Start Besu
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
To define a genesis configuration, create a genesis file (for example, genesis.json
) and specify the file using the --genesis-file
option.
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.
Predefined genesis configurations for named networks are in the Besu source files.
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"
}
}
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 a private network
To run a node on your private network specifying a genesis file and data directory:
besu --genesis-file=<path>/genesis.json --data-path=<data-path> --rpc-http-enabled --bootnodes=<bootnodes>
Where <data-path>
is the path to the directory to save the chain data to. Ensure you configure a peer discovery method, such as bootnodes.
You might need to set --tx-pool-limit-by-account-percentage
to 1. The default value is suitable for Mainnet, but may cause issues on private networks.