State Sync

Pre-requisites

• Install Point Node
• Run Point Node

State Syncing a Node

Once a few nodes in a network have taken state sync snapshots, new nodes can join the network using state sync. To do this, the node should first be configured as usual, and the following pieces of information must be obtained for light client verification:

• Two available RPC servers (at least)
• Trusted height
• Block ID hash of trusted height

The trusted hash must be obtained from a trusted source (eg. a block explorer), but the RPC servers do not need to be trusted. Tendermint will use the hash to obtain trusted app hashes from the blockchain in order to verify restored application snapshots. The app hash and corresponding height are the only pieces of information that can be trusted when restoring snapshots. Everything else can be forged by adversaries.

Set the node name

moniker="NODE_NAME"

Use commands below

For Mainnet setup

SNAP_RPC1="http://rpc-mainnet-1.point.space:26659"
SNAP_RPC="http://rpc-mainnet-1.point.space:26659"
CHAIN_ID="point_10687-1"
PEER="8673c1f04c29c464189e8bf29e51fb0b38da2f19@rpc-mainnet-1.point.space:26656"
wget -O $HOME/genesis.json https://raw.githubusercontent.com/pointnetwork/point-chain-config/main/mainnet-1/genesis.json

For Uranus Testnet setup

SNAP_RPC1="https://xnet-uranus-1.point.space:26657"
SNAP_RPC="https://xnet-uranus-1.point.space:26657"
CHAIN_ID="point_10731-1"
PEER="9f68144936ca8131c29ce15b690fd92e12388187@xnet-uranus-1.point.space:26656"
wget -O $HOME/genesis.json https://raw.githubusercontent.com/pointnetwork/point-chain-config/main/testnet-xNet-Uranus-1/genesis.json

Common part

Reset the node

pointd tendermint unsafe-reset-all --home $HOME/.pointd

Change config files (set the node name, add persistent peers, set indexer = "null")

sed -i -e "s%^moniker *=.*%moniker = \"$moniker\"%; " $HOME/.pointd/config/config.toml
sed -i -e "s%^indexer *=.*%indexer = \"null\"%; " $HOME/.pointd/config/config.toml
sed -i -e "s%^persistent_peers *=.*%persistent_peers = \"$PEER\"%; " $HOME/.pointd/config/config.toml

Set the variables for start from snapshot

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

echo $LATEST_HEIGHT $BLOCK_HEIGHT $TRUST_HASH

Output example (numbers will be different):

911348 909348 7A2C851A4ECCF5C6728411F53EAACD0D6E6A0C18BD77DB2E9AD91E78465930FC

If output is OK do next

sed -i.bak -E "s|^(enable[[:space:]]+=[[:space:]]+).*$|\1true| ; \

s|^(rpc_servers[[:space:]]+=[[:space:]]+).*$|\1\"$SNAP_RPC,$SNAP_RPC1\"| ; \

s|^(trust_height[[:space:]]+=[[:space:]]+).*$|\1$BLOCK_HEIGHT| ; \

s|^(trust_hash[[:space:]]+=[[:space:]]+).*$|\1\"$TRUST_HASH\"| ; \

s|^(seeds[[:space:]]+=[[:space:]]+).*$|\1\"\"|" ~/.pointd/config/config.toml

Now you just need to run the node.

pointd start

Check logs

When the node is started it will then attempt to find a state sync snapshot in the network, and restore it:

Started node                   module=main nodeInfo="..."
Discovering snapshots for 20s
Discovered new snapshot        height=3000 format=1 hash=0F14A473
Discovered new snapshot        height=2000 format=1 hash=C6209AF7
Offering snapshot to ABCI app  height=3000 format=1 hash=0F14A473
Snapshot accepted, restoring   height=3000 format=1 hash=0F14A473
Fetching snapshot chunk        height=3000 format=1 chunk=0 total=3
Fetching snapshot chunk        height=3000 format=1 chunk=1 total=3
Fetching snapshot chunk        height=3000 format=1 chunk=2 total=3
Applied snapshot chunk         height=3000 format=1 chunk=0 total=3
Applied snapshot chunk         height=3000 format=1 chunk=1 total=3
Applied snapshot chunk         height=3000 format=1 chunk=2 total=3
Verified ABCI app              height=3000 appHash=F7D66BC9
Snapshot restored              height=3000 format=1 hash=0F14A473
Executed block                 height=3001 validTxs=16 invalidTxs=0
Committed state                height=3001 txs=16 appHash=0FDBB0D5F
Executed block                 height=3002 validTxs=25 invalidTxs=0
Committed state                height=3002 txs=25 appHash=40D12E4B3

The node is now state synced, having joined the network in seconds

Use this command to switch off your State Sync mode, after node fully synced to avoid problems in future node restarts!

sed -i.bak -E "s|^(enable[[:space:]]+=[[:space:]]+).*$|\1false|" $HOME/.pointd/config/config.toml