1. What is a Node?
A node is a computer running Ethereum client software, connected to other nodes to form a
decentralized network. These nodes collaboratively verify transactions and maintain the blockchain's
shared ledger. Instead of relying on a centralized database, nodes act as distributed databases
accessible by everyone, ensuring the security and decentralization of the system. With the
transition from Proof of Work (PoW) to Proof of Stake (PoS) after The Merge in September 2022,
Ethereum nodes now require running two clients: the execution client and the consensus client.
2. Types of Nodes
2.1. Archive Nodes
Archive Nodes store comprehensive data within the blockchain, including the entire transaction
history from the Genesis Block. They retain all historical states, making them useful for querying
past blockchain data that is not accessible on Full Nodes. Archive Nodes are not involved in block
validation.
Recommended Hardware Requirements:
- A fast CPU with 4+ cores
- 16 GB+ of RAM
- High storage capacity depending on the client software (e.g., ~13.5 TB for Geth, ~2-3 TB for
Erigon as of March 2023)
- 25 MBit/s bandwidth
2.2. Full (Non-Consensus) Nodes
Full Nodes maintain the current Blockchain State and store recent block data (typically the last 128
blocks). They validate all blocks and states and serve blockchain data upon request. These nodes
support the network by participating in block validation, even though they do not store the entire
blockchain history.
Recommended Hardware Requirements:
- A fast CPU with 4+ cores
- 16 GB+ of RAM
- At least 1 TB of fast SSD storage
- 25 MBit/s bandwidth
2.3. Validator/Miner (Consensus) Nodes
Consensus Nodes are integral to block production and validation in both PoW and PoS-based
blockchains. Miners and validators operate as Consensus Nodes, contributing to the network’s
security and functionality.
2.4. Light (SPV) Nodes
Light Nodes validate transactions without downloading the entire blockchain data. These nodes
typically power wallet applications, requiring less data than Full Nodes but providing reduced
security.
2.5. Stateless Nodes
Stateless Nodes represent a future evolution, enabling validation without downloading the Blockchain
State. They aim to improve blockchain scalability.
3. The Importance of Running a Node
Running a node is essential for decentralization and security in the Ethereum network. Nodes,
including Non-Consensus Nodes, help maintain the network's integrity by participating in validation
processes. Running a node also allows users to interact directly with Ethereum, ensuring control
over their interactions with the blockchain.
4. The Future of Nodes
Nodes will continue to be crucial for the future of blockchain technologies. Innovations like
Stateless Nodes and Light Nodes aim to create a more decentralized and scalable blockchain network,
enhancing Ethereum’s long-term viability.
5. Recommendations When Choosing Hardware to Run a Node
When selecting hardware to run an Ethereum node, prioritize the following:
- CPU: Opt for a processor with strong single-core performance, as the Ethereum
Virtual Machine (EVM) is not well-suited for parallel processing.
- RAM: More RAM is better for caching data, which reduces reliance on storage and
improves performance.
- Storage: Use the fastest storage available, like NVMe SSDs, but avoid QLC/PLC
flash due to performance degradation during sustained writes. Also, avoid network-attached
storage to minimize latency.
These considerations are crucial for maintaining optimal performance and longevity of your
Ethereum node.