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 minimizing 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.

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.

#Testnet state-sync

Snapshot are operated on rpc1 and rpc2

WARNING: This documentation assumes you have followed all previous instructions

The state-sync configuration (in app.toml) is as follows (no need to update it):

# 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 = 1000

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

Set SNAP_RPC1 and SNAP_RPC2 variable

SNAP_RPC1="https://rpc-archive-testnet.empe.io:443"
SNAP_RPC2="https://rpc-archive-testnet.empe.io: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=$(curl -s https://rpc-archive-testnet.empe.io:443/block | jq -r .result.block.header.height); \
BLOCK_HEIGHT=$((LATEST_HEIGHT - 1000)); \
TRUST_HASH=$(curl -s "https://rpc-archive-testnet.empe.io:443/block?height=$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:
# 29604 28604 2BB3A74046C625CB67D477550D99F2439D48191FD0E840FA42A324B0629A612A

Stop cosmovisor service

sudo systemctl stop cosmovisor

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

sed -i.bak -E "s|^(enable[[:space:]]+=[[:space:]]+).*$|\1true| ; \
s|^(rpc_servers[[:space:]]+=[[:space:]]+).*$|\1\"$SNAP_RPC1,$SNAP_RPC2\"| ; \
s|^(trust_height[[:space:]]+=[[:space:]]+).*$|\1$BLOCK_HEIGHT| ; \
s|^(trust_hash[[:space:]]+=[[:space:]]+).*$|\1\"$TRUST_HASH\"|" $HOME/.empe-chain/config/config.toml

Reset the node database

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` before 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.

emped tendermint unsafe-reset-all --home $HOME/.empe-chain

Restart the node and check the logs

sudo systemctl restart cosmovisor && journalctl -u cosmovisor -f