What is a Node?
This topic is so important to us, that we even started a company to produce plug-and-play hardware so that you can run your own node, hassle-free.
“A node is a computer that is participating in the global peer-to-peer Bitcoin network. They propagate transactions and blocks everywhere. Full nodes act independently as authoritative verifiers. Onion routing. Double-spending protection. Levels of isolation for untrustworthy nodes. Why would you run one? To be in control of your money — your keys, your money. You don’t trust anyone else to tell you what the truth is, you cross-check every claim yourself. Be part of the revolution in money.
Yes, centralized cloud service providers like Amazon Web Services.
Isn’t that bizarre, a decentralized system that is mostly maintained by a centralized service provider? If, one day, AWS decided to shut down all servers running a blockchain node, many decentralized applications (dApps) would stop working. They would not have an access point to the blockchain.
If you are using MetaMask, for instance, a service which relies on Infura an infrastructure project that provides secure and scalable access to Ethereum APIs and IPFS gateways, you are also technically using AWS. All nodes that run on the Infura network, are all serviced by Amazon and operated by a single entity, ConsenSys.
The same is also true for Amazon. From one day to the next, the company could decide to bring these billions of requests to a screeching halt. Already, the decentralized Internet we imagined with Bitcoin looks to be under attack.
Full Nodes
The security and overall support of the Bitcoin blockchain are provided by full nodes. As such, these are critical to the networks and are referred to as fully validating nodes. The full nodes will be involved in the entire process of verifying transactions. The nodes also have the capacity to transmit new transactions and blocks to the network. Full nodes will usually download copies of the blockchain after every transaction and block. These full nodes are established using a wide range of software programs, with BitcoinCore being the main one.
There is a requirement to have your full node running at least six hours a day. However, it would be better if you can have it running around the clock. There are thousands of public nodes that help run the Bitcoin network and many other private ones operating behind the scenes.
Listening Nodes
The other category of nodes is known as listening or super nodes. Basically, these are nodes, which are visible to the public and will provide information to other nodes that establish a connection. For instance, The News Spy can easily connect to Bitcoin Blockchain and allow crypto users to carry out a number of transactions. These are known as super nodes as they have superior capabilities which allow them to work as a communication bridge and a source of data.
Super nodes or running nodes are always running and will have multiple established connections. In addition, it will transmit transaction data and blockchain history to different nodes all over the world. Due to the diverse and extensive functions, listening nodes demand faster internet speed and more computation power.
Miners Nodes
BTC mining is one of the common processes that go around in the cryptocurrency world. To be able to mine Bitcoin, you will need to get specialized programs and hardware. The competition is very high and any miner who wants to carry out profitable mining needs to up their game. As a miner, you have the liberty to work alone or join a mining pool. Solo miners will need to have full nodes so that they can be able to generate their copy of the network.
However, pool miners will pull their resources together to mine Bitcoins. In such a case, you will not provide too much hash power as there are many players on the field. The mining pool administrator is the only one required to have a full node so as to support the other miners.
What Are Nodes?
Depending upon the purpose served, the definition of nodes varies from application to application. In context to a Blockchain network, nodes are the electronic devices connected to the network and possessing an IP address. Generally, nodes are the communication endpoints which means that any user or application that wants to interact with the Blockchain does so through nodes. Therefore, nodes are also a point of communication redistribution.
It is a common misconception that all nodes are thought to provide the same functionality or even all the users interacting with the Blockchain are often considered to be a node.
There are two things to be considered here. One, every device connected to the Blockchain network is not necessarily a node. Two, every node on the Blockchain network does not carry out the same functionality.
Nodes are classified based on distinct roles played inside the Blockchain ecosystem. While generally, a node is responsible for maintaining the transaction record of the Blockchain, there are other nodes that are not required to keep this record.
The different roles played by nodes in a Blockchain network are defined by the requirements of that particular Blockchain network.
For instance, the Corda Blockchain has two types of nodes, one for the client and one for the digital notary that validates the transactions.
Another prominent example is the Hyperledger Fabric Blockchain Network that requires multiple roles to provide a modular architecture. This includes a node for a Membership Service Provider, Users, Endorsers, Anchors, and more such entities.
The purpose of defining different roles is to allow the Blockchain to operate in a seamless fashion as every node is responsible for completing a defined number of tasks.
What Does a Blockchain Node Do?
Depending upon the Blockchain, there can be innumerable roles based on certain tasks but the basic functions of a node come down to:
- Accepting or rejecting transactions
- Managing the transactions and their validity
- Storing the cryptographically linked blocks
- Acting as a point of communication.
Let us take a deep dive into the common tasks that a node is usually responsible to complete:
Processing A Transaction
Any transaction done on the Blockchain is sent to nodes of that Blockchain network. Based on their roles, some nodes take part in the consensus algorithm of the network to validate the transaction and some nodes are just responsible for keeping the record.
In this scenario, the node receives a transaction, accepts or rejects the transaction, records the data, and sends the data back to the peers. Sometimes, the node is required to share this data with other nodes to maintain the synchronization. This is how blockchain records transactions.
Accommodating Blockchain
Nodes are not only responsible for maintaining the Blockchain but also to support its growth. Every new block of data which has to be added to the Blockchain is basically added to the node’s storage. Nodes add blocks to the Blockchain and then sync up to maintain a single copy of the ledger. The process of block creation and transaction validation, however, is done through the consensus algorithm.
Access
Nodes ensure that users have unabated access to the Blockchain ledger. If you have been to any Blockchain explorer such as Etherescan to view various transactions happening over the Ethereum network or to get details of a transaction based on its transaction id, you are actually interacting with a node. The block explorer is just an interface that connects with a node and fetches data from the node.
Therefore, nodes are responsible for providing access to the data that has been stored on the Blockchain. However, this is based on the assumption that the node is actually storing the data because as mentioned earlier in this article, there are different types of nodes in Blockchain.