SoliDB

A Distributed Content-Addressable Database

Features

• Immutability
• Scalability
• Fault-tolerance
• High availability

Components

Node

Node runs as a service to manage slices of the whole data collection. A cluster is composed with several nodes.

Master

A command line tool to manage cluster.

Quickstart

Get source code

$ git clone https://github.com/vechain/solidb.git

Compile & install

Golang tool chain is required to be installed. Also, glide is required for package management.

$ cd solidb
$ glide install
$ make install

You'll get solidb command in $GOPATH/bin.

Start a node

$ solidb node

To get help for more options:

$ solidb node -h

Maintain

Create a cluster

$ solidb new path-of-master-dir

Master dir can be relative or absolute path. To specify number of redundant copies for the whole data collection, add option '—replicas n', where n must be >= 1, defaults to 2.

Enter master dir to perform further configurations.

$ cd path-of-master-dir.solidb

Add node

$ solidb add addr-of-node

Display list of nodes

$ solidb list

Remove node

Remove first node in the list.

$ solidb remove 0

Addr or ID can also be specified as argument of remove command.

Alternate node

$ solidb alter 0 --addr new-addr --weight 2

Propose config

Generate cluster config according to current draft, and send the config to all nodes.

$ solidb propose

The count of nodes in cluster should be >= replicas, or an error will be printed.

Sync command

Tell all nodes in newest config to sync slices that are allocated.

$ solidb sync

Query status of nodes

$ solidb status

This command will display status of nodes in proposed config, e.g.

a97c…0ecc	192.168.31.182:3001	3,3,2	103/103
abe0…0a10	192.168.31.182:3002	3,3,2	103/103
a121…d57e	192.168.31.182:3003	3,3,2	102/102
1617…b42f	192.168.31.182:3004	3,3,2	102/102
34a5…d372	192.168.31.182:3005	3,3,2	102/102

column 0: ID of node column 1: address of node column 3: config revisions, newest/synced/approved column 4: synced slice count/total slice count

Approve config

Once all nodes achieve 'synced' state, the 'approve' command can be sent to make newest config take effect.

$ solidb approve

Access Blobs

We call blobs for data stored in solidb. The content type of blob is not cared about.

To store a blob:

$ curl -X POST -d "hello world" http://addr-of-one-node/blobs
{"key":"256c83b297114d201b30179f3f0ef0cace9783622da5974326b436178aeef6"}

to retrive it back:

$ curl http://addr-of-one-node/blobs/256c83b297114d201b30179f3f0ef0cace9783622da5974326b436178aeef6
hello world