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State sync

composable

{% hint style='info' %} State Sync allows a new node to join the network by fetching a snapshot of the application state at a recent height instead of fetching and replaying all historical blocks. Since the application state is generally much smaller than the blocks, and restoring it is much faster than replaying blocks, this can reduce the time to sync with the network from days to minutes. {% endhint %}

Instructions​

Stop the service and reset the data​

sudo systemctl stop lambdavm
cp $HOME/.lambdavm/data/priv_validator_state.json $HOME/.lambdavm/priv_validator_state.json.backup
lambdavm tendermint unsafe-reset-all --keep-addr-book --home $HOME/.lambdavm

Get and configure the state sync information​

SNAP_RPC=https://rpc.lambda.nomadvalidator.com:443 && \
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) && \
echo $LATEST_HEIGHT $BLOCK_HEIGHT $TRUST_HASH

peers="234b319119af66069cc44323a622dd40748f72e1@rpc.lambda.nomadvalidator.com:26656"
sed -i.bak -e  "s/^persistent_peers *=.*/persistent_peers = \"$peers\"/" $HOME/.lambdavm/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\"| ; \
s|^(seeds[[:space:]]+=[[:space:]]+).*$|\1\"\"|" $HOME/.lambdavm/config/config.toml

mv $HOME/.lambdavm/priv_validator_state.json.backup $HOME/.lambdavm/data/priv_validator_state.json

Restart the service and check the log​

sudo systemctl start lambdavm && sudo journalctl -u lambdavm -f --no-hostname -o cat