Shelley Rollout weekly update w/e 24 July

So… we’re in the home straight now. On the runway. On the launchpad. Insert your favourite metaphor :slight_smile: But however you look at it, Shelley is imminent…

Over the past week, we have been working on final updates, integration and performance improvements. Managing all the different workstreams and coordinating their final deliveries has been a Herculean task. Our new logging and monitoring system has meant we have been able to easily identify bottlenecks and implement required changes. But above all else, the team has been working relentlessly, especially now that our goal is so close.

With the help of our stake pool operators, the node team has continued to test, optimise, repeat. The wallet backend team has been working around the clock to integrate the latest node modifications. The Daedalus team have been adding final UI touches and ensuring every new backend wallet element is properly integrated and tested, bringing us ever closer to the full Shelley experience.

It has been a very busy week for the team. In order to test the node, we had some pre-releases of wallets that were not stable so were swiftly retired, fixed and reuploaded. We also spun up a number of new testnet networks, based on mainnet candidate builds. Inevitably, it was going to get a little fuzzy at this point, with so much happening fast, in parallel. Thanks to our stake pool operator community for their patience and support during this busy time.

Earlier today we spun up a new testnet network, based on a new release candidate (called MC3).

A good number of stake pools have now joined the latest MC3 build testnet. This is looking very much like it is ‘the one’ – i.e. the version (give or take one or two final tweaks) that will make its way to the mainnet and also be shared with our exchange partners for integration testing. More on that a little later.


We have now arrived at the most critical point in the whole rollout. And also the most exciting.

We have just commenced the ‘countdown’ process that will transform the mainnet; from a federated Byron network into a decentralized Shelley network.

The mainnet epoch boundary started at 21:44:51 UTC tonight and around 20 minutes ago, we just submitted an update ‘proposal’. While Cardano is currently running in federated mode, the whole update process has been designed to accommodate the future on-chain governance approach of Voltaire. So in effect, the code upgrade process runs like a voting system.

So the first step is a ‘proposal’ to make a change; in this case, to implement a fundamental one to the core Cardano (Byron) codebase and migrate it to Shelley. This will commence the sequence of triggering the hardfork combinator to deploy Shelley.

For it to take full effect, it also needs to be ‘endorsed’. This is step two. Now, this doesn’t need to happen immediately. There is another window here. During this time, we can also make amendments to the initial proposal. So we plan to take full advantage of this period. Over the weekend, Alan and his QA team (plus a bevvy of volunteer testers) will put the mainnet release candidate through its final paces. We will do final stress tests and performance analysis. We do expect some ongoing performance enhancements over time, for example, in the area of CPU usage and optimisation.

If we encounter any issues, the developer team – also working this weekend – will assess these in terms of launch readiness. They will either log or address any minor issues or, if required prior to hard fork, we’ll release a new version. The migration protocol supports this and this will happen before 21:41:51 UTC on 27th July so that nodes can be restarted with the new config, and are ready to produce blocks.


Once we’re all happy, we’ll ‘endorse’ this proposal on the network (literally, a ‘vote of confidence’). With that, the blue touch paper is well and truly lit. The third and final step will see the hard fork combinator triggered and the transformation will take place at the start of the next epoch, on the 29th July at 21:44:51 UTC. Whoosh. Liftoff. And… here’s Shelley!

But let’s be clear. This is a complex procedure and we’re building Cardano to last. The Shelley protocols and parameters have undergone significant testing – by IOHK and our community pioneers – over the past months, after rigorous formal methods development.

If we do hit any issues over the weekend that we feel we need more time to address (e.g. critical integration bugs that may destabilize the network) we won’t be afraid to pause the ‘launch sequence’, regroup, fix and redeploy in the next epoch. Our confidence remains high, but this is a complex deployment and we need to build in this contingency. With such a critical upgrade to the mainnet, we shall always err on the side of caution and get it right.


So that’s the latest status on the network side. Another critical factor in successful migration is exchange integration. This is an equally complex task, but for very different reasons. Technically, we have worked hard to make upgrading relatively straightforward for our exchange partners, using our new Adrestia interfaces and libraries.

For several months, we’ve been running this as an independently resourced workstream. In collaboration with the Cardano Foundation, we’ve had a dedicated exchange relations team, focused on supporting our partners get #ReadyforShelley. Because ultimately, our exchange partners represent the final mile in the Shelley deployment. With 40+ exchanges listing Cardano and a number of other integrations (e.g. third-party wallets), this was never going to be a straightforward task. But our team has been working tirelessly to make it as smooth and easy as possible for our partners and to try to anticipate any possible glitches and minimise any exchange downtime.

We’ll share more info next week (and in our next monthly show) about the work that has been going on and what ada holders need to know about the migrations. (TL/DR your ADA will always be perfectly safe but some partners may be slower to migrate than others!) But needless to say, this is an area we continue to manage closely to try and make the whole process as smooth as possible and to minimise any exchange downtime that might be needed for exchanges to make the changes need for Shelley.

This is an incredibly exciting time, the dawn of a network evolution that will start to transform Cardano. Delegation and staking in August. A rapidly decentralized network, built by the community, for the community. More exciting still, Shelley represents just the first step in a series of network improvements over the months ahead that we believe will transform the entire industry.

See you next week.



Well written post (as always) Tim! Nice summary and tons of exciting times to come! Congrats to the team Cardano!