What is parallelization, and how does it help scale a blockchain?

With the growing popularity of cryptocurrencies, there is a significant demand for the use of blockchain networks, which leads to congestion and increased fees. To solve these problems, developers are looking for and implementing solutions aimed at improving scalability. A professional blockchain software development company can help design and integrate scalable solutions that meet modern demands while maintaining security and decentralization.

One of these solutions is parallelization, that is, dividing one large task into several smaller processes that can be executed in parallel. In this article, we will examine this idea in more detail and consider how it can help decentralized networks.

What is parallelization in blockchain

Parallelization is the division of tasks into parts that are executed simultaneously. This method uses the multitasking capabilities of modern hardware, such as multi-core processors, to speed up the execution of operations.

Using it in blockchain increases network throughput by allowing multiple transactions to be verified in parallel, which is different from the traditional sequential processing approach. In parallel execution, transactions are broken down into different threads or processes, each of which is executed on a separate node.

Distributing across multiple computing processors allows for the most efficient use of available resources, resulting in reduced transaction execution times. This helps avoid the so-called “bottleneck”—network limitations that cause transactions to become slow or sluggish.

Parallelization approaches

While the basic principle of parallel execution is to process transactions simultaneously, there are two main models for implementing this concept in a blockchain.

In optimistic parallel processing, the network bypasses the transaction sorting phase and proceeds directly to processing them. The model operates under the assumption that transactions in the queue are independent and only returns to them to review incorrect executions. In this case, the system monitors the mempool, and conflicting transactions are re-executed until they are correctly processed.

In the stateful parallel processing model, transactions are organized based on their impact on the state of the network. This involves pre-grouping transactions based on their interaction with specific smart contracts or accounts. For example, those that interact with the same smart contract are considered related, while transactions that interact with different contracts without mutual influence are labeled as unrelated.

The former are executed immediately, while the latter are coordinated before processing, with gas fee-based prioritization to increase processing speed.

These models are implemented using on-chain and offline methods.

On-chain processing occurs directly in the blockchain and includes parallelization approaches such as:

• Sharding. The blockchain is distributed into several subnetworks (shards), with transactions processed independently. A single node is assigned to process only a portion of the total number of transactions, which reduces the load and increases the overall throughput.
• Special consensus mechanisms. Some consensus algorithms, such as directed acyclic graphs (DAG), facilitate simultaneous verification of transactions by a distributed array of nodes.
• Block sharding. This method segments a single block into several parts, allowing different miners to verify each shard simultaneously and independently.

Parallel processing of transactions outside the network is achieved by creating sidechains—parallel networks tied to the main one. Transactions are verified on separate chains running in parallel and then broadcast to the main network.

How parallel execution of transactions works in blockchain

While there are several approaches to parallelization in blockchain, in general the process looks like this:

• Identifying independent transactions. First, the system filters out transactions that are independent of each other, i.e. do not exchange or change the same data or state.
• Simultaneous processing. After identifying these independent transactions, they are executed simultaneously on different nodes in the network.
• Resolving dependencies and avoiding conflicts. At the final stage, the system resolves conflicts between transactions and brings the network to a consistent state using various consensus algorithms.

Pros and Cons of the approach

Parallel execution of transactions in the blockchain provides a number of advantages that solve scalability problems.

1. Reduced network congestion. Distributing transactions across multiple nodes reduces the load, especially during periods of high traffic. This method not only makes the flow of transactions more organized but also helps stabilize the size of fees.
2. Optimized hardware usage. Parallel execution takes advantage of modern multi-core processors, optimizing computing power to increase processing speed.
3. Scalability and speed. Parallel processing helps decentralized applications (dApps) run faster and process more requests. This makes blockchain applications more efficient and convenient.

Among the problems faced by the parallel processing concept are the following:

1. Higher risk of conflicts. Processing transactions simultaneously can increase the likelihood of errors, such as double spending or failures in the order of transactions, which can harm the security of the blockchain.
2. The need for complex coordination. Avoiding conflicts between concurrent transactions requires complex consistency algorithms. This can complicate development and increase computational requirements.
3. Requirement for computational resources. Parallel processing requires more computational power, which can complicate its implementation.

Conclusion

The parallel processing solution in the blockchain helps crypto projects to expand, meeting the needs of a growing number of users. Various methods contribute to increasing throughput, reducing latency, speeding up transaction confirmations, and the overall efficiency of decentralized networks.

Many blockchains have already implemented parallelization, laying the foundation for further spread of this technology, which is especially important in the context of the development of Web3 projects and attracting new users.