With the rapid development of blockchain technology, monolithic and modular architectures are emerging as important constructs. In this article, we will evaluate the main features of monolithic and modular blockchain architectures, together with their advantages and disadvantages.

The Beginning of Everything: Monolithic Blockchains

Monolithic blockchains are the first form of blockchain technology and aim to realise everything on a single chain. Examples such as Bitcoin and Ethereum are early examples of this approach. These blockchains centralise tasks such as transaction processing, validation, and agreement between nodes on a single chain.

Let's take a look at how a monolithic blockchain works,

Fundamental Components of Blockchain

Execution: This phase in a blockchain refers to the execution of transactions. For example, a user making a cryptocurrency transfer, which is executed on the blockchain, constitutes the execution phase.

Data Availability: It refers to the state that the processed data can be shared and accessed by all nodes in the network. Each node can reliably access the same data set. For example, when a cryptocurrency transaction occurs, information about this transaction is instantly shared with every node in the network, and every node can access this data reliably. This ensures that the network can easily access consistent and up-to-date data.

Consensus: A mechanism where participants in the network collaborate to add new blocks or verify transactions. This system maintains the integrity and reliability of the blockchain.

Settlement: Once transactions are completed, blocks are permanently added, and transfers are finalized. For example, when a cryptocurrency transfer is confirmed, the ledger is updated. This stage represents the final confirmation and permanent addition of transactions to the blockchain.

Let’s reinforce this information with a small example:

A user initiates a transaction (execution), which is then added to the blockchain, and shared with all nodes (data availability). Nodes reach a consensus on the transaction's validity using consensus mechanisms (consensus). Finally, the approved transaction is permanently added to the blockchain, completing the transfer (settlement). This process summarizes the basic operation of cryptocurrency transfers within a monolithic structure.

Advantages of Monolithic Architecture

1. Simplicity: The use and design of monolithic blockchains are advantageous due to their simplicity. Their singular structure simplifies code maintenance, and having all functionalities in one application can enhance code comprehensibility.

2. Security: Monolithic blockchains, which securely execute transactions on their own nodes, validate transactions after verifying transactions and achieving consensus. This increases data security and ensures the integrity of the blockchain.

Disadvantages of Monolithic Architecture

1. Scalability Issues: Monolithic applications often face scalability issues as they grow and evolve. Updating or scaling a component can affect the entire application, leading to performance issues.

2. Lack of Flexibility: Compared to modular architectures, monolithic architectures offer less flexibility. Any change or update can affect the whole system, complicating the development process.

3. State Bloat: Storing transaction data on the chain can significantly increase the size of the blockchain over time. This can lead to high hardware requirements for nodes and damage the intended decentralized structure.

A Flexible and Layered Approach: Modular Blockchains

Modular blockchains, unlike monolithic structures, introduce a layered approach to blockchain technology, aiming to balance security, scalability, and decentralization by distributing basic tasks across different layers. They offer users the opportunity to create a customizable blockchain by combining different components, allowing for efficient and flexible structures.

Exploring Some Blockchain Projects Using Modular Architecture

Celestia: Celestia is a modular Data Availability network that enables users to launch their blockchains at low cost. One of its notable features is its focus on optimizing the consensus process by concentrating on transaction ordering and securing data access. Additionally, data availability sampling allows the network to securely process more data, reducing the cost of increasing block size.

Fuel Network: An independent modular blockchain protocol from Ethereum, Fuel Network offers a flexible and scalable structure with the Sway programming language, allowing users to create their blockchains. This modular approach helps Fuel stand out by optimizing security and performance.

Avail: Avail provides a strong Data Availability layer, compatible with multiple Execution environments. Focusing on Data Availability, Avail performs block verification with minimal computational cost using erasure codes.

Besides the aforementioned projects, dozens of projects utilizing modular architecture are under development and will continue to evolve.

Advantages of Modular Architecture

1. Flexibility and Scalability: Modular architecture, by decomposing the blockchain into independent modules, offers flexibility. This allows for easy scalability and the addition of new features. Independent development of each module presents a more effective solution for scalability.

2. Reusability: Modular architecture enables certain modules to be reused in other projects or systems, speeding up the development process, reducing costs, and leveraging the benefits of previously developed successful modules.

3. Fault Isolation: In modular blockchains, a fault typically affects only the relevant module, facilitating faster detection of errors. An issue in one module does not impact the functionality of others, enhancing overall system stability.

4. Maintenance Ease: Modular chains allow each module to be independently developed and maintained, simplifying the resolution of issues or application of updates.

Disadvantages of Modular Architecture

1. Complexity: Modular architecture can complicate the system structure, and interoperability issues between different modules can make the development process challenging.

2. Compatibility and Interoperability Issues: Independently developed modules can lead to compatibility and version conflicts, potentially causing problems.

Conclusion

While monolithic blockchains offer simplicity and security advantages, they may pose limitations in scalability and flexibility. Modular blockchains, on the other hand, offer benefits like flexibility and scalability but come with disadvantages such as complexity and compatibility issues. Depending on project needs and goals, developers and organizations can choose the appropriate architecture to best leverage its advantages.