https://github.com/diennea/herddb

A JVM-embeddable Distributed Database
https://github.com/diennea/herddb

bookkeeper calcite database distributed distributed-database embeddable embeddable-dbms java replication sql zookeeper

Last synced: 6 days ago
JSON representation

A JVM-embeddable Distributed Database

• Host: GitHub
• URL: https://github.com/diennea/herddb
• Owner: diennea
• License: apache-2.0
• Created: 2016-02-25T08:01:32.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2024-11-12T19:58:21.000Z (6 months ago)
• Last Synced: 2025-04-14T13:58:26.934Z (about 1 month ago)
• Topics: bookkeeper, calcite, database, distributed, distributed-database, embeddable, embeddable-dbms, java, replication, sql, zookeeper
• Language: Java
• Homepage: https://herddb.org
• Size: 10 MB
• Stars: 318
• Watchers: 24
• Forks: 48
• Open Issues: 73
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# What is HerdDB ?

HerdDB is a **distributed Database**, data is distributed among a cluster of server **without the need of a shared storage**.

HerdDB primary language is **SQL** and clients are encouraged to use both the JDBC Driver API and the low level API.

HerdDB is **embeddable** in any Java Virtual Machine, each node will access directly to local data without the use of the network.

HerdDB replication functions are built upon **Apache ZooKeeper** and **Apache BookKeeper**.

HerdDB is internally very similar to a NoSQL database and, basically, it is a **key-value DB** with an SQL abstraction layer which enables every user to leverage existing known-how and to port existing applications.

*HerdDB has been designed for fast "writes" and for primary key read/update data access patterns.*

HerdDB supports **transactions** and "committed read" isolation level

HerdDB uses **Apache Calcite** as SQL parser and SQL Planner

## Basic concepts

Data, as in any **SQL database**, is organized in tables and tables are grouped inside **Tablespaces**.

A Tablespace is the fundamental architectural brick upon which the replication is built and some DB features are available only among tables of the same tablespace:

- transactions may span only tables of the same tablespace

- subqueries may span only tables of the same tablespace

Replication is configured at tablespace level, so for each tablespace only one server is designed to be the 'leader' (manager) at a specific point in time, then you may configure a set of 'replicas'.

The system automatically replicates data between replicas and handles server failures transparently.

## Overview

[Introducing HerdDB - Pulsar Summit 2020](https://www.youtube.com/watch?v=K7xQZ9V9Ml0) - Enrico Olivelli

[![Introducing HerdDB - Youtube link](https://img.youtube.com/vi/K7xQZ9V9Ml0/0.jpg)](https://www.youtube.com/watch?v=K7xQZ9V9Ml0)

[Other talks and deep dives](https://github.com/diennea/herddb/wiki/Talks-&-Publications)

## Getting Involved

Join the [mailing list](http://lists.herddb.org/mailman/listinfo)

## License

HerdDB is under [Apache 2 license](http://www.apache.org/licenses/LICENSE-2.0.html).