KSYNC

This sections covers how to perform a genesis-sync up to live height and how to state-sync to historical heights for Cronos Mainnet with KSYNC. In summary KSYNC is a tool developed by KYVE which is capable of syncing blocks and state-sync snapshots from the decentralized KYVE data lake directly into Cosmos blockchain nodes. For Cronos, KYVE has validated all historical blocks and state-sync snapshots (in a 10,000 interval) in a decentralized way and permanently archived them to Arweave, a decentralized storage solution. KSYNC can then pull down this verified data and apply them against the Cronos app, you can find full documentation on the tool here.

Note

Set environmental variables:

PATH="$PATH: <tools folder>"

e.g. PATH="$PATH: /Users/localuser/Cronos/bin"

Installation

You can install KSYNC with the following command, ensure that you have go1.21 installed:

go install github.com/KYVENetwork/ksync/cmd/ksync@latest

To verify the installation simply run ksync version. To build from source visit the repository on GitHub.

Sync Cronos from genesis

To sync Cronos from genesis up to live height install the binary used for genesis from here.

After the installation, init the config:

./cronosd init <your-moniker> --chain-id cronosmainnet_25-1

Download the genesis:

wget -O ~/.cronos/config/genesis.json https://raw.githubusercontent.com/crypto-org-chain/cronos-mainnet/master/cronosmainnet_25-1/genesis.json

Now that Cronos is properly set up you can start the genesis sync:

ksync block-sync --binary="/path/to/cronosd" --source="cronos"

This will run until live height has been reached, you can check the latest height which KYVE has validated and archived here.

Note that you can also configure Cosmovisor which contains all the upgrade binaries. With Cosmosvisor, you do not need to manually switch to a different version every time Cronos reaches an upgrade point. It is recommended to pair this with a systemd service file, refer to the template below:

[Unit]
Description=KSYNC deamon supervising the ksync sync process
After=network-online.target

[Service]
User=$USER
WorkingDirectory=$HOME
ExecStart=$HOME/ksync block-sync --binary="/path/to/cosmovisor" --source=cronos -y
Restart=always
RestartSec=10s
LimitNOFILE=infinity
Environment="DAEMON_NAME=cronosd"
Environment="DAEMON_HOME=$HOME/.cronos"
Environment="DAEMON_ALLOW_DOWNLOAD_BINARIES=false"
Environment="DAEMON_RESTART_AFTER_UPGRADE=false"
Environment="DAEMON_LOG_BUFFER_SIZE=512"
Environment="UNSAFE_SKIP_BACKUP=true"

[Install]
WantedBy=multi-user.target

Remember to replace $USER with your actual username.

Apply historical state-sync snapshots

The "normal" state-sync only supports syncing to live height, however KYVE has validated and archived all state-sync snapshots from genesis with a 10,000 block interval therefore historical state-sync is possible with KSYNC. Note that the archival process is still ongoing and live height has not been reached yet, check the progress here. To install Cronos, follow the same process as in the genesis sync part before. However, you will need to use a different binary version. You can find all upgrades with the relevant upgrade heights here.

To perform the state-sync execute the following command:

ksync state-sync --binary="/path/to/cronosd" --source="cronos" --target-height=$HEIGHT

If there is no state-sync snapshot available for your requested $HEIGHT, KSYNC will automatically propose the nearest snapshot the chosen height.

Sync to any historical height with height-sync

The features of historical state-sync and block-sync can now be combined to sync to any historical block height by using the combination of the two. KSYNC will state-sync to the nearest snapshot before your specified target height and sync the remaining blocks using block-sync. With this process, checking the state at a certain height is greatly improved because now you don't need to sync all the way from genesis to inspect the state of an historical block height.

To perform the height-sync execute the following command:

ksync height-sync --binary="/path/to/cronosd" --source="cronos" --target-height=$HEIGHT