Becoming a Validator

Overview

Running a Validator

We suggest you try out joining a public testnet first. Information on how to join the most recent testnet can be found here.

Before setting up a validator node, make sure to have completed the Joining Mainnet guide.

If you plan to use a KMS (key management system), you should go through these steps first: Using a KMS.

What is a Validator?

Validators are responsible for committing new blocks to the blockchain through an automated voting process. A validator's stake is slashed if they become unavailable or sign blocks at the same height. Because there is a chance of slashing, we suggest you read about Sentry Node Architecture to protect your node from DDOS attacks and to ensure high-availability.

If you want to become a validator for the Hub's mainnet, you should learn more about security.

The following instructions assume you have already set up a full-node and are synchonised to the latest blockheight.

Create Your Validator

Your mpvalconspub can be used to create a new validator by staking tokens. You can find your validator pubkey by running:

crossfid tendermint show-validator

To create your validator, just use the following command:

Don't use more mpx than you have!

crossfid tx staking create-validator \
  --amount=1000000000000000000mpx \
  --pubkey=$(crossfid tendermint show-validator) \
  --moniker="choose a moniker" \
  --chain-id=<chain_id> \
  --commission-rate="0.10" \
  --commission-max-rate="0.20" \
  --commission-max-change-rate="0.01" \
  --min-self-delegation="1000000" \
  --gas="auto" \
  --gas-prices="10000000000000mpx" \
  --gas-adjustment=1.5 \
  --from=<key_name>

When specifying commission parameters, the commission-max-change-rate is used to measure % point change over the commission-rate. E.g. 1% to 2% is a 100% rate increase, but only 1 percentage point.

Min-self-delegation is a stritly positive integer that represents the minimum amount of self-delegated voting power your validator must always have. A min-self-delegation of 1000000 means your validator will never have a self-delegation lower than 1 MPX

It's possible that you won't have enough MPX to be part of the active set of validators in the beginning. Users are able to delegate to inactive validators (those outside of the active set) using the XFI Console You can confirm that you are in the validator set by using a third party explorer like XFI Scan.

Edit Validator Description

You can edit your validator's public description. This info is to identify your validator, and will be relied on by delegators to decide which validators to stake to. Make sure to provide input for every flag below. If a flag is not included in the command the field will default to empty (--moniker defaults to the machine name) if the field has never been set or remain the same if it has been set in the past.

The <key_name> specifies which validator you are editing. If you choose to not include some of the flags below, remember that the --from flag must be included to identify the validator to update.

The --identity can be used as to verify identity with systems like Keybase or UPort. When using Keybase, --identity should be populated with a 16-digit string that is generated with a keybase.io account. It's a cryptographically secure method of verifying your identity across multiple online networks. The Keybase API allows us to retrieve your Keybase avatar. This is how you can add a logo to your validator profile.

crossfid tx staking edit-validator
  --moniker="choose a moniker" \
  --website="https://google.com" \
  --identity=6A0D65E29A4CBC8E \
  --details="To infinity and beyond!" \
  --chain-id=<chain_id> \
  --gas="auto" \
  --gas-prices="10000000000000mpx" \
  --gas-adjustment=1.5 \
  --from=<key_name> \
  --commission-rate="0.10"

Warning Please note that some parameters such as commission-max-rate and commission-max-change-rate cannot be changed once your validator is up and running.

Note: The commission-rate value must adhere to the following rules:

  • Must be between 0 and the validator's commission-max-rate

  • Must not exceed the validator's commission-max-change-rate which is maximum % point change rate per day. In other words, a validator can only change its commission once per day and within commission-max-change-rate bounds.

View Validator Description

View the validator's information with this command:

crossfid query staking validator <account_cosmos>

Track Validator Signing Information

In order to keep track of a validator's signatures in the past you can do so by using the signing-info command:

crossfid query slashing signing-info <validator-pubkey>\
  --chain-id=<chain_id>

Unjail Validator

When a validator is "jailed" for downtime, you must submit an Unjail transaction from the operator account in order to be able to get block proposer rewards again (depends on the zone fee distribution).

crossfid tx slashing unjail \
 --from=<key_name> \
 --chain-id=<chain_id>

Confirm Your Validator is Running

Your validator is active if the following command returns anything:

crossfid query tendermint-validator-set | grep "$(crossfid tendermint show-address)"

You should now see your validator in one of the CrossFi Chain explorers. You are looking for the bech32 encoded address in the ~/.crossfi/config/priv_validator.json file.

Halting Your Validator

When attempting to perform routine maintenance or planning for an upcoming coordinated upgrade, it can be useful to have your validator systematically and gracefully halt. You can achieve this by either setting the halt-height to the height at which you want your node to shutdown or by passing the --halt-height flag to crossfid. The node will shutdown with a zero exit code at that given height after committing the block.

Advanced configuration

You can find more advanced information about running a node or a validator on the Tendermint Core documentation.

Common Problems

Problem #1: My validator has voting_power: 0

Your validator has become jailed. Validators get jailed, i.e. get removed from the active validator set, if they do not vote on at least 500 of the last 10,000 blocks, or if they double sign.

If you got jailed for downtime, you can get your voting power back to your validator. First, if you're not using Cosmovisor and crossfid is not running, start it up again:

crossfid start

Wait for your full node to catch up to the latest block. Then, you can unjail your validator

After you have submitted the unjail transaction, check your validator again to see if your voting power is back.

crossfid status

You may notice that your voting power is less than it used to be. That's because you got slashed for downtime!

Problem #2: My crossfid crashes because of too many open files

The default number of files Linux can open (per-process) is 1024. crossfid is known to open more than 1024 files. This causes the process to crash. A quick fix is to run ulimit -n 4096 (increase the number of open files allowed) and then restarting the process with crossfid start. If you are using systemd or another process manager to launch crossfid (such as Cosmovisor) this may require some configuration at that level. A sample systemd file to fix this issue is below:

# /etc/systemd/system/crossfid.service
[Unit]
Description=CrossFi Chain Node
After=network.target

[Service]
Type=simple
User=ubuntu
WorkingDirectory=/home/ubuntu
ExecStart=/home/ubuntu/go/bin/crossfid start
Restart=on-failure
RestartSec=3
LimitNOFILE=4096

[Install]
WantedBy=multi-user.target
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