Scaling Blockchain Horizontally: The Case for More Chains Over Bigger Blocks

Kadena’s horizontal scaling model provides a powerful foundation for building scalable applications. Whether you’re a developer looking to build the next big decentralized application or an enterprise seeking a secure, scalable blockchain solution, Kadena’s Chainweb offers a proven path forward through horizontal scalability. To be fair, this concept can be misunderstood since many other networks are racing to have larger block sizes. However, as we explain below, bigger isn’t always better.

Over the years, our community has routinely discussed block size. We’ve seen questions such as:

• When will we increase the block size?
• What impact would larger blocks have on our network?
• What are the positive or negative consequences of increasing block size?

Our team has carefully considered the limitations and potential benefits of increasing block sizes. At Kadena, we’ve opted for horizontal scaling through Chainweb, our multi-chain, Proof of Work blockchain.

The Block Size Debate… Bigger Isn’t Always Better

The larger the block does not necessarily mean larger transactions in less time. Although the logic may seem intuitive at first glance – that a larger block will result in more transactions – it overlooks several critical factors that could risk the state of our network.

Increased Validation Time and Latency

Larger blocks require more time to validate, slowing down the entire network. Every single block produced must be propagated across all nodes in the system. If a block contains more data, it will take longer for the block’s propagation to become complete. Delays will increase the chances of nodes being out of sync, which will lead to orphaned blocks. This leads to inefficiency because orphaned blocks are rejected by the network. As a result, those blocks are no longer part of the main chain.

Security Risks with Larger Blocks

Larger block sizes may result in specific security risks since they have the potential to introduce vulnerabilities during periods of high stress. In other words, when a system becomes stressed, a delay in creating larger blocks can make it easier for bad actors to exploit the network (e.g., DOS attacks and double-spend attacks).

The Cost of Disk Space

As block sizes increase, so does the amount of disk space required to store the blockchain. Fully archiving nodes would rapidly accelerate this problem, making it more difficult for regular users to run nodes, thus centralizing the network and reducing its resilience.

Why Kadena Opts for Horizontal Scaling

Chainweb’s multi-chain architecture scales our network horizontally by adding more chains. Currently, Kadena’s blockchain has 20 parallel chains operating simultaneously. Each chain is capable of processing transactions independently.

Maintaining Low Gas Fees

Chainweb distributes transaction loads across each parallel chain. By doing this, Kadena ensures equal distribution, which prevents gas fees from increasing significantly. It also helps even out the network’s stress when chains are operating in periods of high demand. For example, during times of high transaction output, transactions can be routed to another chain if the initially chosen chain becomes too busy.

Real-World Data: Kadena’s Performance Metrics

To see Kadena’s horizontal scaling in action, we can turn to data from the Kadena Block Explorer, which provides real-time insights into how the network operates.

On average, Kadena produces a block every 1.5 seconds across its 20 chains, offering a high level of throughput while keeping gas fees low. The explorer shows that Kadena’s gas fees remain minimal even during peak periods compared to other blockchains.

Further, Kadena’s orphan block rate hovers between 1-2% on its bootstrap nodes, a low figure compared to what you might see on networks that employ larger block sizes. This low orphan rate directly results from Chainweb’s ability to efficiently propagate small blocks across the network.

Chainweb: Built for Scale

The Chainweb documentation provides a detailed breakdown of Kadena’s multi-chain architecture. Each chain in the network operates independently but is linked via Merkle roots, ensuring that the entire system remains secure and consistent. This architecture allows Kadena to scale seamlessly without compromising block size or transaction speed.

Adding more chains enables Kadena to handle increasing transaction volumes without negatively impacting the system’s security or efficiency. This horizontal scalability makes Kadena one of the few blockchain platforms that can accommodate enterprise-level applications and high-throughput consumer dApps without experiencing performance bottlenecks.

Developer Insights with Chainweb’s Open-Source Implementation

For developers interested in how Kadena’s horizontal scaling is implemented, the Chainweb node repository provides an open-source look at the technology behind the network. By reviewing the repository, developers can gain insights into the architectural decisions that allow Chainweb to function as a scalable, secure multi-chain system. The codebase is designed to be modular and extensible, making it easier for developers to build on Kadena’s platform without worrying about the technical limitations that often plague single-chain systems.

Horizontal Scaling is the Future

Kadena has firmly chosen horizontal scaling through its Chainweb architecture in the ongoing debate over how to scale blockchain systems. By adding more chains rather than increasing block size, Kadena ensures low gas fees, fewer orphan blocks, and a resilient system capable of withstanding stress events. As blockchain technology grows, this approach offers the best of both worlds: scalability without sacrificing security or efficiency.

For more information on Kadena’s multi-chain architecture, visit the Chainweb documentation or explore the Chainweb node repository on GitHub.