Introduction to HBase: Architecture, Concepts, and Common Commands

What is HBase

HBase is a distributed, column‑oriented NoSQL database built on top of the Hadoop Distributed File System (HDFS) that provides random real‑time read/write access to massive structured data.

Relationship with HDFS

HDFS supplies reliable storage, while HBase adds fast row‑key lookups and supports billions of rows with low latency.

Data Model

Tables consist of rows identified by a unique rowkey; each row contains column families, which in turn contain columns. Cells are versioned by timestamps, allowing multiple versions of the same cell.

Key Concepts

Rowkey design, column families, timestamps, cells, regions (horizontal partitions), and the role of ZooKeeper for coordination and fail‑over.

Architecture Components

HBase includes a client library, a master server that assigns regions and balances load, region servers that host regions, and ZooKeeper for service discovery.

Features

Scalable storage of petabyte‑scale data, column‑family storage, sparse rows, schema‑less design, high concurrency, and automatic version management (TTL, keep‑last‑n‑versions).

Typical Use Cases

Large‑scale data storage and near‑real‑time queries such as traffic sensor data, transaction logs, and historical records where simple rowkey lookups are sufficient.

Common HBase Shell Commands

Typical commands include status, version, list, create, describe, alter, disable, drop, put, get, scan, delete, and truncate. Example to create a table: hbase(main):001:0> create 'myTable', {NAME => 'info'} Example to insert a row:

hbase(main):002:0> put 'myTable', 'row1', 'info:name', 'Alice'

Example to retrieve data:

hbase(main):003:0> get 'myTable', 'row1'