What Are Nodes, and Why Should You Run One (on Tezos)?
A Beginners Guide to Nodes
As the popularity of cryptocurrencies and digital assets as a whole rises, we see more individuals learning about the technology behind it, blockchain. Beginners learn what mining is, what it means to validate a transaction, how consensus is reached, and how different blockchains compare with one another. A big question that comes up from this learning is, why would I run a node if it’s not validating? It is understandable that the miners continue validating transactions in exchange for monetary gain, a cryptocurrency, but what does a basic, non-validating node receive? What are the different types of nodes? Also, should I run one? To dive into this question, let’s discuss the difference between nodes.
What is a node?
A node is an operating system that is in sync with a blockchain and records the chain’s data while validating and/or injecting transactions. This is the most basic definition that encompasses the vast majority of nodes, but different types of nodes exist. Depending on the blockchain, nodes might not validate transactions or even store a record but let’s not get into those too much. Essentially, a node is a player with a specific role to play in the blockchains' ecosystem where that job is often storing and validating transactions aka, mining blocks.
What role does a node play?
The following are the most common actions a node takes, but it varies based on the blockchain. The main task is accepting or rejecting of transactions. Nodes receive transactions from users and decide whether to include it in the block or not based on storage capacity, transaction fees, and gas fees, amongst other factors. While deciding which transactions to add to the block, they must check the validity of the proposed transaction. They then must take all the transactions and store them on the node. Additionally, an important role they play is as a point of communication for users and their blockchain-based data. A block explorer like TzStats, or TzKt for the Tezos blockchain, is essentially a user interface to pull data from a full node. As you can see, nodes are the backbone of any blockchain. They provide integrity of the data, reliability, and security in a decentralized manner.
Types of Nodes
The three main types of nodes: full nodes, lightweight nodes and validator nodes. There are a few other types and subcategories of nodes depending on the protocol of the given blockchain that you can learn more about here.
Full Nodes
Full Nodes store an entire record of the blockchain’s transactions, storage, user balances, etc. Since they hold so much storage, they are very data-heavy. The Ethereum blockchain for example has ~7.5 terabytes! While full nodes don’t directly add blocks to the chain, they do validate and confirm those transactions. These full nodes have the authority to reject transactions, whether it be incorrectly formatted or a duplicate transaction that could be fraudulent. Unlike validator nodes, they don’t receive validation rewards, so they are instead run by avid community members or supported by community organizations for the sake of decentralizing the blockchain and its data.
Lightweight Nodes (AKA Light or Thin Nodes)
Each lightweight node is connected to the full nodes and relies on their information. Instead of holding the entire blockchain's information, they store the header of the blockchain and a link between the previous and current block. Essentially, they store the hashes of the blocks, while the full nodes store every transaction and full storage. Lightweight nodes are used to further decentralize the network and require less computing power and effort, so they are easier to operate. Lightweight nodes are a unique and fun way to support decentralization.
Validator Nodes
These are the big players. Validator nodes are full nodes that add blocks to the chain. These nodes are also called Mining Nodes because the process of validating is called mining on networks like Bitcoin and Ethereum. On Proof-Of-Work (PoW) networks, these validating nodes use computing power to race against each other in validating the blockchains transactions. Using the PoW method, whoever finishes the validation first earns the right to complete the block and receives the block reward. These validations of transactions are further verified by the full nodes. On Proof-Of-Stake networks, these validators are randomly selected to validate blocks based on the size of their bond. A network like Tezos uses Proof-Of-Stake and, like PoW, the full nodes verify the validator node's verification. Regardless of the consensus mechanism, the role of validating nodes is always to inject blocks to the blockchain. These are the most power-intensive and time-consuming nodes to operate.
Why should you run a Tezos Lightweight Node?
A validator on Tezos, a full node, stores the record of the chain and can inject transactions, but requires a roll of Tezos (8,000 XTZ) staked to begin validating. This 6000 XTZ is the minimum bond needed to begin validating blocks. This also requires a little more advanced level of technical knowledge. But, what about running a light node?
Operating a light node on your computer, or Raspberry Pi isn’t too complicated a task. It has never been easier to run a node as there are tons of tutorials available. For many of us who love Tezos, we want to support the decentralization of the chain, and a node is a great way to do that. Also, it is a unique, cool, indie project to have in your room or office. Show your friends the node, and make it an office desk ornament! It requires little electricity, little technical knowledge, and little time commitment. If you are interested in running one, check out how to run one on your computer here or with a Rasberry Pi here.
Here is a picture of mine!
As always, if you have any questions, please feel free to reach out to me on Twitter @adshinder and go follow @TezosIsrael to learn what we are up to!
