This is a follow-up PR to #29792 to get rid of the data file sync.
**This is a non-backward compatible change, which increments the
database version from 8 to 9**.
We introduce a flushOffset for each freezer table, which tracks the position
of the most recently fsync’d item in the index file. When this offset moves
forward, it indicates that all index entries below it, along with their corresponding
data items, have been properly persisted to disk. The offset can also be moved
backward when truncating from either the head or tail of the file.
Previously, the data file required an explicit fsync after every mutation, which
was highly inefficient. With the introduction of the flush offset, the synchronization
strategy becomes more flexible, allowing the freezer to sync every 30 seconds
instead.
The data items above the flush offset are regarded volatile and callers must ensure
they are recoverable after the unclean shutdown, or explicitly sync the freezer
before any proceeding operations.
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Co-authored-by: Felix Lange <fjl@twurst.com>
The total difficulty is the sum of all block difficulties from genesis
to a certain block. This value was used in PoW for deciding which chain
is heavier, and thus which chain to select. Since PoS has a different
fork selection algorithm, all blocks since the merge have a difficulty
of 0, and all total difficulties are the same for the past 2 years.
Whilst the TDs are mostly useless nowadays, there was never really a
reason to mess around removing them since they are so tiny. This
reasoning changes when we go down the path of pruned chain history. In
order to reconstruct any TD, we **must** retrieve all the headers from
chain head to genesis and then iterate all the difficulties to compute
the TD.
In a world where we completely prune past chain segments (bodies,
receipts, headers), it is not possible to reconstruct the TD at all. In
a world where we still keep chain headers and prune only the rest,
reconstructing it possible as long as we process (or download) the chain
forward from genesis, but trying to snap sync the head first and
backfill later hits the same issue, the TD becomes impossible to
calculate until genesis is backfilled.
All in all, the TD is a messy out-of-state, out-of-consensus computed
field that is overall useless nowadays, but code relying on it forces
the client into certain modes of operation and prevents other modes or
other optimizations. This PR completely nukes out the TD from the node.
It doesn't compute it, it doesn't operate on it, it's as if it didn't
even exist.
Caveats:
- Whenever we have APIs that return TD (devp2p handshake, tracer, etc.)
we return a TD of 0.
- For era files, we recompute the TD during export time (fairly quick)
to retain the format content.
- It is not possible to "verify" the merge point (i.e. with TD gone, TTD
is useless). Since we're not verifying PoW any more, just blindly trust
it, not verifying but blindly trusting the many year old merge point
seems just the same trust model.
- Our tests still need to be able to generate pre and post merge blocks,
so they need a new way to split the merge without TTD. The PR introduces
a settable ttdBlock field on the consensus object which is used by tests
as the block where originally the TTD happened. This is not needed for
live nodes, we never want to generate old blocks.
- One merge transition consensus test was disabled. With a
non-operational TD, testing how the client reacts to TTD is useless, it
cannot react.
Questions:
- Should we also drop total terminal difficulty from the genesis json?
It's a number we cannot react on any more, so maybe it would be cleaner
to get rid of even more concepts.
---------
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
Original problem was caused by #28595, where we made it so that as soon as we start to sync, the root of the disk layer is deleted. That is not wrong per se, but another part of the code uses the "presence of the root" as an init-check for the pathdb. And, since the init-check now failed, the code tried to re-initialize it which failed since a sync was already ongoing.
The total impact being: after a state-sync has begun, if the node for some reason is is shut down, it will refuse to start up again, with the error message: `Fatal: Failed to register the Ethereum service: waiting for sync.`.
This change also modifies how `geth removedb` works, so that the user is prompted for two things: `state data` and `ancient chain`. The former includes both the chaindb aswell as any state history stored in ancients.
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Co-authored-by: Martin HS <martin@swende.se>
* all: implement path-based state scheme
* all: edits from review
* core/rawdb, trie/triedb/pathdb: review changes
* core, light, trie, eth, tests: reimplement pbss history
* core, trie/triedb/pathdb: track block number in state history
* trie/triedb/pathdb: add history documentation
* core, trie/triedb/pathdb: address comments from Peter's review
Important changes to list:
- Cache trie nodes by path in clean cache
- Remove root->id mappings when history is truncated
* trie/triedb/pathdb: fallback to disk if unexpect node in clean cache
* core/rawdb: fix tests
* trie/triedb/pathdb: rename metrics, change clean cache key
* trie/triedb: manage the clean cache inside of disk layer
* trie/triedb/pathdb: move journal function
* trie/triedb/path: fix tests
* trie/triedb/pathdb: fix journal
* trie/triedb/pathdb: fix history
* trie/triedb/pathdb: try to fix tests on windows
* core, trie: address comments
* trie/triedb/pathdb: fix test issues
---------
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
This PR ports a few changes from PBSS:
- Fix the snapshot generator waiter in case the generation is not even initialized
- Refactor db inspector for ancient store
rjl493456442
Péter Szilágyi