With Medalla, ETH 2.0 client teams move toward launch with a dress rehearsal

Last week, the Ethereum 2.0 project inched closer to its long-awaited launch with the initiation of Medalla.

Medalla is the public, multi-client testnet designed to serve as what could be called a dress rehearsal of sorts for the “phase zero” launch planned for later this year or early 2021. When Medalla went live on August 4, it was comprised of five test clients — Teku, Prysm, Nimbus, Lodestar and Lighthouse.

Combined, the teams behind these clients have attracted several million dollars in grant funding (Teku, developed by the PegaSys team, is owned by ethereum development studio ConsenSys). A total of $300,000 was granted to three of the startups by ethereum creator Vitalik Buterin back in 2018.

In sum, Medalla is an ambitious project that will play a big role in determining when phase zero kicks off. In an email to The Block, PegaSys engineer Ben Edgington wrote that Medalla “is the first testnet that has the scale, scope, and configuration of the planned Mainnet.”

“This is the first large-scale trial of something that previously has been only a spec on a screen, or just a toy network. There are many aspects of the peer-to-peer network that we need to test and optimise,” he wrote. “So far, things are looking good, but we need more time, more scale, and some more network stress until we can be really sure.”

Publicly available data, the number of validators on the network rose from roughly 20,000 to more than 26,000 as of the time of writing. An initial dearth of sufficient validators, as highlighted by developers, persisted in the moments after launch, but soon more joined in and the network began to move forward.

In an email, Prysmatic Labs co-founder Preston Van Loon explained: “The Medalla genesis launch included 5 different client implementations, more than any other multi-client testnet that has been run in the past. This testnet started off with rough participation, but was able to reach stability within a reasonable time frame and is now consistently finalizing epochs and performing nominally.”

Edgington also spoke to the progress thus far, telling The Block:

“We've now reached over a million (Goerli testnet) ETH staked, which is double the amount of Ether we need to launch Mainnet. There are 26300 validators as I write, with a 6-day queue for new validators to join. Things were a little slow to start due to initial low participation by validators — some big stakers hadn't quite got things ready in time, and we plan to allow more time when Mainnet comes (lesson learned) — but all has been running smoothly for over a week now. All teams have had some significant issues to fix during the first week, but that's what testnets are for.”

"We're looking forward to ongoing client improvements and testing paving the way for a smooth mainnet launch," Buterin told The Block in an email.

Each of the Medalla clients is different in its own way, including the programmatic language in which they’re written. Prysm is written in Go, ChainSafe’s Lodestar is written in JavaScript, Status’ Nimbus is written in Nim, Sigma Prime’s Lighthouse is written in Rust and Teku is written in Java. The ultimate goal of Medalla, as it were, is to see how multiple clients interact with one another on a shared network in an environment that’s as close to the real thing — the mainnet — as possible.

As Ethereum 2.0 project lead Danny Ryan said back in May, the inclusion of multiple clients is key for maintaining a high level of network security.

"If there's a critical bug in a single client and it goes down, the network can continue moving forward because the majority of nodes may not be running on that client,” he said at the time.

Looking ahead, the ambition for a late-2020 launch of phase zero is still in the cards. Indeed, during a recent Reddit AMA on the topic, a degree of public disagreement emerged between the Ethereum Foundations’ Justin Drake and Buterin over the timing after Drake’s note that the launch window might wind up being in early 2021.

Edgington told The Block that “there's an expectation that Medalla will run for around three months — it could be more or less, depending on how things go.”

“I expect that, if things go well, there will be a decision in around two months from now to deploy the Eth1 validator contract, which will gather the 32 Eth stakes from those who want to participate in Mainnet,” he continued. “And then, hopefully, a Mainnet beacon chain launch within 2020.”

Ultimately, the comments from the client teams struck a positive note, with Medalla’s very existence being held up as validation of a community that has spent years navigating a path toward a shift from proof-of-work to proof-of-stake.

"We are extremely optimistic about the current state of eth2 and the Medalla testnet, the initiative lead by the community is very indicative of the incredibly active Ethereum ecosystem and furthers inspires our commitment to the vision of eth2!” the ChainSafe team said in a statement.