State-Sync snapshots allow other nodes to rapidly join the network without replaying historical blocks, instead downloading and applying a snapshot of the application state at a given height.

Step by step gude how to configure Cosmic-Horizon node for work as State-Sync RPC server

# set variables
CHAIN_HOME=$HOME/.coho
CHAIN_SERVICE=cohod

# make your node discoverable from public network
laddr="tcp://0.0.0.0:26657"
sed -i.bak -e "s/^laddr *=.*/laddr = \"$laddr\"/" $CHAIN_HOME/config/config.toml

# configure pruning to custom value
# pruning = custom
# pruning-keep-recent = 100
# pruning-keep-every = 1000
# pruning-interval = 10
sed -i 's/pruning = "default"/pruning = "custom"/g' $CHAIN_HOME/config/app.toml
sed -i 's/pruning-keep-recent = "0"/pruning-keep-recent = "100"/g' $CHAIN_HOME/config/app.toml
sed -i 's/pruning-keep-every = "0"/pruning-keep-every = "1000"/g' $CHAIN_HOME/config/app.toml
sed -i 's/pruning-interval = "0"/pruning-interval = "10"/g' $CHAIN_HOME/config/app.toml

# set snapshot-interval
sed -i 's/snapshot-interval = 0/snapshot-interval = 2000/g' $CHAIN_HOME/config/app.toml

# restart node service
sudo systemctl restart $CHAIN_SERVICE

# check logs
sudo journalctl -u $CHAIN_SERVICE -f

State sync rapidly bootstraps a new node by discovering, fetching, and restoring a state machine snapshot from peers instead of fetching and replaying historical blocks. Requires some peers in the network to take and serve state machine snapshots.

Step by step gude how to bootstrap Cosmic-Horizon darkmatter-1 testnet chain

# set variables
CHAIN_HOME=$HOME/.coho
CHAIN_SERVICE=cohod
CHAIN_BINARY=cohod

# set rpc endpoints and peers
SNAPSHOT_RPC1="http://62.171.147.117:26657"
SNAPSHOT_RPC2="http://62.171.152.201:26657"
PEER1="c3e5f8aecac83085fcde58b2f065e53516046d96@62.171.147.117:26656"
PEER2="6a1dfc3489df0f69c6cea0ddfc6c5975bc71f236@62.171.152.201:26656"

# stop the chain service and perform reset
sudo systemctl stop $CHAIN_SERVICE && $CHAIN_BINARY unsafe-reset-all

# set state sync config variables
LATEST_HEIGHT=$(curl -s $SNAPSHOT_RPC1/block | jq -r .result.block.header.height)
BLOCK_HEIGHT=$((LATEST_HEIGHT - 2000))
TRUST_HASH=$(curl -s "$SNAPSHOT_RPC1/block?height=$BLOCK_HEIGHT" | jq -r .result.block_id.hash)

# check
echo $LATEST_HEIGHT $BLOCK_HEIGHT $TRUST_HASH

# set peers
peers="$PEER1,$PEER2"
sed -i.bak -e "s/^persistent_peers *=.*/persistent_peers = \"$peers\"/" $CHAIN_HOME/config/config.toml

# write config to config.toml (onde command)
sed -i.bak -E "s|^(enable[[:space:]]+=[[:space:]]+).*$|\1true| ; \
s|^(rpc_servers[[:space:]]+=[[:space:]]+).*$|\1\"$SNAPSHOT_RPC1,$SNAPSHOT_RPC2\"| ; \
s|^(trust_height[[:space:]]+=[[:space:]]+).*$|\1$BLOCK_HEIGHT| ; \
s|^(trust_hash[[:space:]]+=[[:space:]]+).*$|\1\"$TRUST_HASH\"| ; \
s|^(seeds[[:space:]]+=[[:space:]]+).*$|\1\"\"|" $CHAIN_HOME/config/config.toml

# start the service
sudo systemctl start $CHAIN_SERVICE

# check a logs
sudo journalctl -u $CHAIN_SERVICE -f