edbed31066 chainparams: add signet assumeutxo param at height 160_000 (Sjors Provoost)
b8cafe3871 chainparams: add testnet assumeutxo param at height 2_500_000 (Sjors Provoost)
99839bbfa7 doc: add note about confusing HaveTxsDownloaded name (James O'Beirne)
7ee46a755f contrib: add script to demo/test assumeutxo (James O'Beirne)
42cae39356 test: add feature_assumeutxo functional test (James O'Beirne)
0f64bac603 rpc: add getchainstates (James O'Beirne)
bb05857794 refuse to activate a UTXO snapshot if mempool not empty (James O'Beirne)
ce585a9a15 rpc: add loadtxoutset (James O'Beirne)
62ac519e71 validation: do not activate snapshot if behind active chain (James O'Beirne)
9511fb3616 validation: assumeutxo: swap m_mempool on snapshot activation (James O'Beirne)
7fcd21544a blockstorage: segment normal/assumedvalid blockfiles (James O'Beirne)
4c3b8ca35c validation: populate nChainTx value for assumedvalid chainstates (James O'Beirne)
49ef778158 test: adjust chainstate tests to use recognized snapshot base (James O'Beirne)
1019c39982 validation: pruning for multiple chainstates (James O'Beirne)
373cf91531 validation: indexing changes for assumeutxo (James O'Beirne)
1fffdd76a1 net_processing: validationinterface: ignore some events for bg chain (James O'Beirne)
fbe0a7d7ca wallet: validationinterface: only handle active chain notifications (James O'Beirne)
f073917a9e validationinterface: only send zmq notifications for active (James O'Beirne)
4d8f4dcb45 validation: pass ChainstateRole for validationinterface calls (James O'Beirne)
1e59acdf17 validation: only call UpdatedBlockTip for active chainstate (James O'Beirne)
c6af23c517 validation: add ChainstateRole (James O'Beirne)
9f2318c76c validation: MaybeRebalanceCaches when chain leaves IBD (James O'Beirne)
434495a8c1 chainparams: add blockhash to AssumeutxoData (James O'Beirne)
c711ca186f assumeutxo: remove snapshot during -reindex{-chainstate} (James O'Beirne)
c93ef43e4f bugfix: correct is_snapshot_cs in VerifyDB (James O'Beirne)
b73d3bbd23 net_processing: Request assumeutxo background chain blocks (Suhas Daftuar)

Pull request description:

  - Background and FAQ: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal
  - Prior progress/project: https://github.com/bitcoin/bitcoin/projects/11
  - Replaces https://github.com/bitcoin/bitcoin/pull/15606, which was closed due to Github slowness. Original description and commentary can be found there.

  ---

  This changeset finishes the first phase of the assumeutxo project. It makes UTXO snapshots loadable via RPC (`loadtxoutset`) and adds `assumeutxo` parameters to chainparams. It contains all the remaining changes necessary to both use an assumedvalid snapshot chainstate and do a full validation sync in the background.

  This may look like a lot to review, but note that
  - ~200 lines are a (non-essential) demo shell script
  - Many lines are functional test, documentation, and relatively dilute RPC code.

  So it shouldn't be as burdensome to review as the linecount might suggest.

  - **P2P**: minor changes are made to `init.cpp` and `net_processing.cpp` to make simultaneous IBD across multiple chainstates work.
  - **Pruning**: implement correct pruning behavior when using a background chainstate
  - **Blockfile separation**: to prevent "fragmentation" in blockfile storage, have background chainstates use separate blockfiles from active snapshot chainstates to avoid interleaving heights and impairing pruning.
  - **Indexing**: some `CValidationInterface` events are given with an additional parameter, ChainstateRole, and all indexers ignore events from ChainstateRole::ASSUMEDVALID so that indexation only happens sequentially.
  - Have `-reindex` properly wipe snapshot chainstates.
  - **RPC**: introduce RPC commands `loadtxoutset` and (hidden) `getchainstates`.
  - **Release docs & first assumeutxo commitment**: add notes and a particular assumeutxo hash value for first AU-enabled release.
    - This will complete the project and allow use of UTXO snapshots for faster node bootstrap.

  The next phase, if it were to be pursued, would be coming up with a way to distribute the UTXO snapshots over the P2P network.

  ---

  ### UTXO snapshots

  Create your own with `./contrib/devtools/utxo_snapshot.sh`, e.g.
  ```shell
  ./contrib/devtools/utxo_snapshot.sh 788000 utxo.dat ./src/bitcoin-cli -datadir=$(pwd)/testdata`)
  ```
  or use the pre-generated ones listed below.

  - Testnet: **2'500'000** (Sjors):
    - torrent: `magnet:?xt=urn:btih:511e09f4bf853aefab00de5c070b1e031f0ecbe9&dn=utxo-testnet-2500000.dat&tr=udp%3A%2F%2Ftracker.bitcoin.sprovoost.nl%3A6969`
    - sha256: `79db4b025448cc0ac388d8589a28eab02de53055d181e34eb47391717aa16388`
  - Signet: **160'000** (Sjors):
    - torrent: `magnet:?xt=urn:btih:9da986cb27b3980ea7fd06b21e199b148d486880&dn=utxo-signet-160000.dat&tr=udp%3A%2F%2Ftracker.bitcoin.sprovoost.nl%3A6969`
    - sha256: `eeeca845385ba91e84ef58c09d38f98f246a24feadaad57fe1e5874f3f92ef8c`
  - Mainnet: **800'000** (Sjors):
    - Note: this needs the following commit cherry-picked in: 24deb2022b
    - torrent: `magnet:?xt=urn:btih:50ee955bef37f5ec3e5b0df4cf0288af3d715a2e&dn=utxo-800000.dat&tr=udp%3A%2F%2Ftracker.bitcoin.sprovoost.nl%3A6969`

  ### Testing

  #### For fun (~5min)

  If you want to do a quick test, you can run `./contrib/devtools/test_utxo_snapshots.sh` and follow the instructions. This is mostly obviated by the functional tests, though.

  #### For real (longer)

  If you'd like to experience a real usage of assumeutxo, you can do that too.
  I've cut a new snapshot at height 788'000 (http://img.jameso.be/utxo-788000.dat - but you can do it yourself with `./contrib/devtools/utxo_snapshot.sh` if you want). Download that, and then create a datadir for testing:
  ```sh
  $ cd ~/src/bitcoin  # or whatever

  # get the snapshot
  $ curl http://img.jameso.be/utxo-788000.dat > utxo-788000.dat

  # you'll want to do this if you like copy/pasting
  $ export AU_DATADIR=/home/${USER}/au-test # or wherever

  $ mkdir ${AU_DATADIR}
  $ vim ${AU_DATADIR}/bitcoin.conf

  dbcache=8000  # or, you know, something high
  blockfilterindex=1
  coinstatsindex=1
  prune=3000
  logthreadnames=1
  ```
  Obtain this branch, build it, and then start bitcoind:
  ```sh
  $ git remote add jamesob https://github.com/jamesob/bitcoin
  $ git fetch jamesob assumeutxo
  $ git checkout jamesob/assumeutxo

  $ ./configure $conf_args && make  # (whatever you like to do here)

  # start 'er up and watch the logs
  $ ./src/bitcoind -datadir=${AU_DATADIR}
  ```
  Then, in some other window, load the snapshot
  ```sh
  $ ./src/bitcoin-cli -datadir=${AU_DATADIR} loadtxoutset $(pwd)/utxo-788000.dat
  ```

  You'll see some log messages about headers retrieval and waiting to see the snapshot in the headers chain. Once you get the full headers chain, you'll spend a decent amount of time (~10min) loading the snapshot, checking it, and flushing it to disk. After all that happens, you should be syncing to tip in pretty short order, and you'll see the occasional `[background validation]` log message go by.

  In yet another window, you can check out chainstate status with
  ```sh
  $ ./src/bitcoin-cli -datadir=${AU_DATADIR} getchainstates
  ```
  as well as usual favorites like `getblockchaininfo`.

ACKs for top commit:
  achow101:
    ACK edbed31066

Tree-SHA512: 6086fb9a38dc7df85fedc76b30084dd8154617a2a91e89a84fb41326d34ef8e7d7ea593107afba01369093bf8cc91770621d98f0ea42a5b3b99db868d2f14dc2
This commit is contained in:
Andrew Chow
2023-10-02 17:00:28 -04:00
43 changed files with 1599 additions and 291 deletions

View File

@@ -3,7 +3,7 @@
Assumeutxo is a feature that allows fast bootstrapping of a validating bitcoind
instance with a very similar security model to assumevalid.
The RPC commands `dumptxoutset` and `loadtxoutset` (yet to be merged) are used to
The RPC commands `dumptxoutset` and `loadtxoutset` are used to
respectively generate and load UTXO snapshots. The utility script
`./contrib/devtools/utxo_snapshot.sh` may be of use.

View File

@@ -0,0 +1,28 @@
Pruning
-------
When using assumeutxo with `-prune`, the prune budget may be exceeded if it is set
lower than 1100MB (i.e. `MIN_DISK_SPACE_FOR_BLOCK_FILES * 2`). Prune budget is normally
split evenly across each chainstate, unless the resulting prune budget per chainstate
is beneath `MIN_DISK_SPACE_FOR_BLOCK_FILES` in which case that value will be used.
RPC
---
`loadtxoutset` has been added, which allows loading a UTXO snapshot of the format
generated by `dumptxoutset`. Once this snapshot is loaded, its contents will be
deserialized into a second chainstate data structure, which is then used to sync to
the network's tip under a security model very much like `assumevalid`.
Meanwhile, the original chainstate will complete the initial block download process in
the background, eventually validating up to the block that the snapshot is based upon.
The result is a usable bitcoind instance that is current with the network tip in a
matter of minutes rather than hours. UTXO snapshot are typically obtained via
third-party sources (HTTP, torrent, etc.) which is reasonable since their contents
are always checked by hash.
You can find more information on this process in the `assumeutxo` design
document (<https://github.com/bitcoin/bitcoin/blob/master/doc/design/assumeutxo.md>).
`getchainstates` has been added to aid in monitoring the assumeutxo sync process.

View File

@@ -113,11 +113,11 @@ Where the 8-byte uints correspond to the mempool sequence number.
| hashtx | <32-byte transaction hash in Little Endian> | <uint32 sequence number in Little Endian>
`rawblock`: Notifies when the chain tip is updated. Messages are ZMQ multipart messages with three parts. The first part is the topic (`rawblock`), the second part is the serialized block, and the last part is a sequence number (representing the message count to detect lost messages).
`rawblock`: Notifies when the chain tip is updated. When assumeutxo is in use, this notification will not be issued for historical blocks connected to the background validation chainstate. Messages are ZMQ multipart messages with three parts. The first part is the topic (`rawblock`), the second part is the serialized block, and the last part is a sequence number (representing the message count to detect lost messages).
| rawblock | <serialized block> | <uint32 sequence number in Little Endian>
`hashblock`: Notifies when the chain tip is updated. Messages are ZMQ multipart messages with three parts. The first part is the topic (`hashblock`), the second part is the 32-byte block hash, and the last part is a sequence number (representing the message count to detect lost messages).
`hashblock`: Notifies when the chain tip is updated. When assumeutxo is in use, this notification will not be issued for historical blocks connected to the background validation chainstate. Messages are ZMQ multipart messages with three parts. The first part is the topic (`hashblock`), the second part is the 32-byte block hash, and the last part is a sequence number (representing the message count to detect lost messages).
| hashblock | <32-byte block hash in Little Endian> | <uint32 sequence number in Little Endian>