Overview

This project is a building block that implements a simple single-node store system to use as a building block for distributed storage systems.

Check out Project Wiki for complete description; here are some of the highlights:

• Key/Value storage with optional opaque metadata (stored along with std metadata), where values can range from tiny to huge: smallest entries inlined in local database, larger offlined to disk
• Last-modified index for building Change List - based synchronization between stores
• Automatic, configurable auto-negotiated on-the-fly compression, decompression (GZIP, LZF, depending on payload size)
• Pluggable DB storage backends. Current implementations include:
  • BDB-JE based: mature, default implementation
  • LevelDB/Java based: complete (as of 1.0), no known problems, but not as extensively used.
  • Other backends are planned for things like mdb (openLDAP / lighting) and Krati: let us know if you are interested in contributing other backends!

License

Good old Apache 2

Status

StoreMate is a mature component, and 1.0 version was recently released. It is used in production systems via inclusion in ClusterMate (see below)

Unit tests exist to verify basic functioning of the single-node data store, when accessed locally (not over network).

More documentation still needed.

Sub-modules

Project is a multi-module Maven project. Sub-modules are can be grouped in following categories:

• Low-level utility libraries:
• shared: data structures and utility methods for dealing with things like compression and hash code calculation
• Single-node store implementation
• store: Backend-independent single-node data store implementation that uses a backend implementation
• Backends:
  • backend-bdb-je: Backend implementation that uses BDB-JE store (default choice)
  • backend-leveldb: Backend implementation that uses LevelDB store (new in 0.9.7)

More on design on Wiki.

Used In

• ClusterMate uses StoreMate as its per-node Storage Layer