Basic Concepts

Masters

A JournalNode consists of two processes: Alluxio Master that processes user requests and manages metadata of the Journal storage system and Alluxio Job Master that schedules file system operations.

Workers

Manages local resources (such as memory, SDD, and HDD) that can be configured by users and performs data operations on underlying storage.

Client

The Alluxio Client supports Java API, Shell, and HTTP REST API.

• Java API

  Provides an application interface for the Alluxio. This guide describes how to use the Java API to develop Alluxio client.

• Shell

  Provides shell commands to perform operations on the Alluxio.

• HTTP REST API

  Provides other APIs except Shell and Java APIs. You can use these APIs to query information. For details, see Alluxio API.

Namespace

Transparent naming mechanism: ensures that the namespaces of Alluxio and underlying storage systems are the same.

Unified namespace: Alluxio provides a mounting API, which can be used to access data in multiple data sources in Alluxio.