LS4, a Large-Scale Simple Storage System

LS4 is a distributed storage system that can store large data like photos, music or movies.

[Scalability] Grows storage capacity and I/O throughput dynamically without any modification of applications. [Availability] Prevents whole system falt from partial hardware crashes by failing-over within very small downtime. [Versioning] Takes back old data by creation time or version name of the stored objects. [Continuous snapshot] Supported based on time-based versioning. [Geo-redundancy] Supports replication of objects across multiple datacenters. [Direct data transfer] Reduces local network traffic and load of front-end servers by cooperating with proxy servers. [Traffic offloading] Enhances performance of data servers by offloading traffics to native web servers.

Data model

LS4 stores a set of objects identified by a key. Each object consists with data and attributes, and can have multiple versions.

key                        object
                  data                  attributes
           +-----------------+---------------------------------+       ---+
"image1" =>  |  "HTJ PNG ..."  |  { type:png, model:NEX-5 }      |--+       | each object can
           +-----------------+---------------------------------+  |--+    | have multiple
             +-----------------+----------------------------------+  |    | versoins
                +----------------+-----------------------------------+    |
                                                                       ---+
           +-----------------+---------------------------------+
key    =>  |  bytes .......  |  { key:value, key:value, ... }  |--+
           +-----------------+---------------------------------+  |--+
             +-----------------+----------------------------------+  |
                +----------------+-----------------------------------+

...    =>  ...

For more details, see LS4 Documents.

Quick Start

$ gem install ls4
$ ls4-standalone -s ./data -h 18080 &

$ curl -X POST -d 'data=value1&attrs={"test":"attr"}' http://localhost:18080/data/key1

$ curl -X GET http://localhost:18080/data/key1
value1

$ curl -X GET http://localhost:18080/attrs/key1
{"test":"attr"}

Project web site: http://ls4.sourceforge.net/
Documents: http://ls4.sourceforge.net/doc/
Documents (Japanese): http://ls4.sourceforge.net/doc/ja/
Source repository: http://github.com/ls4
Author: FURUHASHI Sadayuki
License: AGPL