sync-with-state-sync.md

description
Instructions for joining Juno networks with statesync

Sync with state-sync

State-sync is a module built into the Cosmos SDK to allow validators to rapidly join the network by syncing your node with a snapshot enabled RPC from a trusted block height.

This greatly reduces the time required for a validator or sentry to sync with the network from days to minutes. The limitations of this are that there is not a full transaction history, just the most recent state that the state-sync RPC has stored. An advantage of state-sync is that the database is very small in comparison to a fully synced node, therefore using state-sync to resync your node to the network can help keep running costs lower by minimising storage usage.

By syncing to the network with state-sync, a node can avoid having to go through all the upgrade procedures and can sync with the most recent binary only.

{% hint style="info" %} For nodes that are intended to serve data for dapps, explorers or any other RPC requiring full history, state-syncing to the network would not be appropriate. {% endhint %}

Mainnet state-sync

Polkachu operate and maintain a snapshot RPC for the juno-1 mainnet network.

{% hint style="info" %} This documentation assumes you have followed the instructions for Joining Mainnet and Setting up Cosmovisor. {% endhint %}

The state-sync configuration is as follows:

# snapshot-interval specifies the block interval at which local state sync snapshots are
# taken (0 to disable). Must be a multiple of pruning-keep-every.
snapshot-interval = 2000

# snapshot-keep-recent specifies the number of recent snapshots to keep and serve (0 to keep all).
snapshot-keep-recent = 10

Set SNAP_RPC variable to the polkachu snapshot RPC

SNAP_RPC="https://juno-rpc.polkachu.com:443"

Fetch the LATEST_HEIGHT from the snapshot RPC, set the state-sync BLOCK_HEIGHT and fetch the TRUST_HASH from the snapshot RPC. The BLOCK_HEIGHT to sync is determined by subtracting the snapshot-interval from the LATEST_HEIGHT.

LATEST_HEIGHT=$(curl -s $SNAP_RPC/block | jq -r .result.block.header.height); \
BLOCK_HEIGHT=$((LATEST_HEIGHT - 2000)); \
TRUST_HASH=$(curl -s "$SNAP_RPC/block?height=$BLOCK_HEIGHT" | jq -r .result.block_id.hash)

Check variables to ensure they have been set

echo $LATEST_HEIGHT $BLOCK_HEIGHT $TRUST_HASH

# output should be something similar to:
# 1002969 1000969 0B532538F74C946B82D1697704B25F2D8E12D989766B30AF5F8730A7A7A94CDB

If you have not already, set some seeds.

Set the required variables in ~/.juno/config/config.toml

sed -i.bak -E "s|^(enable[[:space:]]+=[[:space:]]+).*$|\1true| ; \
s|^(rpc_servers[[:space:]]+=[[:space:]]+).*$|\1\"$SNAP_RPC,$SNAP_RPC\"| ; \
s|^(trust_height[[:space:]]+=[[:space:]]+).*$|\1$BLOCK_HEIGHT| ; \
s|^(trust_hash[[:space:]]+=[[:space:]]+).*$|\1\"$TRUST_HASH\"|" $HOME/.juno/config/config.toml

Stop the node and reset the node database

{% hint style="danger" %} WARNING: This will erase your node database. If you are already running validator, be sure you backed up your config/priv_validator_key.json and config/node_key.json prior to running unsafe-reset-all.

It is recommended to copy data/priv_validator_state.json to a backup and restore it after unsafe-reset-all to avoid potential double signing. {% endhint %}

sudo systemctl stop cosmovisor 
junod tendermint unsafe-reset-all --home $HOME/.juno

Restart node and check logs

sudo systemctl restart cosmovisor && journalctl -fu cosmovisor -o cat