Checkpoints can build a physical snapshot of the database to another file system directory, with files are hard linked to the source as much as possible.

Function for streaming updates, and catching up

Through most systems distribute updates to replicas as an independent component, RocksDB also provides some APIs for doing it.

A replication system typically wants to annotate each Put with some arbitrary metadata. This metadata may be used to detect loops in the replication pipeline. It can also be used to timestamp and sequence transactions. For this purpose, RocksDB supports an API called that an application may use to annotate each Put with metadata. This metadata is stored only in the transaction log and is not stored in the data files. The metadata inserted via PutLogData can be retrieved via the GetUpdatesSince API.