This is a joint announcement from Nomadic Labs, Marigold, Oxhead Alpha, Tarides and DaiLambda.
On December 4th 2021, the Tezos blockchain successfully upgraded by adopting Hangzhou at block 1,916,929. Hangzhou was jointly developed by Nomadic Labs, Marigold, Oxhead Alpha, Tarides, and DaiLambda. It follows the Granada protocol upgrade four months ago, and will be the eighth Tezos upgrade since Athens’ activation in May 2019 (overviews here and here).
Hangzhou includes numerous minor improvements to the protocol and the following substantive changes:
Timelock encryption makes it possible for smart contract authors to include strong countermeasures against Block Producer Extractable Value (elsewhere referred to as “MEV”).
Views are a new kind of entrypoints for smart contracts, which make internal state information more easily accessible to other smart contracts.
Caching provides faster access to regularly accessed data and lowers the associated gas cost. It does so by splitting state storage between a “hot” storage, kept in RAM, and a “cold” storage, kept on disk. Caching increases the throughput of Tezos and can be built upon to further improve the performance of various parts of the protocol.
- Global table of Constants
The Global Table of Constants is a feature whereby smart contract developers can register Michelson expressions as “constants” and reference them in their contracts. This allows them to create larger and more complex contracts than they would be able to otherwise. It will also serve as the foundation for smart contracts libraries in Tezos.
- Liquidity baking
Hangzhou includes a small increase to the liquidity baking sunset level. Without this, the subsidy would halt during the lifespan of this protocol.
- Context flattening
The flattening of the Context storage consists in a rewriting of the protocol’s database internals. It optimizes storage usage, and will also enable future optimisations in order to speed up the processing of blocks and operations.
As anticipated, Context flattening imposed a slowdown for archive nodes and related services. Even if the migration has taken more time than for previous releases, this delay could only be shortened due to the commitment of all bakers.
Congratulations to everyone involved in the development of this amendment and welcome to the Tezos blockchain, Hangzhou!
We intend to inject our next proposal “I” before the end of December. Stay tuned, and happy baking!