By Nischal Shetty
Linear Scalability vs Vertical Scalability in Blockchains
In today’s world, linear scalability is a critical concept that organizations must understand to meet the needs of a universe of data and users that are growing and changing. Linear scalability in Web3 refers to the ability of a blockchain or distributed ledger system to handle a growing number of users and transactions while maintaining fast and reliable performance. It’s like having a website or app that can handle more and more people using it without slowing down or crashing.
In traditional Web2 networks and a vast majority of blockchain networks, performance is often maintained through vertical scaling i.e. by adding more power (CPU, RAM) to existing machines. Linear scaling, on the contrary, involves adding more machines/servers in a way proportional to the increase in the load on the network. And why does that matter?
The USPs of Web3 networks, especially public blockchains, are high security and decentralization so the world order of business operations is driven without intermediaries wherever possible. Instead of a centralized intermediary, public blockchains distribute the workload to multiple unrelated nodes (or validators) spread across the world to validate transactions and reach consensus on their validity. One of the core features of blockchain networks is that the individual nodes/servers operated by people will have a local copy of the network’s transaction history instead of the network storing it on centralized servers or datacenters that are vulnerable to censorship and single points of failure.
Linear Scalability is the Holy Grail for Web3 Adoption
Web3 works 24x7x365 unlike traditional institutions. That said, remember, blockchain was invented right after the 2008 financial crisis to minimize the impacts of middlemen abusing their customers’ resources and privacy. So blockchains were not conceptualized for scalability. As a result of blockchain’s additional design-build such as a consensus mechanism to ensure operations are carried out in a trustless way, and individual nodes maintain the integrity of the network, most networks today rely on vertical scalability similar to their Web2 peers to improve their throughput. Banks or corporate companies, in contrast, process transactions through trusted resources like authenticated personnel and augmented hardware devices without having to worry about scalability trilemma – a universal challenge for decentralized blockchain platforms to achieve all of its 3 desired outcomes – scalability, security and decentralization – simultaneously at any given point in time.
Blockchain networks that primarily rely on vertical scalability often encounter unwelcome consequences when their throughput capacity is throttled, particularly during periods of high traffic. They include network congestion, repeated outages, and elevated transaction fees. Such circumstances prove to be unfavorable for both users and developers engaged in building their decentralized applications (or dapps). Even in traditional systems, vertical scalability often leads to diminishing returns after a certain point in time. It further promotes the use of other stop gap measures to improve the scalability such as layer 2 solutions/networks, front-running, rollups and sidechains. Such measures improve scalability only to a very limited extent and that too by potentially compromising on decentralization and/or security. Consider this: A layer 2 scaling solution today can process a maximum of 350 TPS (transactions per second). A Web2 network like Nasdaq or Visa can process up to 10000 TPS. So how can we blame an online gaming company if they choose to use centralized services instead of Web3/blockchain despite their noble intentions?
There is no better way to help solve the scalability trilemma other than by scaling the network linearly which will allow it to maintain high decentralization, security and scalability at all times irrespective of the demand in the network. Linear scalability represents true democratic growth of a blockchain network through the community’s involvement in the form of nodes in return for an incentive (crypto’s use case started here and see how the industry is now as valuable as Apple within a few years creating a ton of jobs as we speak!)
How Can Web3 Platforms Achieve Linear Scalability?
To achieve linear scalability, you must plan, design, and implement them carefully. For systems to be able to grow linearly, they must be prepared to be distributed, able to handle problems, and highly available. Also, the workload must be spread evenly across the system using load balancing, sharding, caching, and other methods. Further, adding more resources must be done to let the system use the extra resources without creating more bottlenecks or points of failure. Getting true linear scalability in the blockchain is a difficult task that requires knowledge of distributed systems, performance optimization, and software engineering.
Sharding
The software industry has long recognized sharding centralized databases as a prime solution for scalability in various applications for decades now. In simple words, sharding breaks the job of validating and confirming transactions into small and manageable bits, or shards. This way, a blockchain network can shard its state ledger by evenly distributing – compute workload, storage, and bandwidth – among all the nodes.
Sharding, as Vitalik Buterin says, is one of the few solutions that can help blockchain networks to scale without compromising on the other 2 desired outcomes. A network could deploy various types of sharding or a combination of them that includes transaction sharding, state sharding and network sharding. For instance, dynamic state sharding is the most complex and advanced method of sharding that shards state, network and transactions on a network simultaneously. Dynamic state sharding can work hand in hand with auto-scaling the distributed data ledger which will allow the network to automatically adjust the number and size of shards based on the current workload. This helps the network to parallelize the processing of transactions while at the same time maintain atomic and cross shard composability.
Other Factors for Linear Scalability
Sharding can be combined with other features like autoscaling, composability and an optimal consensus mechanism that can ultimately help in achieving true linear scalability. In essence, a linearly scalable network should be able to increase its throughput capacity by simply adding more servers/nodes proportionally. And this is the main X factor that impacts every other outcome on a public decentralized blockchain network favorably including throughput, decentralization, security, and low transaction fees even as the usage grows.
Conclusion
Linear or horizontal scalability is critical for modern technology systems, allowing them to handle increased workloads proportionally and consistently. And this is even more true for public blockchain networks that strive to serve people in a trustless, peer to peer way (In other words, products and services are rendered by the people for the people in Web3). Achieving true linear scalability requires careful planning, design, and implementation, including distributed computing, load balancing, sharding, auto-scaling, and fault tolerance. With linear scalability, modern organizations can confidently take on any challenge and grow their systems to meet the needs of a growing and evolving universe of data and users minus any need for an intermediary.
The author is co-founder, Shardeum