Upgrade Priority

This is a High priority release for Kusama and Polkadot, please update nodes as soon as possible.

Once enough Kusama validators have upgraded to this release, parachain block times for Kusama should significantly decrease.

Rust compiler versions

This release was compiled with following versions of rustc. Other versions may work.

• Rust Stable: rustc 1.60.0 (7737e0b5c 2022-04-04)
• Rust Nightly: rustc 1.62.0-nightly (e745b4ddb 2022-04-07)

Runtimes

This is a client only release - there will be no corresponding 9210 runtime upgrade for Polkadot or Kusama

Changes

The only notable change is #5471 - Improve dispute-coordinator message burstiness handling:

• Based on these changes on testnets, this change should decrease Parachain block times on Kusama to a significant degree.
• Previously, the dispute-coordinator was the parachain subsystem that took up a large amount of resources, causing generation of offchain information about parachain progress for the runtime to time out (the inherent data was empty and thus, no progress on enacting/backing of parachains from the runtime side could happen). This manifested in longer parachain block times. The fix to this problem is that certain internal queries of the dispute coordinator are now prioritized.
• Some more context can be found In this issue