title
Centrality Test Harness

Perses

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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

Clone the Centrality test harness repo
In the project root, run the file install.sh to setup perses
Open terminal in the same project root path, execute perses -h you should see the following output

Usage: perses [options] [command]

Test harness for Centrality blockchain

Options:
  -v, --version   output the version number
  -h, --help      display help for command

Commands:
  send [options]  send multiple Generic-Asset transactions to blockchain
  blockchain      Manage blockchain network on local
  netem           Manage containers' networking emulations using linux tc core
  monitor         Metrics collections and monitoring setup for localhost
  help [command]  display help for command

Setup a local blockchain network with Perses

$ perses blockchain init -h                                          
Usage: perses blockchain init [options]

Initialise blockchain network on local

Options:
  --image <image>                  The centrality blockchain image to run (default: "cennznet/cennznet:1.0.1")
  --genesis <genesis>              The genesis block file name for this blockchain (default: "cennznet_dev")
  --validators <validators>        Number of initialised validators for this blockchain (default: "5")
  --log <log>                      Log level permodule (default: "info")
  -net, --networking <networking>  Select network condition mode: default | partition
  -h, --help                       display help for command

Run

perses blockchain -net default

Will be the same as

perses blockchain 
        --image cennznet/cennznet:1.0.1 \
        --genesis cennznet_dev \
        --validators 5 \
        --log info \
        --networking default

Which initialized a cennznet blockchain with 5 validators, using the genesis json file name cennznet_dev located at /chain-spec folder.

Partitioning network mode

Default networking will connect all validators to a default blockchain virtual network.

If the -net flag was set to partition, the blockchain will thereafter need at least --validator set to 10 and then it will create 2 separate virtuak networks called blockchain-1 and blockchain-2.

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

Teardown local blockchain

Run

perses blockchain teardown --image cennznet/cennznet:1.0.1

Will do the following tasks:

Stop and remove all running containers matches the image ancestor
Delete the local data storage node_data folder
Remove all blockchain virtual network

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

perses monitor init

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 10.10.10.1 and 10.10.10.2 respectively

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

admin/admin
Configure datasource

http://localhost:3000/datasources

Save & test
Import dashboard

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

Test harness dashboard should show up
Run command perses send and watch the monitor dashboard