Orchestrator Agent

orchestrator-agent

MySQL topology agent (daemon)

**orchestrator-agent** is a sub-project of [orchestrator](https://github.com/github/orchestrator). It is a service that runs on MySQL hosts and communicates with *orchestrator*.

**orchestrator-agent** is capable of proving operating system, file system and LVM information to *orchestrator*, as well as invoke certain commands and scripts.

The primary drive for developing **orchestrator-agent** was [Outbrain](https://github.com/outbrain)'s need for a controlled seeding mechanism, where MySQL instances would duplicate onto new/corrupt installations. As such, **orchestrator-agent**'s functionality is tightly coupled with the backup/seed mechanisms used by Outbrain, as described following. Though easily extendible, **orchestrator-agent** was not developed with a general purpose backup/restore/orchestration capabilities in mind.

Whether or not **orchestrator-agent** is useful to you depends on your needs.

Generic functionality offered by **orchestrator-agent**:

• Detection of the MySQL service, starting and stopping (start/stop/status commands provided via configuration)
• Detection of MySQL port, data directory (assumes configuration is /etc/my.cnf)
• Calculation of disk usage on data directory mount point
• Tailing the error log file
• Discovery (the mere existence of the orchestrator-agent service on a host may suggest the existence or need of existence of a MySQL service)

Specialized functionality offered by **orchestrator-agent**:

• Detection of LVM snapshots on MySQL host (snapshots that are MySQL specific)
• Creation of new snapshots
• Mounting/umounting of LVM snapshots
• Detection of DC-local and DC-agnostic snapshots available for a given cluster
• Transmitting/receiving seed data

The Outbrain seed method

The following does not discuss hard-backups where binary/logical data is written to an external/remote disk or a tape.

At Outbrain we use LVM snapshots. Each