- Merge progress — minor spec updates, engineering full steam ahead
- No progress in client diversity. Be selfish, run a minority client!
First of all — fantastic work to all of the engineering teams on the Kintsugi sprint, which culminated in the launch of the Kintsugi Merge testnet. It is incredible to see 3 execution clients and 5 consensus clients for a total of 15 different pairings operating on a unified front.
Teams identified an important issue a few weeks ago. This was a mismatch in the engine API (how the PoS consensus-layer drives the execution-layer) semantics related to how execution-layer clients actually function in practice. The tl;dr is that, in some contexts, the consensus-layer was accidentally inducing unexpected load on the execution-layer.
Engineers then realized that if the engine API semantics were slightly more flexible, the two layers could work more harmoniously. This led to a subtle, yet critical, modification of the engine API and a related breaking spec release.
Today, the Kiln spec
From there, teams will transition public testnets to proof-of-stake before making mainnet preparations.
Client diversity metrics
Michael Sproul released a new wave of client diversity metrics using his novel fingerprinting mechanism. Sadly, the client distribution of validating nodes has not budged in the past 6 months.
The diversity of consensus-layer client implementations enables Ethereum and its users to have a unique and robust resilience to software failures and attacks. Users achieve some resiliance by using a minority client regardless of the network makeup, but the network itself gains resiliance at a few key validator distribution thresholds.
If a single client:
- Does not exceed 66.6%, a fault/bug in a single client cannot be finalized
- Does not exceed 50%, a fault/bug in a single client’s forkchoice cannot dominate the head of the chain
- Does not exceed 33.3%, a fault/bug in a single client cannot disrupt finality
From the looks of the fingerprinting mechanism, Prysm still sits above the 66.6% mark.
I want to give a huge shoutout to the teams, individuals, and communities taking client diversity seriously (exhibit A, exhibit B). Running a minority client is not only healthy for the network but is also safer for the individual user’s funds.
Be selfish (rational)! Run a minority client