Marcin S
0940cdd1d7
* PVF: Don't dispute on missing artifact A dispute should never be raised if the local cache doesn't provide a certain artifact. You can not dispute based on this reason, as it is a local hardware issue and not related to the candidate to check. Design: Currently we assume that if we prepared an artifact, it remains there on-disk until we prune it, i.e. we never check again if it's still there. We can change it so that instead of artifact-not-found triggering a dispute, we retry once (like we do for AmbiguousWorkerDeath, except we don't dispute if it still doesn't work). And when enqueuing an execute job, we check for the artifact on-disk, and start preparation if not found. Changes: - [x] Integration test (should fail without the following changes) - [x] Check if artifact exists when executing, prepare if not - [x] Return an internal error when file is missing - [x] Retry once on internal errors - [x] Document design (update impl guide) * Add some context to wasm error message (it is quite long) * Fix impl guide * Add check for missing/inaccessible file * Add comment referencing Substrate issue * Add test for retrying internal errors --------- Co-authored-by: parity-processbot <>
Preamble
This document aims to describe the purpose, functionality, and implementation of the host for Polkadot's parachains functionality - that is, the software which provides security and advancement for constituent parachains. It is not for the implementer of a specific parachain but rather for the implementer of the Parachain Host. In practice, this is for the implementers of Polkadot in general.
There are a number of other documents describing the research in more detail. All referenced documents will be linked here and should be read alongside this document for the best understanding of the full picture. However, this is the only document which aims to describe key aspects of Polkadot's particular instantiation of much of that research down to low-level technical details and software architecture.