How to run a Validator node

Registering and running a validator node requires a few steps to be followed.

Create a wallet for the validator and register it on the chain as a validator by paying the registration fee.
Setup the node and wait for it to fully sync up. This node will be setup with a node wallet (not the same as validator wallet for security reasons) that will be used to sign blocks and consensus.
Register the node with the validator public key on the chain by calling setPRepNodePublicKey method.

This guide will help you set up a validator node using Docker.

Prerequisites

Install Docker (opens in a new tab)
Install Docker Engine (opens in a new tab)
Install docker-compose (opens in a new tab) as well if it is not installed with Docker by default

Get the official Docker Image: iconloop/icon2-node

System Requirements

CPU:  minimum 4core, recommend 8core +
RAM:  minimum 16GB, recommend 32GB +
DISK : minimum SSD 2.5TB, recommend SSD 3TB +
Network: minimum 1Gbps, recommend 2Gbps +

External Communications
TCP 7100: TCP port used for peer-to-peer connection between peer nodes.
TCP 9000: JSON-RPC or RESTful API port serving application requests.P-Rep must allow TCP connections to port 7100 and 9000 of an external host. ( Use 0.0.0.0/0 for a source from any network )

Creating a wallet for the validator

The first step is to create a wallet and keystore file. You can follow the instructions in this guide to create a wallet.

This wallet needs to be funded with enough ICX to be able to register as a validator, the registration fee is 2,000 ICX and you will also need a small amount of ICX to pay for the transaction fees.

Registering a validator on chain

Registering a validator node by calling the registerPrep function

Once the wallet is funded you can register as a validator node using the registerPrep (opens in a new tab) function from the JSON-RPC API.

This can be done directly from the tracker, using goloop or calling the RPC method directly.

Using the tracker

The easiest way to sign this transaction is to load up the keystore in a browser wallet (Hana Wallet (opens in a new tab)) and sign the transaction directly from the tracker by login in first with your wallet and then going to the contract page and calling the registerPrep function.

https://tracker.icon.community/contract/cx0000000000000000000000000000000000000000#contract (opens in a new tab)

Using goloop cli or preptools

Goloop CLI and the preptools are 2 command line utilities that can be used to interact with the ICON blockchain.

These can be used to sign the transaction and call the registerPrep function.

https://github.com/icon-project/goloop/blob/master/doc/goloop_cli.md#goloop-rpc-sendtx-call (opens in a new tab)

https://github.com/icon-project/preptools/blob/master/README.md#registerprep (opens in a new tab)

Using the JSON-RPC API

Calling the method from the JSON-RPC API directly requires sending a signed transaction with the following parameters:

Request

{
  "jsonrpc": "2.0",
  "id": 1234,
  "method": "icx_sendTransaction",
  "params": {
    "value": "0x6c6b935b8bbd400000",
    "data": {
      "method": "registerPRep",
      "params": {
        "name": "ABC Node",
        "country": "KOR",
        "city": "Seoul",
        "email": "abc@example.com",
        "website": "https://abc.example.com/",
        "details": "https://abc.example.com/details/",
        "p2pEndpoint": "abc.example.com:7100",
        "nodeAddress": "hxe7af5fcfd8dfc67530a01a0e403882687528dfcb"
      }
    },
    ...
  }
}

Parameters

Key	VALUE Type	Required	Description
name	T_STRING	true	P-Rep name "ABC Node"
email	T_STRING	true	P-Rep email "abc@example.com"
country	T_STRING	true	ISO 3166-1 ALPHA-3 (opens in a new tab) "KOR", "USA", "CHN"
city	T_STRING	true	"Seoul", "New York", "Paris"
website	T_STRING	true	P-Rep homepage url "https://abc.example.com (opens in a new tab)"
detailes	T_STRING	true	Url including P-Rep detail information "https://abc.example.com/details/ (opens in a new tab)"
p2pEndpoint	T_STRING	true	Network info used for connecting among P-Rep nodes "123.45.67.89:7100", "node.example.com:7100"
nodeAddress	T_STRING	False	Node Key for only consensus "hxe7af5fcfd8dfc67530a01a0e403882687528dfcb"

The following guide explains how to interact with the ICON JSON-RPC API: ICON JSON-RPC API

Node Grades

Node grades are another term for node levels.

After successfully registering as a validator node using registerPrep (opens in a new tab) the grade of the node will be set to "0x2".

There are 3 node grades, detailed below. You can also check the grade return parameter from getPrep (opens in a new tab) function from the JSON-RPC API for more info

Grade number	Usage	Description
0x2	Validator Candidate	Register your node as a candidate to become a block validator and network governance delegate
0x1	Sub-Validator	Register your node as a sub-validator for block production and validation and network governance delegate
0x0	Main Validator	Register your node as a validator for block production and validation and network governance delegate

Setting up the node

Following the instructions for creating a wallet, you will need to create a new wallet that will be used to operate the node.

Once you have the new wallet (node wallet) create a working folder in your server on a disk with enough space as detailed in the system requirements previously mentioned.

For this tutorial we will use the following folder structure:

mkdir ~/icon-node

Change to the newly created directory

cd ~/icon-node

Create inside the folder the following directories and files:

mkdir config
touch docker-compose.yml

Save the node keystore file (the node wallet) that was previously created in the config directory.

At this point your folder structure should look like this:

.
├── config
│   └── keystore.json
└── docker-compose.yml

Open docker-compose.yml in a text editor and add the following content:

version: "3"
services:
   prep:
      image: iconloop/icon2-node
      container_name: "icon2-node"
      network_mode: host
      restart: "always"
      environment:
         SERVICE: "MainNet"  # MainNet, SejongNet  ## network type
         GOLOOP_LOG_LEVEL: "debug" # trace, debug, info, warn, error, fatal, panic
         KEY_STORE_FILENAME: "keystore.json"
         KEY_PASSWORD: "INPUT_YOUR_KEY_PASSWORD"
         FASTEST_START: "true"    # It can be restored from latest Snapshot DB.

         ROLE: 3 # Validator = 3, API Endpoint = 0

      cap_add:
         - SYS_TIME

      volumes:
         - ./data:/goloop/data # mount a data volumes
         - ./config:/goloop/config # mount a config volumes ,Put your used keystore file here.
         - ./logs:/goloop/logs
      ports:
         - 9000:9000
         - 7100:7100

Run the following command to start the ICON2 node and wait for the entire ledger to locally sync up.

$ docker-compose pull && docker-compose up -d

you can monitor the process by checking the logs file that are created in the logs directory.

$ tail -f logs/booting.log


$ tail -f logs/goloop.log

The following folder structure will be created:

.
├── docker-compose.yml
├── config              # configuration files
│   └── keystore.json   # Import your keystore file

├── data                # block data
│   ├── 1
│   ├── auth.json
│   ├── cli.sock
│   ├── ee.sock
│   └── rconfig.json
├── logs                # log files
│   ├── booting.log
│   ├── health.log      # health check log
│   ├── chain.log       # goloop chain action logs
│   ├── dowload.log
│   └── dowload_error.log
│   └── goloop.log

Docker environments settings

Name	default	type	required	description
SERVICE	MainNet	str	false	Service Name - (MainNet, SejongNet)
ROLE	3	int	true	Role of running node. 0: Citizen, 3: P-Rep
CONFIG_URL		str	false
CONFIG_URL_FILE	default_configure.json	str	false
CONFIG_LOCAL_FILE	configure.json	str	false
IS_AUTOGEN_CERT	false	bool	false	Automatically generate certificates
FASTEST_START	false	bool	false	Download snapshot DB
KEY_STORE_FILENAME	keystore.json	str	true	keystore.json file name
KEY_PASSWORD		str	true	password of keystore.json file
USE_NTP_SYNC	True	bool	false	Whether to use NTP in container
NTP_SERVER		str	false	NTP Server
NTP_REFRESH_TIME		int	false	ntp refresh time
SLACK_WH_URL		str	false	slack web hook url - If a problem occurs, you can receive an alarm with a slack.
USE_HEALTH_CHECK	True	bool	false	Whether to use health check
CHECK_TIMEOUT	10	int	false	sec - TIMEOUT when calling REST API for monitoring
CHECK_PEER_STACK	6	int	false	sec - Stack value to check the peer for monitoring.
CHECK_BLOCK_STACK	10	int	false	sec - Stack value to check the block for monitoring.
CHECK_INTERVAL	10	int	false	sec - check interval for monitoring
CHECK_STACK_LIMIT	360	int	false	count - count- Restart container when stack value is reached
GOLOOP_LOG_LEVEL	debug	str	false	Log Level - (trace,debug,info,warn,error,fatal,panic
LOG_OUTPUT_TYPE	file	str	false	sec - check interval for monitoring

Registering a validator node public key

After the node is up and running, you can register the public key of the node by following the instructions in this guide.

Final steps

After completing the above steps your validator node should become an active validator on the ICON network after 48 hours of being registered.

If you need any help or assistance during the process you can reach out to the ICON community in our discord channel: ICON Discord

Debugging a local network How to register a validator node public key