Database technologies
Postgres
Postgres is an open-source relational database. Applications connect to a Neki database using the Postgres wire protocol and standard Postgres clients.Neki
Neki is PlanetScale’s distributed Postgres system. It places routers in front of Postgres shards and provides query routing, topology management, failover, sharding, and online data-movement workflows.PlanetScale
PlanetScale is a managed database platform focused on reliability, scalability, and developer productivity. PlanetScale operates the infrastructure around Neki and provides the application, APIs, and workflows used to create and manage databases.PlanetScale concepts
Organization
An organization contains PlanetScale databases and the people who can access them. Organization settings control membership, billing, and access to shared resources.Database
A database is the top-level resource an application connects to. It belongs to an organization and contains one or more branches.Branch
A branch is an isolated database environment. A database has a default branch, often namedmain, and can have additional branches for development and
testing.
Production branches are intended for production workloads and use a highly
available configuration. Development branches are intended for development and
testing.
Configuration profile
A configuration profile is a set of infrastructure settings shared by one or more shards. It defines the cluster size, replica count, Postgres version, parameters, and enabled extensions. Changing a profile applies the new settings to every shard assigned to it.Cluster size
A cluster size defines the CPU, memory, and storage resources assigned to a Postgres instance. Every shard assigned to a configuration profile uses the profile’s selected cluster size.Neki concepts
Router
A router accepts Postgres connections from applications. It plans each query, uses the data topology to find its destination shards, sends work to those shards, and combines results when a query reaches more than one shard. Routers do not store durable application data and are interchangeable.Admin
The admin monitors the Postgres instances in a Neki cluster through their sidecars. It analyzes cluster health and coordinates repairs, including replica recovery and primary failover. This control-plane service is different from a database administrator or Postgres role. Its selected size establishes a capacity baseline, and PlanetScale automatically increases its memory when needed.Orchestration layer
The orchestration layer, implemented by the Neki operator, reconciles the configuration requested through PlanetScale into running routers, Admin services, shards, and Postgres instances. It coordinates rolling changes, resizing, backups, restores, and replacement instances and reports their readiness and progress. It is outside the SQL query path and does not determine data placement.Postgres instance
A Postgres instance is one Postgres server within a shard. A serving instance can be the primary or a replica.Primary
The primary is the writable Postgres instance for a shard. Each shard has one primary at a time.Replica
A replica is a Postgres instance that copies changes from the primary through Postgres physical replication. Replicas serve reads and can be promoted during failover.Read-only replica
A read-only replica is a Postgres instance that copies changes from the primary and serves reads. Neki never promotes a read-only replica to primary, and it does not count for write durability. Routing targets and node roles call itrdonly. See Read-only replicas.