Storage Guide

Storage Guide

Nexus Repository uses a binary large object (blob) storage, or blob store, to store files found in a repository. This includes metadata, hashes, and repository-generated indexes. When adding to a repository, Nexus Repository renames and obfuscates the contents to avoid naming collisions and file system constraints. Avoid modifying these files outside of the Nexus Repository.

Repositories are configured to use either a single blob store or a blob store group. Many repositories may use the same blob store. Blob store groups may use many storage locations and different storage types.

The first time Nexus Repository launches, the initial repositories are configured to use a file system blob store named default in the data directory.

Blob stores are set to: a folder in the file system, a network storage, or cloud object storage. Configure the location of blob stores with as low latency as possible for optimal performance.

Having a large number of blob stores impacts the system performance as querying, cleanup, and indexing tasks are specific to a blob store.

When adding to a repository, Nexus Repository renames and obfuscates the contents to avoid naming collisions and file system constraints. Component metadata is stored in a file along with the component.

Learn about blob store layouts in Storage Planning

Learn how to manage blob stores from the configuring blob stores topic

Storage Terminology

An object containing data (e.g., component binaries and metadata files) within a blob store.

An internal storage mechanism for the binary parts of components and their assets.

When using a group blob store, the fill policy determines to which blob store a blob is written.

A blob store that delegates operations to one of the other blob stores on its list.

When a soft-deleted blob is permanently removed from the blob store.

When a blob store is converted to a virtual grouping of one or more blob stores. Repositories using a group may store components across multiple store locations and types.

The system labels a file for deletion, but it remains in the blob store. The compact blob store task eventually deletes these files.

This feature monitors a blob store and raises an alert when the specific metric exceeds the constraint. The system reports the blob store as unhealthy when used beyond its quota limits. However, it still allows writes to the storage with a logged warning.