Adds the `--web3-url` launch argument to `nimbus_light_client` to enable
driving the EL with the optimistic head obtained from LC sync protocol.
This will keep issuing `newPayload` / `forkChoiceUpdated` requests for
new blocks, marking them as optimistic. `ZERO_HASH` is reported as the
finalized block for now.
* merge LC db into main BN db
To treat derived LC data similar to derived state caches, merge it into
the main beacon node DB.
* shorten table names, group with lc prefix
* persist LC data across restarts
With the Altair spec `LightClientUpdate` structure taking its final form
it is finally possible to persist LC data across restarts without having
to worry about data migration due to spec changes. A separate `lcdataV1`
database is created in the `caches` subdirectory to hold known LC data.
A full database with default settings (129 periods) uses <15 MB disk.
* extend LC data DB rationale
* wording
* add `isSupportedBySQLite` helper and explicit return
* remove redundant `return`
Adds a `--light-client-data-max-periods` option to override the number
of sync committee periods to retain light client data.
Raising it above the default enables archive nodes to serve full data.
Lowering below the default speeds up import times (still no persistence)
For consistency with other options, use a common prefix for light client
data configuration options.
* `--serve-light-client-data` --> `--light-client-data-serve`
* `--import-light-client-data` --> `--light-client-data-import-mode`
No deprecation of the old identifiers as they were only sparingly used
and all usage can be easily updated without interferance.
When launched with `--light-client-enable` the latest blocks are fetched
and optimistic candidate blocks are passed to a callback (log for now).
This helps accelerate syncing in the future (optimistic sync).
Adds a `LightClient` instance to the beacon node as preparation to
accelerate syncing in the future (optimistic sync).
- `--light-client-enable` turns on the feature
- `--light-client-trusted-block-root` configures block to start from
If no block root is configured, light client tracks DAG `finalizedHead`.
Introduces a new library for syncing using libp2p based light client
sync protocol, and adds a new `nimbus_light_client` executable that uses
this library for syncing. The new executable emits log messages when
new beacon block headers are received, and is integrated into testing.
* remove deprecated JSON-RPC server
* keep the command-line options around as no-ops, temporarily
* service -> server; JSON-RPC is still used elsewhere
* `gnosis-chain` -> `gnosis`
Use same name as LH/Teku throughout
* fixes#3504
* fixes large stack temporary that can cause crashes during genesis
detection
* era: load blocks and states
Era files contain finalized history and can be thought of as an
alternative source for block and state data that allows clients to avoid
syncing this information from the P2P network - the P2P network is then
used to "top up" the client with the most recent data. They can be
freely shared in the community via whatever means (http, torrent, etc)
and serve as a permanent cold store of consensus data (and, after the
merge, execution data) for history buffs and bean counters alike.
This PR gently introduces support for loading blocks and states in two
cases: block requests from rest/p2p and frontfilling when doing
checkpoint sync.
The era files are used as a secondary source if the information is not
found in the database - compared to the database, there are a few key
differences:
* the database stores the block indexed by block root while the era file
indexes by slot - the former is used only in rest, while the latter is
used both by p2p and rest.
* when loading blocks from era files, the root is no longer trivially
available - if it is needed, it must either be computed (slow) or cached
(messy) - the good news is that for p2p requests, it is not needed
* in era files, "framed" snappy encoding is used while in the database
we store unframed snappy - for p2p2 requests, the latter requires
recompression while the former could avoid it
* front-filling is the process of using era files to replace backfilling
- in theory this front-filling could happen from any block and
front-fills with gaps could also be entertained, but our backfilling
algorithm cannot take advantage of this because there's no (simple) way
to tell it to "skip" a range.
* front-filling, as implemented, is a bit slow (10s to load mainnet): we
load the full BeaconState for every era to grab the roots of the blocks
- it would be better to partially load the state - as such, it would
also be good to be able to partially decompress snappy blobs
* lookups from REST via root are served by first looking up a block
summary in the database, then using the slot to load the block data from
the era file - however, there needs to be an option to create the
summary table from era files to fully support historical queries
To test this, `ncli_db` has an era file exporter: the files it creates
should be placed in an `era` folder next to `db` in the data directory.
What's interesting in particular about this setup is that `db` remains
as the source of truth for security purposes - it stores the latest
synced head root which in turn determines where a node "starts" its
consensus participation - the era directory however can be freely shared
between nodes / people without any (significant) security implications,
assuming the era files are consistent / not broken.
There's lots of future improvements to be had:
* we can drop the in-memory `BlockRef` index almost entirely - at this
point, resident memory usage of Nimbus should drop to a cool 500-600 mb
* we could serve era files via REST trivially: this would drop backfill
times to whatever time it takes to download the files - unlike the
current implementation that downloads block by block, downloading an era
at a time almost entirely cuts out request overhead
* we can "reasonably" recreate detailed state history from almost any
point in time, turning an O(slot) process into O(1) effectively - we'll
still need caches and indices to do this with sufficient efficiency for
the rest api, but at least it cuts the whole process down to minutes
instead of hours, for arbitrary points in time
* CI: ignore failures with Nim-1.6 (temporary)
* test fixes
Co-authored-by: Ștefan Talpalaru <stefantalpalaru@yahoo.com>
Light clients require full nodes to serve additional data so that they
can stay in sync with the network. This patch adds a new launch option
`--import-light-client-data` to configure what data to make available.
For now, data is only kept in memory; it is not persisted at this time.
Note that data is only locally collected, a separate patch is needed to
actually make it availble over the network. `--serve-light-client-data`
will be used for serving data, but is not functional yet outside tests.
When performing trusted node sync, historical access is limited to
states after the checkpoint.
Reindexing restores full historical access by replaying historical
blocks against the state and storing snapshots in the database.
The process can be initiated or resumed at any point in time.
* --stop-at-synced-epoch
This allows benchmarking the initial sync (only forward sync, 1s error
margin). Might be useful in CI, with a timeout, as a sanity check.
* Support for Gnosis Chain
`make gnosis-chain-build` will build the Nimbus gnosis chain binary,
stored in `build/nimbus_beacon_node_for_gnosis_chain`.
`make gnosis-chain` will connect to the network.
Other changes:
* Restore compilation with -d:has_genesis_detection
* Removed Makefile target related to testnet0 and testnet1
* Added more debug logging for failed peer handshakes
* Report misconfigured builds which try to embed network metadata
that is incompatible with the currently selected const preset.
* Don't bundle network metadata in minimal builds, as they are not compatible
Eugene Kabanov
Jacek Sieka
Etan Kissling
tersec
zah
Ștefan Talpalaru
Tanguy