Prototype: Scalable Server for CryptPad

This repository contains a distributed server prototype for CryptPad. This is still in progress exploratory work.

Architecture

Taxonomy

The new server architecture is composed of three types of nodes:

• Core: these nodes take care of most of the computations and internal communication handling. They are connected to the other type of servers.
• Client WebSocket: these nodes catch the different queries from the outside and forward them to the core nodes for processing.
• Storage: these nodes are responsible for accessing and serving a fraction of the (encrypted) data for CryptPad. They are also doing light computation if they can be done in place without too much pressure on them.

Topology

The core nodes are connected to both ws and storage nodes, but the latter two cannot communicate directly.

Configuration

The configuration can be done using the Config argument, which will store the graph topology of the nodes.

Using websockets for communication, this variable looks like this:

let Config = {
    infra: {
        ws: [{
            host: 'localhost',
            port: 3010
        }],
        core: [{
            host: 'localhost',
            port: 3011
        }, {
                host: 'localhost',
                port: 3012
            }],
        storage: [{
            host: 'localhost',
            port: 3014
        }]
    }
};

The above configuration describes a network comprised of 4 nodes, having one websocket client node on port 3010, 2 core servers on port 3011 and 3012 and a storage node accessible via port 3014.

In addition, launching a server requires setting the field myId with your identifier, which will be of the form type:id. For instance, in the first core node (the node listening on port 3011), it would be Config.myId = 'core:0'.

Usage

Before first use, you may want to install the dependencies with:

npm install

To spawn the server topology described in ws-config.js, run the start script:

npm run start

Alternatively, you can the new servers manually. You first need to start the core nodes with the following command.

node core/index.js

Then you can start a ws and storage nodes in any order:

node storage/index.js
node websocket/index.js

Tests

The directory tests contains some unit and integration tests scripts and files.

• interface.test.js: test the communication interface by implementing a simple ping-pong protocol that computes the time it takes to go back and forth in the network.

The aforementioned tests can be run with the following command (make sure to have installed the dependencies with npm install beforehand):

npm run tests