Start Besu
Nodes can connect to Ethereum Mainnet and public testnets.
Use the besu
command with the required command line options to start a node.
Prerequisites
Local block data
When connecting to a network other than the network previously connected to, you must either delete the local block data or use the --data-path
option to specify a different data directory.
To delete the local block data, delete the database
directory in the besu/build/distribution/besu-<version>
directory.
Genesis configuration
Besu specifies the genesis configuration, and sets the network ID and bootnodes when connecting to Goerli, Sepolia, and Mainnet.
The Ropsten, Rinkeby, and Kiln testnets are deprecated.
When you specify --network=dev
, Besu uses the development mode genesis configuration with a fixed low difficulty. A node started with --network=dev
has an empty bootnodes list by default.
The genesis files defining the genesis configurations are in the Besu source files.
To define a genesis configuration, create a genesis file (for example, genesis.json
) and specify the file using the --genesis-file
option.
Syncing and storage
By default, Besu syncs to the current state of the blockchain using fast sync in:
- Networks specified using
--network
except for thedev
development network. - Ethereum Mainnet.
We recommend using snap sync for a faster sync, by starting Besu with --sync-mode=X_SNAP
.
By default, Besu stores data in the Forest of Tries format. We recommend using Bonsai Tries for lower storage requirements, by starting Besu with --data-storage-format=BONSAI
.
Run a node for testing
To run a node that mines blocks at a rate suitable for testing purposes:
besu --network=dev --miner-enabled --miner-coinbase=0xfe3b557e8fb62b89f4916b721be55ceb828dbd73 --rpc-http-cors-origins="all" --host-allowlist="*" --rpc-ws-enabled --rpc-http-enabled --data-path=/tmp/tmpDatdir
You can also use the following configuration file on the command line to start a node with the same options as above:
network="dev"
miner-enabled=true
miner-coinbase="0xfe3b557e8fb62b89f4916b721be55ceb828dbd73"
rpc-http-cors-origins=["all"]
host-allowlist=["*"]
rpc-ws-enabled=true
rpc-http-enabled=true
data-path="/tmp/tmpdata-path"
The following settings are a security risk in production environments:
- Enabling the HTTP JSON-RPC service (
--rpc-http-enabled
) and setting--rpc-http-host
to 0.0.0.0 exposes the RPC connection on your node to any remote connection. - Setting
--host-allowlist
to"*"
allows JSON-RPC API access from any host. - Setting
--rpc-http-cors-origins
to"all"
or"*"
allows cross-origin resource sharing (CORS) access from any domain.
Run a node on Goerli testnet
To run a node on Goerli specifying a data directory:
besu --network=goerli --data-path=<path>/<goerlidata-path>
Where <path>
and <goerlidata-path>
are the path and directory to save the Goerli chain data to.
See the guide on connecting to a testnet for more information.
Run a node on Sepolia testnet
To run a node on Sepolia specifying a data directory:
besu --network=sepolia --data-path=<path>/<sepoliadata-path>
Where <path>
and <sepoliadata-path>
are the path and directory to save the Sepolia chain data to.
See the guide on connecting to a testnet for more information.
Run a node on Ethereum Mainnet
To run a node on the Ethereum Mainnet:
besu
To run a node on Mainnet with the HTTP JSON-RPC service enabled and available for localhost only:
besu --rpc-http-enabled
See the guide on connecting to Mainnet for more information.
Confirm node is running
If you started Besu with the --rpc-http-enabled
option, use cURL to call JSON-RPC API methods to confirm the node is running.
eth_chainId
returns the chain ID of the network.curl -X POST --data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' localhost:8545
eth_syncing
returns the starting, current, and highest block.curl -X POST --data '{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":1}' localhost:8545
For example, after connecting to Mainnet,
eth_syncing
will return something similar to:{
"jsonrpc": "2.0",
"id": 1,
"result": {
"startingBlock": "0x0",
"currentBlock": "0x2d0",
"highestBlock": "0x66c0"
}
}