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>
This PR changes how sidechains are handled.
Before the merge, it was possible to import a chain with lower td and not set it as canonical. After the merge, we expect every chain that we get via InsertChain to be canonical. Non-canonical blocks can still be inserted
with InsertBlockWIthoutSetHead.
If during the InsertChain, the existing chain is not canonical anymore, we mark it as a sidechain and send the SideChainEvents normally.
This PR introduces a node scheme abstraction. The interface is only implemented by `hashScheme` at the moment, but will be extended by `pathScheme` very soon.
Apart from that, a few changes are also included which is worth mentioning:
- port the changes in the stacktrie, tracking the path prefix of nodes during commit
- use ethdb.Database for constructing trie.Database. This is not necessary right now, but it is required for path-based used to open reverse diff freezer
* all: work for eth1/2 transtition
* consensus/beacon, eth: change beacon difficulty to 0
* eth: updates
* all: add terminalBlockDifficulty config, fix rebasing issues
* eth: implemented merge interop spec
* internal/ethapi: update to v1.0.0.alpha.2
This commit updates the code to the new spec, moving payloadId into
it's own object. It also fixes an issue with finalizing an empty blockhash.
It also properly sets the basefee
* all: sync polishes, other fixes + refactors
* core, eth: correct semantics for LeavePoW, EnterPoS
* core: fixed rebasing artifacts
* core: light: performance improvements
* core: use keyed field (f)
* core: eth: fix compilation issues + tests
* eth/catalyst: dbetter error codes
* all: move Merger to consensus/, remove reliance on it in bc
* all: renamed EnterPoS and LeavePoW to ReachTDD and FinalizePoS
* core: make mergelogs a function
* core: use InsertChain instead of InsertBlock
* les: drop merger from lightchain object
* consensus: add merger
* core: recoverAncestors in catalyst mode
* core: fix nitpick
* all: removed merger from beacon, use TTD, nitpicks
* consensus: eth: add docstring, removed unnecessary code duplication
* consensus/beacon: better comment
* all: easy to fix nitpicks by karalabe
* consensus/beacon: verify known headers to be sure
* core: comments
* core: eth: don't drop peers who advertise blocks, nitpicks
* core: never add beacon blocks to the future queue
* core: fixed nitpicks
* consensus/beacon: simplify IsTTDReached check
* consensus/beacon: correct IsTTDReached check
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
* accounts/abi/bind: fix bounded contracts and sim backend for 1559
* accounts/abi/bind, ethclient: don't rely on chain config for gas prices
* all: enable London for all internal tests
* les: get receipt type info in les tests
* les: fix weird test
Co-authored-by: Martin Holst Swende <martin@swende.se>
* core: add test for headerchain inserts
* core, light: write headerchains in batches
* core: change to one callback per batch of inserted headers + review concerns
* core: error-check on batch write
* core: unexport writeHeaders
* core: remove callback parameter in InsertHeaderChain
The semantics of InsertHeaderChain are now much simpler: it is now an
all-or-nothing operation. The new WriteStatus return value allows
callers to check for the canonicality of the insertion. This change
simplifies use of HeaderChain in package les, where the callback was
previously used to post chain events.
* core: skip some hashing when writing headers
* core: less hashing in header validation
* core: fix headerchain flaw regarding blacklisted hashes
Co-authored-by: Felix Lange <fjl@twurst.com>
Péter Szilágyi
Marius van der Wijden
rjl493456442
Martin Holst Swende