Fetch Node State-Sync

Chain ID: fetchhub-4 | Current Node Version: v0.11.3

State-sync does not take care of the wasm folder on Fetch, so you need to preserve your own current wasm folder, or follow the instruction to download our wasm folder. It is best to just use our Fetch snapshot service since it is more reliable. However, read on if you insist on using state-sync.

Our State-Sync Server Setup

Our app.toml settings related to state-sync is as follows. This is for you information only. You do not need to follow the same setup on your node.

# Prune Type
pruning = "custom"

# Prune Strategy
pruning-keep-every = 2000

# State-Sync Snapshot Strategy
snapshot-interval = 2000
snapshot-keep-recent = 5

Our state-sync RPC server for Fetch is:

https://fetch-rpc.polkachu.com:443

Instruction

We assume that you use Cosmovisor to manage your node. If you do not use Cosmovisor, you will need to customize the following instruction slightly.

Create a reusable shell script such as state_sync.sh with the following code. The code will fetch important state-sync information (such as block height and trust hash) from our server and update your config.toml file accordingly.

#!/bin/bash

SNAP_RPC="https://fetch-rpc.polkachu.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)

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/.fetchd/config/config.toml

Grant user the privilege to execute script and then run the script:

chmod 700 state_sync.sh
./state_sync.sh

Stop the node:

sudo service fetch stop

Reset the node:

# On some tendermint chains
fetchd unsafe-reset-all

# On other tendermint chains
fetchd tendermint unsafe-reset-all --home $HOME/.fetchd --keep-addr-book
The above unsafe-reset-all command does not reset your wasm folder. Now it is time to double-check that you indeed have a wasm folder with content under the .fetchd folder. If so, you can proceed to restart your node right away. If not, you can download our wasm folder. Notice that we have taken out the cache sub-folder to ensure the wasm folder is compatible for all CPUs.
# Remove the empty wasm folder if you have an empty one
rm -r ~/.fetchd/wasm

# Get our wasm folder
wget -O fetch_wasmonly.tar.lz4 https://snapshots.polkachu.com/wasm/fetch/fetch_wasmonly.tar.lz4 --inet4-only

# Extract the wasm folder into the right place
lz4 -c -d fetch_wasmonly.tar.lz4  | tar -x -C $HOME/.fetchd

# Clean up
rm fetch_wasmonly.tar.lz4

Restart the node:

sudo service fetch start

If everything goes well, your node should start syncing within 10 minutes.

ALTERNATIVE ROUTE: We also have Fetch Snapshot Service to help you bootstrap a node.

Trouble-Shooting

I am not able to connect with the state-sync server

First, visit our state-sync server landing page to ensure it is not down.

Second, add Polkachu's state-sync server as your peer. You can find Polkachu's peer info here.

I am able to connect, but immediately get AppHash errors

Make sure that you use the latest version of the chain node when you state-sync.

Other questions?

State-sync can be flaky at times. Join our Discord Server if you have any issues. Happy State-Syncing!