Normally, running LC and DAG sync at same time is fine, but on tiny
devnet where some peer may not support the LC data, we can end up in
situation where peer gets disconnected when DAG is in sync, because
DAG sync never uses any req/resp on local devnet (perfect nw conditions)
so the LC sync over minutes removes the peer as sync is stuck.
We don't need to actively sync LC from network if DAG is already synced,
preventing this specific low peer devnet issue (there are others still).
LC is still locally updated when DAG finalized checkpoint advances.
* Avoid global in p2p macro (fixes#4578)
* copy p2p macro to this repo and start de-crufting it
* make protocol registration dynamic, removing light client hacks et al
* split out light client protocol into its own file
* cleanups
* Option -> Opt
* remove more cruft
* further split beacon_sync
this allows the light client to respond to peer metadata messages
without exposing the block sync protocol
* better protocol init
* "constant" protocol index
* avoid casts
* copyright
* move some discovery code to discovery
* avoid extraneous data copy when sending chunks
* remove redundant forkdigest field
* document how to connect to a specific peer
The helper function to compute delay until next light client sync task
can be useful from more general purpose contexts. Move to helpers, and
change it to return `Duration` instead of `BeaconTime` for flexibility.
- When syncing `LightClientUpdatesByRange`, and peer replies with
fewer periods than requested, no need to delay next request.
- When `FinalityUpdate` / `OptimisticUpdate` sync fails,
no need to retry immediately.
The `UpdatesByRange` API takes `startPeriod / count`, but is internally
called by `Slice`. Move the logic that converts from the `Slice` to the
caller to reduce complexity inside the used `doRequest` function.
Distinguish between those code locations that need to be updated on each
light client data format change, and those others that should generally
be fine, as long as a valid light client object is processed.
The former are tagged with static assert for `LightClientDataFork.high`.
The latter are changed to `lcDataFork > LightClientDataFork.None` to
indicate that they depend only on presence of any valid object.
Also bundled a few minor cleanups and fixes.
Also add `Forky` type for `LightClientStore` and minor fixes / cleanups.
The light client data structures were changed to accommodate additional
fields in future forks (e.g., to also hold execution data).
There is a minor change to the JSON serialization, where the `header`
properties are now nested inside a `LightClientHeader`.
The SSZ serialization remains compatible.
See https://github.com/ethereum/consensus-specs/pull/3190
and https://github.com/ethereum/beacon-APIs/pull/287
In a future fork, light client data will be extended with execution info
to support more use cases. To anticipate such an upgrade, introduce
`Forky` and `Forked` types, and ready the database schema.
Because the mapping of sync committee periods to fork versions is not
necessarily unique (fork schedule not in sync with period boundaries),
an additional column is added to `period` -> `LightClientUpdate` table.
tersec
Etan Kissling
Jacek Sieka
Eugene Kabanov
Etan Kissling