Run a Validator on the Spend Hub testnet

::: tip Information on how to join the testnet (genesis.json file and seeds) is held in our launch repo. :::

Before setting up your validator node, make sure you've already gone through the Full Node Setup 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 voting. A validator's stake is slashed if they become unavailable or sign blocks at the same height. Please read about Sentry Node Architecture to protect your node from DDOS attacks and to ensure high-availability.

::: danger Warning If you want to become a validator for the Hub's testnet, you should research security. :::

You may want to skip the next section if you have already set up a full-node.

Create Your Validator

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

spend tendermint show-validator

To create your validator, just use the following command:

::: warning Don't use more ustaking than you have! :::

spendcli tx staking create-validator \
  --amount=1000000ustaking \
  --pubkey=$(spend 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="1" \
  --gas="auto" \
  --gas-prices="0.025ustaking" \
  --from=<key_name>

::: tip 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. :::

::: tip 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 1 means your validator will never have a self-delegation lower than 1staking, or 1000000ustaking :::

You can confirm that you are in the validator set by using a third party explorer.

Participate in Genesis as a Validator

::: warning The genesis ceremony for the Spend Hub testnet is closed. Please skip to the next section. :::

If you want to participate in genesis as a validator, you need to justify that you have some stake at genesis, create one (or multiple) transactions to bond this stake to your validator address, and include this transaction in the genesis file.

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

spend tendermint show-validator

Next, craft your spend gentx command.

::: tip A gentx is a JSON file carrying a self-delegation. All genesis transactions are collected by a genesis coordinator and validated against an initial genesis.json. :::

::: warning Note Don't use more ustaking than you have! :::

spend gentx \
  --amount <amount_of_delegation_ustaking> \
  --commission-rate <commission_rate> \
  --commission-max-rate <commission_max_rate> \
  --commission-max-change-rate <commission_max_change_rate> \
  --pubkey <consensus_pubkey> \
  --name <key_name>

::: tip 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. :::

You can then submit your gentx on the launch repository. These gentx will be used to form the final genesis file.

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 specifies which validator you are editing. If you choose to not include certain flags, 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 with 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.

spendcli tx staking edit-validator
  --moniker="choose a moniker" \
  --website="https://cosmos.network" \
  --identity=6A0D65E29A4CBC8E \
  --details="To infinity and beyond!" \
  --chain-id=<chain_id> \
  --gas="auto" \
  --gas-prices="0.025ustaking" \
  --from=<key_name> \
  --commission-rate="0.10"

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

  • 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:

spendcli 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:

spendcli 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).

spendcli 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:

spendcli query tendermint-validator-set | grep "$(spend tendermint show-validator)"

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

::: warning Note To be in the validator set, you need to have more total voting power than the 100th validator. :::

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 spend. The node will shutdown with a zero exit code at that given height after committing the block.

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 500 of the last 10000 blocks, or if they double sign.

If you got jailed for downtime, you can get your voting power back to your validator. First, if spend is not running, start it up again:

spend start

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

Lastly, check your validator again to see if your voting power is back.

spendcli 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 spend crashes because of too many open files

The default number of files Linux can open (per-process) is 1024. spend 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 restart the process with spend start. If you are using systemd or another process manager to launch spend this may require some configuration at that level. A sample systemd file to fix this issue is below:

# /etc/systemd/system/spend.service
[Unit]
Description=Spend Spend Node
After=network.target

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

[Install]
WantedBy=multi-user.target