## Bug Explanation Adds a check that prevents finalized headers with a gap larger than the sync committee period being imported, which could cause execution headers in the gap being unprovable. The current version of the Ethereum client checks that there is a header at least every sync committee, but it doesn't check that the headers are within a sync period of each other. For example: Header 100 (sync committee period 1) Header 9000 (sync committee period 2) (8900 blocks apart) These headers are in adjacent sync committees, but more than the sync committee period (8192 blocks) apart. The reason we need a header every 8192 slots at least, is the header is used to prove messages within the last 8192 blocks. If we import header 9000, and we receive a message to be verified at header 200, the `block_roots` field of header 9000 won't contain the header in order to do the ancestry check. ## Environment While running in Rococo, this edge case was discovered after the relayer was offline for a few days. It is unlikely, but not impossible, to happen again and so it should be backported to polkadot-sdk 1.7.0 (so that [polkadot-fellows/runtimes](https://github.com/polkadot-fellows/runtimes) can be updated with the fix). Our Ethereum client has been operational on Rococo for the past few months, and this been the only major issue discovered so far. ### Unrelated Change An unrelated nit: Removes a left over file that should have been deleted when the `parachain` directory was removed. --------- Co-authored-by: claravanstaden <Cats 4 life!>
NOTE: We have recently made significant changes to our repository structure. In order to streamline our development process and foster better contributions, we have merged three separate repositories Cumulus, Substrate and Polkadot into this repository. Read more about the changes here.
Polkadot SDK
The Polkadot SDK repository provides all the resources needed to start building on the Polkadot network, a multi-chain blockchain platform that enables different blockchains to interoperate and share information in a secure and scalable way. The Polkadot SDK comprises three main pieces of software:
Polkadot
Implementation of a node for the https://polkadot.network in Rust, using the Substrate framework. This directory
currently contains runtimes for the Westend and Rococo test networks. Polkadot, Kusama and their system chain runtimes
are located in the runtimes repository maintained by
the Polkadot Technical Fellowship.
Substrate
Substrate is the primary blockchain SDK used by developers to create the parachains that make up the Polkadot network. Additionally, it allows for the development of self-sovereign blockchains that operate completely independently of Polkadot.
Cumulus
Cumulus is a set of tools for writing Substrate-based Polkadot parachains.
Releases
Note
Our release process is still Work-In-Progress and may not yet reflect the aspired outline here.
The Polkadot-SDK has two release channels: stable and nightly. Production software is advised to only use stable.
nightly is meant for tinkerers to try out the latest features. The detailed release process is described in
RELEASE.md.
Stable
stable releases have a support duration of three months. In this period, the release will not have any breaking
changes. It will receive bug fixes, security fixes, performance fixes and new non-breaking features on a two week
cadence.
Nightly
nightly releases are released every night from the master branch, potentially with breaking changes. They have
pre-release version numbers in the format major.0.0-nightlyYYMMDD.
Upstream Dependencies
Below are the primary upstream dependencies utilized in this project:
Security
The security policy and procedures can be found in docs/contributor/SECURITY.md.
Contributing & Code of Conduct
Ensure you follow our contribution guidelines. In every interaction and contribution, this project adheres to the Contributor Covenant Code of Conduct.
Additional Resources
- For monitoring upcoming changes and current proposals related to the technical implementation of the Polkadot network,
visit the
Requests for Comment (RFC)repository. While it's maintained by the Polkadot Fellowship, the RFC process welcomes contributions from everyone.
