aelf Vice President of Technology Peng Rong: Becoming the Champion in the Public Chain Track ælf Follow Nov 9, 2018 · 5 min read

Warren Buffett once said, “You only find out who is swimming naked after the tide goes out.”

Indeed, after a period of shaking things up, the blockchain market became significantly calmer. For many investors, it is a train headed for disaster. But for the technology-led projects, this is not a catastrophe but an ark to the new order.

Although many public chain projects have engaged in heated competitions with each other at the beginning of the year. After a market downturn, the problems that once plagued the public chain industry are still in sight. How to improve the performance of the blockchain network? How to solve congestion caused by resource occupation? How to distribute democracy through consensus?

With those questions, Golden Finance interviewed Peng Rong — aelf’s vice president of technology, who has a deep understanding of aelf’s design features and technical advantages.

Peng Rong believes that the consensus mechanism is the soul of blockchain because it determines the bookkeeping rights and affects the transaction speed. “aelf chose DPoS consensus mechanism to ensure high-frequency & stable generation of blocks. Our consensus mechanism is mainly divided into several stages: first, all the holders must vote to select the production nodes. Then, the order of production for these nodes is determined on a “per-round” basis so the elected production nodes produce blocks serially.”

He introduced that the mechanism of “determining the order of block production” will mainly use random selection, thereby reducing the influence of malicious nodes on the network. The aelf network initially has 17 production nodes, this will be increased by 2 yearly. All production nodes are assigned to a time slot each round, and the selected node produces the block within the designated time.”

After each round, an extra block is produced to calculate the production order of next round. In each round, all production nodes generate a secret random value and publish a hash of this random value. At the end of the round, all secret values ​​will be announced and used to determine the production order of next round.

In aelf’s DPoS consensus agreement, all stakeholders can vote for the proxy node, which is responsible for executing the transaction, packing the block, and generating consensus-compliant management rules. Stakeholders can also vote to decide on whether or not to update the system contract.

The rules for running the entire chain will be defined in the system contract and can only be changed in a pre-defined way (such as voting) to ensure that no hard forks of the blockchain will occur.” DPoS is mainly to solve the governance problem. To a certain extent, DPoS can also provide better processing performance. Because of the DPoS formula, the deciphering time of the delegating node is predetermined and the interval is very small.”

In order to solve the performance problem, aelf also introduced the idea of ​​parallel execution into the system. Some particularly popular contracts may have multiple transactions in the same block, and parallel transactions allow these transactions to be executed simultaneously without being tied to the processing power of a single computer.

Mainchain and Sidechains Increases available resources.

“Although we use the idea of ​​parallel execution to speed up the execution of the transaction, if there are multiple DApps in a chain, there will still be resource contention issues. It is equivalent to multiple DApps that need to use computing resources in a timely manner, a DApp using too much resource is bound to affect the execution of other DApps. To this end, aelf introduces a sidechain approach to address resource segregation issues.”

In design, each sidechain only supports one scenario, each sidechain has an exclusive set of computing resources, and the resources between each sidechain are isolated. They and do not affect each other. “For example, one sidechain is used to implement a gaming application, and the other chain implements an insurance transaction application. The two do not affect each other. This enhances the processing power of the entire platform to a certain extent. Because when one sidechain is congested, it will not affect other sidechains. The purpose of the main chain is to index the blocks generated by the sidechains, which facilitates cross-chain communication.”

The aelf sidechain network is further divided into an inner sidechain and an outer sidechain. According to Peng Rong, the internal sidechain refers to the sidechain created by aelf in the form of joint mining. In addition, mainstream chains such as Bitcoin and Ethereum can also be used as external sidechains to join aelf.

At present, aelf can also achieve the existence and timing verification of transactions through mutual indexing between sidechains.

Peng Rong explained to Golden Finance that the aelf sidechain is designed to solve two problems. The first one is resource segregation. “Because each sidechain has its own independent operating environment, it can ensure that different chains are not affected by each other. This design is parallel. (DAPPs can be divided into several different scenes, each scene runs in one sidechain which also provides the basis for solving performance problems across the platform.”

Cluster Decoupling

“The parallel execution and sidechain structure I mentioned earlier are based on cluster implementation. Each aelf node can be run based on the cluster.” Peng Rong introduced the management of the cluster by using Kubernetes, the largest management unit in the cluster. Is a chain, including the main chain and sidechains. A pod is the smallest management unit in Kubernetes, and there are multiple sets of different Pod roles in a chain. The Launcher Pod is responsible for the nodes that start the chain.

In aelf’s design, each component is modular and loosely coupled. This design allows the team to extend this module when it becomes a bottleneck. The processing power of key modules within aelf can be flexibly extended.

In 2016, Peng Rong was still working at ABC. The team at the time was working on a mutual aid project and tried to solve the problems of public transparency with blockchain technology. That is also the first time that Peng Rong has started working on a blockchain project. Years of experience in the internet industry have told Peng Rong that mobile internet is developing rapidly, and its applications can already support more than hundreds of millions of users. The engineering experience supporting internet applications have been verified.

“Now blockchain technology has gone through projects like Bitcoin and Ethereum. The ideas of cryptography and consensus involved in blockchain have also been successfully verified by these projects. Aelf combines these two proven technologies to complete the task of ensuring blockchain is widely adopted.”

Follow up:

According to Peng Rong, aelf has completed the sidechain development under the joint mining scenario and will be officially launching the main network in the first quarter of next year. The entire aelf ecosystem is planned to be completed by the end of December this year. Regarding the progress of the follow-up, Golden Finance will follow closely.