IOHK Blog: From Byron to Shelley: Part one, the testnets

IOHK Blog: From Byron to Shelley: Part one, the testnets

The evolution to decentralization continues with a series of three Haskell Shelley testnets

April 29, 2020 Kevin Hammond 7 mins read

Following the successful Byron reboot of Cardano, we are beginning our phased transition to the Shelley mainnet. This means moving from a static, federated system to a dynamic, decentralized Cardano blockchain.

The process begins with a series of Haskell Shelley testnets, culminating in the Shelley upgrade hybrid phase.

The Haskell Shelley testnets will be a different experience from the previous Incentivized Testnet (ITN) for both stake pool operators and general users/ada holders. This is because the ITN and the Haskell testnets have been created with different goals in mind.

The ITN was designed to give stake pool operators experience in building their critical infrastructure, while allowing IOHK’s engineers to test the new incentive mechanisms with real ada, delegated by actual ada holders. The Haskell Shelley testnet is about ensuring that the Shelley mainnet is calibrated to be a best-in-class experience from day one. Unlike the ITN, the Haskell Shelley testnet will not involve ‘regular’ ada holders: the testnet will not be incentivized. Each phase is intended to run for a much shorter period – weeks rather than months. We will, of course, be testing out the operation of the wallet, explorer, and so on, but using a faucet distributing test ada that doesn’t offer rewards. Ada holders will be able to try Daedalus and the explorer on the public testnet and provide feedback, but without using real ada.

The Shelley experience will roll out within clearly defined phases. The first three phases will involve exploring and testing the new Shelley capabilities and moving to a situation where we are ready for full Shelley mainnet deployment.

Phase 1: Pioneers and the ‘Friends & Family’ phase

The rollout will begin with an invitation-only ‘friends and family’ testnet. During this phase, IOHK will first spin up and run a Shelley-only test network internally. We will then invite about 20 trusted stake pool operators – we’re calling them ‘pioneers’ – to join this (initially closed) network. These operators will comprise a small group who have demonstrated a high level of technical skill and community contribution during the ITN.

These pioneers will blaze the trail for others to follow as we head to full Shelley deployment on the Cardano mainnet. In this important first phase, we’ll be asking them to perform specific functionality tests to capture their valuable feedback while exploring the capabilities of the Haskell Shelley platform. We expect to invite more pioneers to join us – a few at a time – as we add features and prove the reliability of the testnet.

In this ‘closed alpha’ testing phase, IOHK will focus on tuning system parameters such as the saturation threshold, network resilience, and decentralization. Furthermore, IOHK’s engineers will see the Ouroboros Praos consensus mechanism working outside of simulation. The pioneer phase will give IOHK’s engineers the opportunity to address any issues in a controlled environment, with feedback and support from stake pool operators, before moving to the next phase. The findings will be communicated to the Cardano community and opportunities will be taken to learn about and improve the Shelley system.

This phase will also be all about producing high-quality technical documentation and support. The pioneers (supported by the community as a whole) will help us produce documentation that will make it easy to set up and run stakepools, and give our technical support team an understanding of the issues that our users will face.

Continue reading more about Phase 2 and Phase 3 here: