Upgrade priority:
- Polkadot:❗ HIGH ❗ Please upgrade your node as soon as possible
- Kusama: Medium (timely upgrade recommended)
This is a client-only release that addresses the current 50 block finality lag on Polkadot.
As part of parachain validation the nodes must participate in the approval voting protocol, which guarantees that any parachain blocks committed on the relay chain are valid. GRANDPA voters must restrict their votes to relay chain blocks that only include parachain blocks that have already been approved, this guarantees that only valid parachain blocks get finalized. The client code of polkadot is shared among the multiple networks, i.e. Westend, Kusama and Polkadot, and this logic for restricting votes on finality is already enabled and working on both Westend and Kusama since these networks have already rolled out parachains support. Since parachains support on Polkadot has not been rolled out yet, this logic made it so that the node would not find any approved blocks (since the approval voting protocol is not running), which caused the voters to restrict their votes for finality.
This release should only affect Polkadot nodes, once more than 2/3 of the validators upgrade to v0.9.6, the finality lag should go back to the previous values (i.e. 2 or 3 blocks behind best).
Native runtimes:
- Polkadot: 9050
- Kusama: 9050
- Westend: 9051
This release was tested against the following versions of rustc. Other versions may work.
- rustc 1.52.1 (9bc8c42bb 2021-05-09)
- rustc 1.53.0-nightly (7f4afdf02 2021-04-22)