The Ethereum 2.0 Altair Beacon Chain update has gotten off to a successful start, with 98.7% of nodes already upgraded.
On Wednesday, Eth2 developer Preston Vanloon tweeted that the Altair upgrade had been “activated successfully.”
Altair is the first upgrade to the Beacon Chain since it went online in December 2020 and is likely the last before the merge with the Ethereum mainnet and the change to proof-of-stake (PoS).
The upgrade brings light-client support to the core consensus, cleans up beacon state incentive accounting, fixes some issues with validator incentives, and steps up the punitive parameters (penalties for offline validators) per Ethereum Improvement Proposal 2982.
Paul Hauner is the lead developer and reviewer of the Altair code in Lighthouse, an Ethereum 2.0 implementation.
“Altair introduced two primary changes. Firstly, it added support for light clients, which are low-resourced nodes that follow the chain with fewer features and slightly weaker security assumptions. Think of a lightweight node on your phone or in your browser. Secondly, it increased the penalties for being offline and for slashing. These penalties were set low from genesis, so we didn’t penalize users who were just learning the ropes. The merge will increase these penalties even more. Apart from these two primary changes, there was a handful of efficiency and tidiness.”
The Altair upgrade was a hard fork, meaning that any of the 250,000 or so validators who didn’t upgrade are now offline and will see their Ether (ETH) stake slowly diminish at a rate of about 10% per year.
In order to be compatible with the Altair upgrade, beacon node operators needed to update their client version, a process that only took around 10 minutes.
Although participation dropped as low as 93.3% during the first epoch after the upgrade, it quickly increased to around 95% and has since risen to around 98.7%.
“It looks like we have practically all the validators online and running Altair now. It’s hard to tell on these privacy-preserving systems, but I’d say we have no more than 1%–2% still offline,” said Hauner.
According to Beacon Chain data, this clocks in at about 247,400 active validators and 3,000 inactive validators.
Ethereum 2.0 developer Jeff Coleman tweeted, “If they don’t fix it they will cross a threshold and be ejected.”
“I believe full ejection would happen once they drop below 16 ETH, which would take a pretty long time since the network is still finalizing,” said Coleman.
“The protocol sees no difference between a validator that didn’t upgrade and one that’s just temporarily offline due to a power or network issue. Those that didn’t update just need to update and then restart their nodes. They’ll start validating again once their node catches up with the Altair chain,” explained Hauner.
The Ethereum developers will be breathing a sigh of relief as the successful upgrade means it’s full steam ahead to the merge and the scheduled aim of being ready to “switch off proof-of-work forever” by February 2022.