When accessing DB in `readOnly` mode that does not already have latest
schema, initial writes trigger `attempt to write a readonly database`.
Avoid that by only writing schema when DB is not `readOnly`, and provide
data from legacy tables if such are present.
When running `nimbus_light_client`, we persist the latest header from
`LightClientStore.finalized_header` in a database across restarts.
Because the data format is derived from the latest `LightClientStore`,
this could lead to data being persisted in pre-release formats.
To enable us to test later `LightClientStore` versions on devnets,
transition to a `ForkedLightClientStore` internally that is only
migrated to newer forks on-demand (instead of starting at latest).
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.
* fix obtaining deposits after connection loss
When an error occurs during Eth1 deposits import, the already imported
blocks are kept while the connection to the EL is re-established.
However, the corresponding merkleizer is not persisted, leading to any
future deposits no longer being properly imported. This is quite common
when syncing a fresh Nimbus instance against an already-synced Geth EL.
Fixed by persisting the head merkleizer together with the blocks.
* 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
Etan Kissling
Miran