Types of nodes
There are 5 types of nodes on the Zilliqa network:
NOTE: Transaction types (Type I, II, III) are explained in this blog post HERE.
The shard nodes handle the Type I and Type II intra-shard transactions, and submit the co-signed micro TX-blocks to the Directory Service (DS) committee. They are rewarded based on the number of signatures contributed and accepted during the current DS epoch.
The Directory Service (DS) nodes handle the assembling of micro TX-blocks submitted by the shards. They also process Type II and Type III transactions that are cross-shard transactions to create another microblock. Once the assembling is done, they will form a co-signed final TX-block and broadcast it to all nodes in the Zilliqa network. The DS nodes are also rewarded based on the number of signatures contributed and accepted during the current DS epoch.
NOTE: A DS Epoch currently encompasses 100 TX Epoch in the Mao Shan Wang testnet.
More details on Epoch architecture can be found HERE.
The lookup nodes handle the dispatching of transactions to the correct shard and assist seed nodes in fetching states and transaction history. They earn 5% of the transaction fees and coinbase reward.
The seed nodes help to forward transactions to lookup nodes, assist new validating nodes in joining the network by providing the DS-blocks history, and expose transactional APIs to allow explorer/wallets to send transactions and fetch historical transaction data. They share the rewards earned by lookup nodes.
The archival storage fetches historical data including transactions and blocks from seed nodes every DS epoch and store them in LevelDB. They also provide the historical data for newly joined seed nodes.
Network map sketch
S1, S2, S3: Shards
DS: Directory service committee
SD: State delta
FB: Final block
FSD: Final state delta