title: 'Centrality Test Harness'

Perses (THIS README CURRENTLY OUTDATED - MOST OF CONTENT BELOW NO LONGER WORKING)

Table of Contents

[TOC]

Overview

To exercise Centrality's blockchain behaviors under certain loads or networking conditions, we introduce Perses to effortlessly reproduce a blockchain deployment and simulate/emulate various conditions when a chain running on your localhost.

Why it named Perses ? The name came from Greek Titan God of Destruction - exactly what it means to be: breaking our blockchain in different ways

Getting started

From source code

1. Clone the Centrality test harness repo
2. Run yarn to install the package's dependencies and build
3. Write as nomal js code to use perses

From npmjs

1. Add package centrality-perses with yarn
2. Write as nomal js code to use perses

Setup a local blockchain network with Perses

The default genesis block holding following accounts as endowed and validators: Alice, Bob, Charlie, Dave, Eve, Melissa, James, Dustin, Bonnie, Christine. For Perses's blockchain commands to work, if you specified your own genesis block please make sure keep these accounts' data

    // setup blockchain
    let containers = await perses.Blockchain.init('cennznet/cennznet:1.1.0-rc1', ['Alice', 'Bob'], 'dev', undefined, undefined, 'info');

    // get docker containers count and assert
    assert.equal(2, containers.length);

    const api = await utils.getAPI('ws://localhost:9940');

    await perses.Staking.insertSessionKeys(api, controller.meta.name);

    containers = await perses.Blockchain.restartNodes(containers);

The commands initialized a cennznet blockchain with 2 validators, using the dev chain.

Partitioning network mode

    const subNetDefs = [
      new SubnetDefinition('Blockchain-1', '11.20.0.0/16', '11.20.10.0/24', '11.20.10.200'),
      new SubnetDefinition('Blockchain-2', '11.21.0.0/16', '11.21.10.0/24', '11.21.10.200'),
    ];

    // Duck typing set subnet containers
    const subnetContainers1 = [
      {
        BlockchainContainer: containers[0],
        IpV4address: '11.20.10.1',
        disconnectDefaultBridge: true,
      },
      {
        BlockchainContainer: containers[1],
        IpV4address: '11.20.10.2',
        disconnectDefaultBridge: false,
      },
    ];

    const subnetContainers2 = [
      new SubnetContainer(containers[2], '11.21.10.1'),
      new SubnetContainer(containers[3], '11.21.10.2'),
      new SubnetContainer(containers[4], '11.21.10.3'),
    ];

    await perses.Network.createSubnets(subNetDefs[0], subnetContainers1);
    await perses.Network.createSubnets(subNetDefs[1], subnetContainers2);

    await perses.Blockchain.restartNodes(containers);
    ```

After that it would connect 5 validators to each networking group forming 2 partitioned network clusters doesn't know about eachother.


## Monitoring
Perses has built in a Grafana dashboard config and Prometheus server to collect and populate the chain's status as well as its functions when running transactions on chain.

### Setup monitor servers
#### Configure Prometheus setup

In the prometheus yaml 

/prometheus/prometheus.yml

>This change is required to populate the metrics from app's server to Prometheus server

Change the target's ip with your computer/host ip

• targets: ['192.168.10.112:8080']

#### Run the servers containers

```shell=
// In /prometheus folder
docker-compose up

You should see following containers up and running on port 9090 and 3000 for prometheus and grafana servers respectively.

Both containers (prometheus and grafana) running on a virtual network with addresses 10.10.1.3 and 10.10.1.2 respectively

1. Login Grafana dashboard Url: http://localhost:3000 Grafana default credential:

   admin/admin

2. Configure datasource

   http://localhost:3000/datasources

   Save & test

3. Import dashboard

   

   Upload the dashboard.json file in <project root path>/grafana

   Test harness dashboard should show up

   

   

Network emulation

Use perses's Network functions

Examples

TBC