Skip to content

Latest commit

 

History

History
48 lines (32 loc) · 1.81 KB

ARCHITECTURE.md

File metadata and controls

48 lines (32 loc) · 1.81 KB
Raw

Daemon

Backy has a daemon that is responsible to:

  1. Schedule jobs in a timely manner according to their configuration.

  2. Provide an HTTP API to allow multiple backy servers to interact with each other.

There is a (PostgreSQL) database to store metadata about backups that both the daemon, the CLI (including the sources) interact with.

CLI

The are two levels of CLI interactions:

  1. The main backy command provides administrators interaction capabilities with the backy environment on a server to retrieve status information, run backups, restore data and some maintenance tasks.

  2. Backy itself interacts with sources through a second layer of CLI commands, specific to each source. They are called by the higher level CLI as well as from the daemon. We use this layering to allow implementing sources in different languages.

The CLI ideally does not interact with the daemon directly, but by inspecting or updating the database.

Nomenclature

Words within the context of backup software are a bit muddy, specifically the meaning of "a backup". We decided to take inspiration from the git dictionary and use it the following way:

  1. A repository is - similar to git - the logical container for the user data relevant to one thing that we are backing up.

  2. A source provides the data that should be backed up. Different kinds of sources can model arbitrary data models: backy does not care whether you are backing up virtual disk images or S3 buckets.

  3. A revision specifies the state of the source at a certain point in time and corresponds to what would be colloquially called "a backup".

  4. The daemon uses a job for every repository to execute the steps necessary to perform regular backups with all surrounding management tasks like garbage collection, verification, etc.