Expand description
start subcommand - entry point for starting a zebra node
§Application Structure
A zebra node consists of the following major services and tasks:
Peers:
- Peer Connection Pool Service
- primary external interface for outbound requests from this node to remote peers
- accepts requests from services and tasks in this node, and sends them to remote peers
- Peer Discovery Service
- maintains a list of peer addresses, and connection priority metadata
- discovers new peer addresses from existing peer connections
- initiates new outbound peer connections in response to demand from tasks within this node
- Peer Cache Service
- Reads previous peer cache on startup, and adds it to the configured DNS seed peers
- Periodically updates the peer cache on disk from the latest address book state
Blocks & Mempool Transactions:
- Consensus Service
- handles all validation logic for the node
- verifies blocks using zebra-chain, then stores verified blocks in zebra-state
- verifies mempool and block transactions using zebra-chain and zebra-script, and returns verified mempool transactions for mempool storage
- Inbound Service
- primary external interface for inbound peer requests to this node
- handles requests from peers for network data, chain data, and mempool transactions
- spawns download and verify tasks for each gossiped block
- sends gossiped transactions to the mempool service
Blocks:
- Sync Task
- runs in the background and continuously queries the network for new blocks to be verified and added to the local state
- spawns download and verify tasks for each crawled block
- State Service
- contextually verifies blocks
- handles in-memory storage of multiple non-finalized chains
- handles permanent storage of the best finalized chain
- Old State Version Cleanup Task
- deletes outdated state versions
- Block Gossip Task
- runs in the background and continuously queries the state for newly committed blocks to be gossiped to peers
- Progress Task
- logs progress towards the chain tip
Shielded Scanning:
- Shielded Scanner Task
- if the user has configured Zebra with their shielded viewing keys, scans new and existing blocks for transactions that use those keys
Block Mining:
- Internal Miner Task
- if the user has configured Zebra to mine blocks, spawns tasks to generate new blocks, and submits them for verification. This automatically shares these new blocks with peers.
Mempool Transactions:
- Mempool Service
- activates when the syncer is near the chain tip
- spawns download and verify tasks for each crawled or gossiped transaction
- handles in-memory storage of unmined transactions
- Queue Checker Task
- runs in the background, polling the mempool to store newly verified transactions
- Transaction Gossip Task
- runs in the background and gossips newly added mempool transactions to peers
Remote Procedure Calls:
- JSON-RPC Service
- answers RPC client requests using the State Service and Mempool Service
- submits client transactions to the node’s mempool
Zebra also has diagnostic support:
Some of the diagnostic features are optional, and need to be enabled at compile-time.
Structs§
- Start the application (default command)