Artela Whitepaper
On June 20th, Artela, a cutting-edge parallel EVM Layer1 project, released the whitepaper “Full-stack Parallelization” with the aim of fully unleashing the scalability of blockchain and making DApps have “predictable performance”.
Predictable performance refers to providing DApps with predictable TPS, which is crucial for certain business scenarios. DApps deployed on public chains usually have to compete with other DApps for blockchain computing power and storage space. Therefore, in the case of network congestion, it will bring higher transaction execution costs and transaction delays to business operations, greatly restricting the rapid development of DApps. It can be imagined that if a user is unable to send and receive messages in a decentralized instant messaging software due to the block space of the underlying blockchain network being occupied by other DApps, it would be a disaster for user experience.
To solve the problem of “predictable performance”, the most common practice is to use an application-specific blockchain, also known as an appchain, which is a blockchain that specifically allocates block space for a particular application. Artela, on the other hand, innovatively proposed the solution of Elastic Block Space (EBS), which adjusts block resources dynamically based on the specific needs of DApps at the protocol level, providing independent scalable block space for high-demand DApps.
This article will introduce appchains and elastic block space separately and compare their advantages and disadvantages.
Development of Appchains
An appchain is a blockchain created to run a single DApp. Instead of building on an existing blockchain, app developers start from scratch by building a new blockchain with a customized virtual machine to execute transactions between users and the application. Developers can also customize different elements of the blockchain network stack, such as consensus, network, and execution, to meet specific design requirements and solve problems such as high congestion, high costs, and fixed features on shared networks.
Appchains are not a new concept. Bitcoin can be seen as an appchain for “digital gold,” Arweave can be seen as an appchain for permanent storage, and Celestia can be seen as an appchain for data availability. Since 2016, appchains have evolved from single-chain blockchains to multi-chain ecosystems constructed by multiple interconnected blockchains, represented by Cosmos and Polkadot. Cosmos is the first vision of a multi-chain world, dedicated to solving the cross-chain interaction problem of blockchains. It can quickly develop and launch a chain through the Cosmos SDK, designed the IBC protocol for seamless blockchain interaction, and so on. Polkadot aims to be a perfect blockchain scalability solution, and the chains in its ecosystem are called parachains. Polkadot advocates shared security from the beginning, and different parachains can communicate through cross-consensus information.
At the end of 2020, as Ethereum’s scalability research focused on solutions such as sidechains, subnets, and Layer2 Rollups, appchains also spawned corresponding forms. Sidechains like Polygon and subnets like Avalanche improve the experience and performance of sidechains or subnets to enhance overall service capabilities. Layer2 Rollups support appchains in a modular stack, and solutions like OP Stack and Polygon CDK have been welcomed by many projects. The goal of Layer2 Rollups is to increase the throughput and scalability of the Ethereum network to meet the growing transaction demand and provide broader interoperability.
Currently, many applications are built on various appchains across platforms. For example, Axie launched its Ethereum sidechain Ronin in early 2021. DeFi Kingdoms announced its migration from Harmony to the Avalanche subnet at the end of 2021. Injective launched its DeFi appchain built using the Cosmos SDK in November 2021. dYdX announced that its V4 version in mid-2022 will be built on an independent appchain using Cosmos SDK technology. Uptick Network launched the Uptick Chain, an appchain serving the development of Web3 ecosystem applications, in 2023, which includes a rich commercial protocol layer.
Advantages and Disadvantages of Appchains
Appchains have full control over their own sovereign blockchain instead of relying on the underlying Layer1. This is a double-edged sword.
Advantages include:
– Sovereignty: Appchains can solve problems through their own governance solutions, maintain the independence and autonomy of individual application projects, and prevent various interferences.
– Performance: Appchains can meet the low latency and high throughput requirements of applications, provide a good user experience, and greatly improve the operational efficiency of DApps.
– Customizability: DApp developers can customize the chain according to their needs and even create an ecosystem, providing sufficient flexibility for evolution.
Disadvantages include:
– Security issues: Appchains need to take responsibility for their own security, including balancing the number of nodes, maintaining consensus mechanisms, and avoiding staking risks, making the network relatively insecure.
– Cross-chain issues: Appchains as independent chains lack interoperability with other chains (apps) and face cross-chain problems. Integrating cross-chain protocols also increases cross-chain risks.
– Cost issues: Appchains require additional infrastructure construction, which requires a lot of costs and engineering time. Additionally, there are costs for running and maintaining nodes.
For startups, the disadvantages of appchains have a significant impact on the operation of DApps in the market. Most startup development teams cannot effectively solve security and cross-chain issues, and they are discouraged by high costs in terms of manpower, time, and money. However, predictable performance is a must-have for specific DApps. Therefore, the market urgently needs a Layer1 solution with predictable performance.
Elastic Block Space
In Web2, elastic computing is a common cloud computing model that allows systems to dynamically scale up or down computing, memory, and storage resources as needed without worrying about capacity planning and engineering design for peak usage.
Elastic block space automatically adjusts the number of transactions accommodated in blocks based on network congestion. If the blockchain network provides stable block space and TPS guarantee through elastic computing for specific application transactions, it achieves “predictable performance”.
MegaETH has also proposed a similar concept of “elastic dynamic expansion” and considered it an inevitable development path for DApps to support large-scale adoption. It predicts the following technological developments in the next 1-3 years:
– Phase One: Horizontal scaling at the validator node level.
– Phase Two: Static scaling at the chain level.
– Phase Three: Dynamic horizontal scaling at the chain level.
Artela has truly implemented this concept and solved the core problem of “how to coordinate horizontal expansion of validator nodes to support elastic computing” in the first phase. As the protocol grows in the Artela network, it can subscribe to elastic block space to handle the growth of protocol users and throughput. Elastic block space provides independent block space for DApps with high transaction throughput requirements, allowing them to scale with growth. Essentially, block space determines the amount of data each block of the blockchain can store, directly affecting transaction throughput. When DApps experience a surge in transaction demand, subscribing to elastic block space becomes useful to efficiently handle the increased load without affecting the underlying blockchain.
The implementation of elastic computing can be divided into “real-time elasticity” and “non-real-time elasticity”. “Real-time elasticity” generally refers to scaling in minutes, while “non-real-time elasticity” only needs to respond to scaling within a limited time.
Artela adopts the approach of “non-real-time elasticity”. When the network detects the need for expansion, it initiates an expansion proposal, and after one or more epochs (rather than real-time), the entire network’s validator nodes complete the expansion and submit the proof of expansion for other validators to challenge.
Artela’s solution for elastic block space draws on the concepts of distributed databases and is a continuation of blockchain sharding technology. From the perspective of “computing sharding”, it scales machine resources for application traffic with demand, avoiding the problem of “cross-shard transactions” and making the developer and user experience similar to before. At the same time, by adopting the relatively easier implementation of “non-real-time elasticity”, it enhances the applicability while meeting the practical needs of many DApps.
It is worth mentioning that as a solution for horizontally scaling blockchain performance, the prerequisite for elastic block space is “transaction parallelization”. Only when transaction parallelism is increased, the need arises to horizontally scale the machine resources of nodes to improve transaction throughput.
Therefore, for Layer1 solutions like Ethereum, the issue of transaction serialization is the most direct performance bottleneck, and the block size is limited by the variable block gas limit (up to 30,000,000 gas). Thus, Ethereum can only seek Layer2 scalability solutions.
For high-performance Layer1 solutions like Solana, although they support parallel execution of transactions and can scale horizontally, they cannot address the issue of “predictable performance” for DApps during demand peaks. Solana implements a “native fee market” solution to prevent any single-demand transaction from monopolizing scarce block space, limiting the rise in time-sensitive fees and mitigating the negative impact of sudden demand peaks. For example, during NFT issuance, NFT issuers quickly consume the computational units (CUs) limit of each account, and subsequent transactions must increase the priority fee to be processed within the limited space of that account.
It can be said that Artela’s elastic block space solution addresses the surge in transaction demand by extending the concept of the “native fee market” in Solana. It not only ensures the “predictable performance” of DApps but also prevents a surge in fees and congestion throughout the network, achieving a win-win situation.
Conclusion
Whether it is appchains or elastic block space, they are essentially solutions to address the different performance requirements of different DApps on the blockchain or the problem of “predictable performance”. There is no good or bad choice between the two solutions, only suitability or unsuitability. These two solutions remind me of the “fat protocol theory” proposed by Joel Monegro in 2016, which revolves around how “cryptographic protocols can capture more value (compared to the collective value captured by applications built on top of them)”.
Appchains are actually thin protocols, especially when Layer1 adopts a modular architecture, where the protocol layer is completely customized by the application layer. Although it brings better value accumulation mechanisms to applications, it also brings high costs and limited security.
Elastic block space is actually a fat protocol, an extension of the underlying Layer1 protocol layer, effectively reducing the entry barriers for participants with a need for “predictable performance” and allowing the protocol to capture application value, creating a positive feedback loop.
