Currently, we require genesis and a checkpoint block and state to start
from an arbitrary slot - this PR relaxes this requirement so that we can
start with a state alone.
The current trusted-node-sync algorithm works by first downloading
blocks until we find an epoch aligned non-empty slot, then downloads the
state via slot.
However, current
[proposals](https://github.com/ethereum/beacon-APIs/pull/226) for
checkpointing prefer finalized state as
the main reference - this allows more simple access control and caching
on the server side - in particular, this should help checkpoint-syncing
from sources that have a fast `finalized` state download (like infura
and teku) but are slow when accessing state via slot.
Earlier versions of Nimbus will not be able to read databases created
without a checkpoint block and genesis. In most cases, backfilling makes
the database compatible except where genesis is also missing (custom
networks).
* backfill checkpoint block from libp2p instead of checkpoint source,
when doing trusted node sync
* allow starting the client without genesis / checkpoint block
* perform epoch start slot lookahead when loading tail state, so as to
deal with the case where the epoch start slot does not have a block
* replace `--blockId` with `--state-id` in TNS command line
* when replaying, also look at the parent of the last-known-block (even
if we don't have the parent block data, we can still replay from a
"parent" state) - in particular, this clears the way for implementing
state pruning
* deprecate `--finalized-checkpoint-block` option (no longer needed)
* cap maximum number of chunks to download from peer (fixes#1620)
* drop support for requesting blocks via v1 / phase0 protocol
* tighten bounds checking of fixed-size messages
In optimistic mode, Nimbus will sync optimistically even when the
execution client is offline / not available.
An optimistic node is less secure because it has not validated block
transactions via the execution client and can thus not be used for
validation duties.
* Allow chain dag without genesis / block
This PR enables the initialization of the dag without access to blocks
or genesis state - it is a prerequisite for implementing a number of
interesting features:
* checkpoint sync without any block download
* pruning of blocks and states
* backfill checkpoint block
* Fix doppelganger protection reorders validator indices in response issue.
* Add chronos metrics endpoint to nimbus REST API.
* Doppelganger protection now works on duties not on attestations.
Improve logging for doppelganger and indices.
* Improve doppelganger and indices logging.
* Add number of validators to logs.
* Move logging dumps from `debug` to `trace` level.
The LC REST API has been merged into the ethereum/beacon-APIs specs:
- https://github.com/ethereum/beacon-APIs/pull/247
Update URLs to v1 and update REST tests. Note that REST tests do not
start with Altair, so the tested BN will return empty / error responses.
Implements the latest proposal for providing LC data via REST, as of
https://github.com/ethereum/beacon-APIs/pull/247 with a v0 suffix.
Requests:
- `/eth/v0/beacon/light_client/bootstrap/{block_root}`
- `/eth/v0/beacon/light_client/updates?start_period={start_period}&count={count}`
- `/eth/v0/beacon/light_client/finality_update`
- `/eth/v0/beacon/light_client/optimistic_update`
HTTP Server-Sent Events (SSE):
- `light_client_finality_update_v0`
- `light_client_optimistic_update_v0`
Allow config of deployment phase via config instead of attempting to
derive from genesis content (when running relevant testnets), so that
we don't have to keep maintaining the list inside the binary.
The LC REST API has been merged into the ethereum/beacon-APIs specs:
- https://github.com/ethereum/beacon-APIs/pull/247
Update URLs to v1 and update REST tests. Note that REST tests do not
start with Altair, so the tested BN will return empty / error responses.
Allow config of deployment phase via config instead of attempting to
derive from genesis content (when running relevant testnets), so that
we don't have to keep maintaining the list inside the binary.
Implements the latest proposal for providing LC data via REST, as of
https://github.com/ethereum/beacon-APIs/pull/247 with a v0 suffix.
Requests:
- `/eth/v0/beacon/light_client/bootstrap/{block_root}`
- `/eth/v0/beacon/light_client/updates?start_period={start_period}&count={count}`
- `/eth/v0/beacon/light_client/finality_update`
- `/eth/v0/beacon/light_client/optimistic_update`
HTTP Server-Sent Events (SSE):
- `light_client_finality_update_v0`
- `light_client_optimistic_update_v0`
For JSON responses, "eth-consensus-version" header is handled in
`eth2_rest_serialization` for states and `rest_beacon_api` for blocks.
Align them to also be handled in `eth2_rest_serialization` for blocks.
The `ContentNotAcceptableError` is triggered when client either requests
an unsupported media type, or has form errors such as sending multiples.
Updating the description to also indicate non-supported Accept headers.
When EL `newPayload` is slow (e.g., Raspberry Pi with Besu), the epoch
and shuffling caches tend to fill up with multiple copies per epoch when
processing gossip and performing validator duties close to wall slot.
The old strategy of evicting oldest epoch led to the same item being
evicted over and over, leading to blocking of over 5 minutes in extreme
cases where alternate epochs/shuffling got loaded repeatedly.
Changing the cache eviction strategy to least-recently-used seems to
improve the situation drastically. A simple implementation was selected
based on single linked-list without a hashtable.
When backfilling LC updates (`--light-client-data-import-mode=full`),
the highest participation update is computed without ensuring that the
finalized header is in the same period. Updates sharing same period for
both finalized and attested headers should be preferred.
Fixes a bug leading to suboptimal update selection.