data organized as files, a log system stores and delivers data organized as logs. The log can be viewed as a record-oriented, append-only, and trimmable file.

LogDevice is designed from the ground up to serve many types of logs with high reliability and efficiency at scale. It's also highly tunable, allowing each use case to be optimized for the right set of trade-offs in the durability-efficiency and consistency-availability space. Here are some examples of workloads supported by LogDevice:

Write-ahead logging for durability
Transaction logging in a distributed database
Event logging
Stream processing
ML training pipelines
Replicated state machines
Journals of deferred work items

For full documentation, please visit logdevice.io.

Requirements

LogDevice is only supported on Ubuntu 18.04 (Bionic Beaver). However, it should be possible to build it on any other Linux distribution without significant challenges. LogDevice relies on some c++17 features, so building LogDevice requires a compiler that supports c++17.