Facebook is committing to the open source community its LogDevice distributed data store for sequential data.
LogDevice was originally developed and currently deployed within Facebook for a variety of workloads, including event streaming, replication pipelines, transaction logs, and deferred work journals. LogDevice comes with a command-line administration tool called LDShell.
https://code.fb.com/core-data/open-sourcing-logdevice-a-distributed-data-store-for-sequential-data/