What's a Blockchain Node? - Definition and Overview

May 23, 2024 4:54:22 AM

What is a Blockchain Node?

A blockchain node is a server that maintains an up-to-date copy of the blockchain ledger. The term ‘node’ comes from graph theory, representing a point of intersection or connection.

In blockchain, a node is a network participant that validates or relays transactions. Nodes communicate to exchange information and reach consensus on the blockchain’s state.

The algorithm to achieve consensus varies depending on the blockchain network’s design. Each algorithm has rules and procedures for validating transactions and adding new blocks to the blockchain.

Blockchain Node Types

Nodes maintain the blockchain, validate transactions, and participate in the consensus process. Common types are validator nodes and RPC nodes.

The number of nodes in a network can measure its decentralization and security.

Validator and Consensus Nodes

Validators mint new blocks. They ensure that transactions are valid and adhere to the network’s rules before adding them to the ledger.

Validator nodes propose blocks, which are then validated by other nodes. The consensus mechanism determines how validators are selected and how they agree on the blockchain’s state.

Node Integrity and Security

Nodes can independently verify the ledger’s integrity by checking the cryptographic signatures of blocks and transactions. This process happens locally on each node, ensuring the blockchain’s history is consistent across the network.

Even if a malicious actor controls a majority of nodes, they cannot alter the blockchain’s history or create false digital signatures. At most, they can censor, reorder, or delay transactions.

RPC and API Nodes

RPC nodes expose an API for developers to interact with the blockchain. This allows building applications that send transactions, query the blockchain’s state, and execute smart contracts. Wallets and dApps use RPC nodes to interact with the blockchain without downloading the entire ledger.

Developers can use public RPC nodes or run their own. Running an RPC node gives more control over data and security. Public RPC nodes are convenient but may have usage and data access limitations.

API nodes use standard protocols like JSON-RPC or REST. Developers can extend the functionality of RPC nodes using plugins or custom APIs.

Token Balance Tracking

The blockchain storage is optimized for fast transaction processing, not for querying token balances. Nodes can use additional plugins to track token balances and provide this information to dApps and wallets. This significantly improves the user experience at the cost of increased storage and processing requirements.

Node Configuration Overview

The easiest way to run a node is to use a pre-built client provided by the blockchain project. These clients are available for popular blockchains like Bitcoin, Ethereum, and Neo.

Download the client from GitHub or the official website and follow the installation and configuration instructions. Once started, the node will automatically connect to other nodes and start syncing the ledger. The time it takes to sync depends on the blockchain’s size, hardware, and internet connection.

Downloading a Neo Node Client

The Neo blockchain offers four main clients: Neo-GUI, Neo-CLI, Neo Go, and Neo Express:

  • Neo-GUI: A user-friendly client with a graphical interface for interacting with the Neo blockchain. It is suitable for users who prefer a visual interface. Windows only.
  • Neo-CLI: Official C# command-line client. Recommended for developers and advanced users. Available for Windows, macOS, and Linux.
  • Neo Go: An alternative Go-based client for the Neo. Available for Windows, macOS, and Linux.
  • Neo Express: A lightweight, private network client for Neo. Useful for testing and development. Available for Windows, macOS, and Linux.

Neo-CLI, Neo Go, and Neo Express support RPC interfaces and are suitable for integrating dApps and other services.

Running Node on Startup

It is recommended that nodes running on a server start automatically on system boot. Instructions for configuring this will vary depending on the operating system and setup used.

Node Hosting Services

Running a full node can be resource-intensive, requiring significant storage space and bandwidth. To simplify the process, users can use hosting services like Infura, Alchemy, or 1ClickNode. These cloud-based services provide managed nodes for popular blockchains like Ethereum, Bitcoin, and Neo.

Public Neo RPC Nodes

Neo Blockchain developers can start building applications on the Neo blockchain by using public RPC nodes. These nodes are recommended for development and testing purposes.

Visit the Dora Monitor website to find a list of public Neo RPC nodes.

Note: Public RPC nodes are not recommended for production. When deploying applications in production, run your node.

Node Syncing and Maintenance

When a new node joins the network, it must synchronize with the existing nodes to download the entire blockchain. This process can take time, depending on the size of the blockchain and the node’s internet connection. Nodes are only useful when up-to-date with the latest transactions and blocks.

In addition to syncing, nodes must be maintained to ensure they run the latest software and security patches. The blockchain’s development team commonly releases updates to fix bugs, improve performance, and enhance security.

Organizations running nodes must have a plan for maintaining and updating their infrastructure to ensure the network’s stability and security. Using node hosting services can simplify this process by handling updates and maintenance automatically.

Security Considerations

Securing your nodes is recommended to prevent spam, abuse, and unauthorized access. Common security measures include using bearer tokens for authentication, IP whitelisting to restrict access, and rate limiting. Avoid storing wallets or private keys on nodes.

If the node manages sensitive data or processes transactions, consider using a hardware security module (HSM) or secure enclave to protect cryptographic keys. Regularly audit your node’s security configuration and monitor for suspicious activity.