Part 4: Upgrades
The Bellatrix upgrade took place at 11:34:47 UTC on September the 6th, 2022.
The primary goal of Bellatrix was to ready the beacon chain for the Merge that took place nine days later. It included the following elements.
- Data structures for holding execution payloads were added, namely
- The processing of execution payloads was added to block processing.
- The fork choice was updated to recognise the transition from proof of work to proof of stake on the beacon chain side.
- The maximum size of gossip messages and Req/Resp chunks was increased in the P2P spec to allow for the extra size of beacon blocks due to the execution payload. Also, the validity rules for gossiped blocks were updated.
In addition, continuing the changes from Altair, some penalty parameters were updated to their final values. These had been softened for the pre-Merge releases as we got used to running the beacon chain:
INACTIVITY_PENALTY_QUOTIENTdecreased from to . This reduces stakes more quickly during an inactivity leak.
MIN_SLASHING_PENALTY_QUOTIENTdecreased from 64 to 32. This sets the initial slashing penalty to 1 ETH for a validator with a full stake rather than 0.5 ETH.
PROPORTIONAL_SLASHING_MULTIPLIERincreased from 2 to 3 so that, in the event of over one-third of validators being slashed together, the full penalty would be the removal of their entire stakes.
The full description of the changes between Altair and Bellatrix is in the Bellatrix specs.