Data Storage

Event store vs. metadata store

Seq internally uses two distinct storage subsystems:

• The metadata store, usually shortened to metastore, contains configuration data such as users, signals, dashboards, and so on
• The event store contains the application log data that is searchable in the Seq UI.

The two storage subsystems may use different technologies depending on how Seq is configured.

The Metastore

Seq's metastore is a document-oriented data layer that supports various backing storage technologies:

• Microsoft SQL Server
• PostgreSQL
• Native (embedded storage in the Documents/ subfolder under Seq's local storage root). This is the default option for Seq installs and doesn't rely on any external database or storage technologies.

Data in the metastore is included in Seq's automatic nightly backups.

The Event Store

Seq relies heavily on the functionality of its own internal event store for log storage and querying. The event store is built by Datalust in the Rust programming language, specifically for Seq.

The event store persists data in the Stream/ directory under Seq's local storage root.

You can learn more about the design of Seq's event store on the Seq blog.