Commit Graph

99 Commits

Author SHA1 Message Date
Michael Sproul
aad397f00a Resolve Rust 1.56 lints and warnings (#2728)
## Issue Addressed

When compiling with Rust 1.56.0 the compiler generates 3 instances of this warning:

```
warning: trailing semicolon in macro used in expression position
   --> common/eth2_network_config/src/lib.rs:181:24
    |
181 |                     })?;
    |                        ^
...
195 |         let deposit_contract_deploy_block = load_from_file!(DEPLOY_BLOCK_FILE);
    |                                             ---------------------------------- in this macro invocation
    |
    = note: `#[warn(semicolon_in_expressions_from_macros)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #79813 <https://github.com/rust-lang/rust/issues/79813>
    = note: this warning originates in the macro `load_from_file` (in Nightly builds, run with -Z macro-backtrace for more info)
```

This warning is completely harmless, but will be visible to users compiling Lighthouse v2.0.1 (or earlier) with Rust 1.56.0 (to be released October 21st). It is **completely safe** to ignore this warning, it's just a superficial change to Rust's syntax.

## Proposed Changes

This PR removes the semi-colon as recommended, and fixes the new Clippy lints from 1.56.0
2021-10-19 00:30:42 +00:00
Paul Hauner
e2d09bb8ac Add BeaconChainHarness::builder (#2707)
## Issue Addressed

NA

## Proposed Changes

This PR is near-identical to https://github.com/sigp/lighthouse/pull/2652, however it is to be merged into `unstable` instead of `merge-f2f`. Please see that PR for reasoning.

I'm making this duplicate PR to merge to `unstable` in an effort to shrink the diff between `unstable` and `merge-f2f` by doing smaller, lead-up PRs.

## Additional Info

NA
2021-10-14 02:58:10 +00:00
Michael Sproul
ed1fc7cca6 Fix I/O atomicity issues with checkpoint sync (#2671)
## Issue Addressed

This PR addresses an issue found by @YorickDowne during testing of v2.0.0-rc.0.

Due to a lack of atomic database writes on checkpoint sync start-up, it was possible for the database to get into an inconsistent state from which it couldn't recover without `--purge-db`. The core of the issue was that the store's anchor info was being stored _before_ the `PersistedBeaconChain`. If a crash occured so that anchor info was stored but _not_ the `PersistedBeaconChain`, then on restart Lighthouse would think the database was unitialized and attempt to compare-and-swap a `None` value, but would actually find the stale info from the previous run.

## Proposed Changes

The issue is fixed by writing the anchor info, the split point, and the `PersistedBeaconChain` atomically on start-up. Some type-hinting ugliness was required, which could possibly be cleaned up in future refactors.
2021-10-05 03:53:17 +00:00
Paul Hauner
fe52322088 Implement SSZ union type (#2579)
## Issue Addressed

NA

## Proposed Changes

Implements the "union" type from the SSZ spec for `ssz`, `ssz_derive`, `tree_hash` and `tree_hash_derive` so it may be derived for `enums`:

https://github.com/ethereum/consensus-specs/blob/v1.1.0-beta.3/ssz/simple-serialize.md#union

The union type is required for the merge, since the `Transaction` type is defined as a single-variant union `Union[OpaqueTransaction]`.

### Crate Updates

This PR will (hopefully) cause CI to publish new versions for the following crates:

- `eth2_ssz_derive`: `0.2.1` -> `0.3.0`
- `eth2_ssz`: `0.3.0` -> `0.4.0`
- `eth2_ssz_types`: `0.2.0` -> `0.2.1`
- `tree_hash`: `0.3.0` -> `0.4.0`
- `tree_hash_derive`: `0.3.0` -> `0.4.0`

These these crates depend on each other, I've had to add a workspace-level `[patch]` for these crates. A follow-up PR will need to remove this patch, ones the new versions are published.

### Union Behaviors

We already had SSZ `Encode` and `TreeHash` derive for enums, however it just did a "transparent" pass-through of the inner value. Since the "union" decoding from the spec is in conflict with the transparent method, I've required that all `enum` have exactly one of the following enum-level attributes:

#### SSZ

-  `#[ssz(enum_behaviour = "union")]`
    - matches the spec used for the merge
-  `#[ssz(enum_behaviour = "transparent")]`
    - maintains existing functionality
    - not supported for `Decode` (never was)
    
#### TreeHash

-  `#[tree_hash(enum_behaviour = "union")]`
    - matches the spec used for the merge
-  `#[tree_hash(enum_behaviour = "transparent")]`
    - maintains existing functionality

This means that we can maintain the existing transparent behaviour, but all existing users will get a compile-time error until they explicitly opt-in to being transparent.

### Legacy Option Encoding

Before this PR, we already had a union-esque encoding for `Option<T>`. However, this was with the *old* SSZ spec where the union selector was 4 bytes. During merge specification, the spec was changed to use 1 byte for the selector.

Whilst the 4-byte `Option` encoding was never used in the spec, we used it in our database. Writing a migrate script for all occurrences of `Option` in the database would be painful, especially since it's used in the `CommitteeCache`. To avoid the migrate script, I added a serde-esque `#[ssz(with = "module")]` field-level attribute to `ssz_derive` so that we can opt into the 4-byte encoding on a field-by-field basis.

The `ssz::legacy::four_byte_impl!` macro allows a one-liner to define the module required for the `#[ssz(with = "module")]` for some `Option<T> where T: Encode + Decode`.

Notably, **I have removed `Encode` and `Decode` impls for `Option`**. I've done this to force a break on downstream users. Like I mentioned, `Option` isn't used in the spec so I don't think it'll be *that* annoying. I think it's nicer than quietly having two different union implementations or quietly breaking the existing `Option` impl.

### Crate Publish Ordering

I've modified the order in which CI publishes crates to ensure that we don't publish a crate without ensuring we already published a crate that it depends upon.

## TODO

- [ ] Queue a follow-up `[patch]`-removing PR.
2021-09-25 05:58:36 +00:00
Michael Sproul
9667dc2f03 Implement checkpoint sync (#2244)
## Issue Addressed

Closes #1891
Closes #1784

## Proposed Changes

Implement checkpoint sync for Lighthouse, enabling it to start from a weak subjectivity checkpoint.

## Additional Info

- [x] Return unavailable status for out-of-range blocks requested by peers (#2561)
- [x] Implement sync daemon for fetching historical blocks (#2561)
- [x] Verify chain hashes (either in `historical_blocks.rs` or the calling module)
- [x] Consistency check for initial block + state
- [x] Fetch the initial state and block from a beacon node HTTP endpoint
- [x] Don't crash fetching beacon states by slot from the API
- [x] Background service for state reconstruction, triggered by CLI flag or API call.

Considered out of scope for this PR:

- Drop the requirement to provide the `--checkpoint-block` (this would require some pretty heavy refactoring of block verification)


Co-authored-by: Diva M <divma@protonmail.com>
2021-09-22 00:37:28 +00:00
Michael Sproul
9c785a9b33 Optimize process_attestation with active balance cache (#2560)
## Proposed Changes

Cache the total active balance for the current epoch in the `BeaconState`. Computing this value takes around 1ms, and this was negatively impacting block processing times on Prater, particularly when reconstructing states.

With a large number of attestations in each block, I saw the `process_attestations` function taking 150ms, which means that reconstructing hot states can take up to 4.65s (31 * 150ms), and reconstructing freezer states can take up to 307s (2047 * 150ms).

I opted to add the cache to the beacon state rather than computing the total active balance at the start of state processing and threading it through. Although this would be simpler in a way, it would waste time, particularly during block replay, as the total active balance doesn't change for the duration of an epoch. So we save ~32ms for hot states, and up to 8.1s for freezer states (using `--slots-per-restore-point 8192`).
2021-09-03 07:50:43 +00:00
Michael Sproul
10945e0619 Revert bad blocks on missed fork (#2529)
## Issue Addressed

Closes #2526

## Proposed Changes

If the head block fails to decode on start up, do two things:

1. Revert all blocks between the head and the most recent hard fork (to `fork_slot - 1`).
2. Reset fork choice so that it contains the new head, and all blocks back to the new head's finalized checkpoint.

## Additional Info

I tweaked some of the beacon chain test harness stuff in order to make it generic enough to test with a non-zero slot clock on start-up. In the process I consolidated all the various `new_` methods into a single generic one which will hopefully serve all future uses 🤞
2021-08-30 06:41:31 +00:00
realbigsean
303deb9969 Rust 1.54.0 lints (#2483)
## Issue Addressed

N/A

## Proposed Changes

- Removing a bunch of unnecessary references
- Updated `Error::VariantError` to `Error::Variant`
- There were additional enum variant lints that I ignored, because I thought our variant names were fine
- removed `MonitoredValidator`'s `pubkey` field, because I couldn't find it used anywhere. It looks like we just use the string version of the pubkey (the `id` field) if there is no index

## Additional Info



Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-30 01:11:47 +00:00
realbigsean
a3a7f39b0d [Altair] Sync committee pools (#2321)
Add pools supporting sync committees:
- naive sync aggregation pool
- observed sync contributions pool
- observed sync contributors pool
- observed sync aggregators pool

Add SSZ types and tests related to sync committee signatures.

Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-15 00:52:02 +00:00
Michael Sproul
371c216ac3 Use read_recursive locks in database (#2417)
## Issue Addressed

Closes #2245

## Proposed Changes

Replace all calls to `RwLock::read` in the `store` crate with `RwLock::read_recursive`.

## Additional Info

* Unfortunately we can't run the deadlock detector on CI because it's pinned to an old Rust 1.51.0 nightly which cannot compile Lighthouse (one of our deps uses `ptr::addr_of!` which is too new). A fun side-project at some point might be to update the deadlock detector.
* The reason I think we haven't seen this deadlock (at all?) in practice is that _writes_ to the database's split point are quite infrequent, and a concurrent write is required to trigger the deadlock. The split point is only written when finalization advances, which is once per epoch (every ~6 minutes), and state reads are also quite sporadic. Perhaps we've just been incredibly lucky, or there's something about the timing of state reads vs database migration that protects us.
* I wrote a few small programs to demo the deadlock, and the effectiveness of the `read_recursive` fix: https://github.com/michaelsproul/relock_deadlock_mvp
* [The docs for `read_recursive`](https://docs.rs/lock_api/0.4.2/lock_api/struct.RwLock.html#method.read_recursive) warn of starvation for writers. I think in order for starvation to occur the database would have to be spammed with so many state reads that it's unable to ever clear them all and find time for a write, in which case migration of states to the freezer would cease. If an attack could be performed to trigger this starvation then it would likely trigger a deadlock in the current code, and I think ceasing migration is preferable to deadlocking in this extreme situation. In practice neither should occur due to protection from spammy peers at the network layer. Nevertheless, it would be prudent to run this change on the testnet nodes to check that it doesn't cause accidental starvation.
2021-07-12 07:31:26 +00:00
Michael Sproul
b4689e20c6 Altair consensus changes and refactors (#2279)
## Proposed Changes

Implement the consensus changes necessary for the upcoming Altair hard fork.

## Additional Info

This is quite a heavy refactor, with pivotal types like the `BeaconState` and `BeaconBlock` changing from structs to enums. This ripples through the whole codebase with field accesses changing to methods, e.g. `state.slot` => `state.slot()`.


Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-09 06:15:32 +00:00
Mac L
406e3921d9 Use forwards iterator for state root lookups (#2422)
## Issue Addressed

#2377 

## Proposed Changes

Implement the same code used for block root lookups (from #2376) to state root lookups in order to improve performance and reduce associated memory spikes (e.g. from certain HTTP API requests).

## Additional Changes

- Tests using `rev_iter_state_roots` and `rev_iter_block_roots` have been refactored to use their `forwards` versions instead.
- The `rev_iter_state_roots` and `rev_iter_block_roots` functions are now unused and have been removed.
- The `state_at_slot` function has been changed to use the `forwards` iterator.

## Additional Info

- Some tests still need to be refactored to use their `forwards_iter` versions. These tests start their iteration from a specific beacon state and thus use the `rev_iter_state_roots_from` and `rev_iter_block_roots_from` functions. If they can be refactored, those functions can also be removed.
2021-07-06 02:38:53 +00:00
realbigsean
b84ff9f793 rust 1.53.0 updates (#2411)
## Issue Addressed

`make lint` failing on rust 1.53.0.

## Proposed Changes

1.53.0 updates

## Additional Info

I haven't figure out why yet, we were now hitting the recursion limit in a few crates. So I had to add `#![recursion_limit = "256"]` in a few places


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-06-18 05:58:01 +00:00
Paul Hauner
bf4e02e2cc Return a specific error for frozen attn states (#2384)
## Issue Addressed

NA

## Proposed Changes

Return a very specific error when at attestation reads shuffling from a frozen `BeaconState`. Previously, this was returning `MissingBeaconState` which indicates a much more serious issue.

## Additional Info

Since `get_inconsistent_state_for_attestation_verification_only` is only called once in `BeaconChain::with_committee_cache`, it is quite easy to reason about the impact of this change.
2021-06-01 06:59:43 +00:00
Paul Hauner
4c7bb4984c Use the forwards iterator more often (#2376)
## Issue Addressed

NA

## Primary Change

When investigating memory usage, I noticed that retrieving a block from an early slot (e.g., slot 900) would cause a sharp increase in the memory footprint (from 400mb to 800mb+) which seemed to be ever-lasting.

After some investigation, I found that the reverse iteration from the head back to that slot was the likely culprit. To counter this, I've switched the `BeaconChain::block_root_at_slot` to use the forwards iterator, instead of the reverse one.

I also noticed that the networking stack is using `BeaconChain::root_at_slot` to check if a peer is relevant (`check_peer_relevance`). Perhaps the steep, seemingly-random-but-consistent increases in memory usage are caused by the use of this function.

Using the forwards iterator with the HTTP API alleviated the sharp increases in memory usage. It also made the response much faster (before it felt like to took 1-2s, now it feels instant).

## Additional Changes

In the process I also noticed that we have two functions for getting block roots:

- `BeaconChain::block_root_at_slot`: returns `None` for a skip slot.
- `BeaconChain::root_at_slot`: returns the previous root for a skip slot.

I unified these two functions into `block_root_at_slot` and added the `WhenSlotSkipped` enum. Now, the caller must be explicit about the skip-slot behaviour when requesting a root. 

Additionally, I replaced `vec![]` with `Vec::with_capacity` in `store::chunked_vector::range_query`. I stumbled across this whilst debugging and made this modification to see what effect it would have (not much). It seems like a decent change to keep around, but I'm not concerned either way.

Also, `BeaconChain::get_ancestor_block_root` is unused, so I got rid of it 🗑️.

## Additional Info

I haven't also done the same for state roots here. Whilst it's possible and a good idea, it's more work since the fwds iterators are presently block-roots-specific.

Whilst there's a few places a reverse iteration of state roots could be triggered (e.g., attestation production, HTTP API), they're no where near as common as the `check_peer_relevance` call. As such, I think we should get this PR merged first, then come back for the state root iters. I made an issue here https://github.com/sigp/lighthouse/issues/2377.
2021-05-31 04:18:20 +00:00
Pawan Dhananjay
fdaeec631b Monitoring service api (#2251)
## Issue Addressed

N/A

## Proposed Changes

Adds a client side api for collecting system and process metrics and pushing it to a monitoring service.
2021-05-26 05:58:41 +00:00
Michael Sproul
f9d60f5436 VC: accept unknown fields in chain spec (#2277)
## Issue Addressed

Closes #2274

## Proposed Changes

* Modify the `YamlConfig` to collect unknown fields into an `extra_fields` map, instead of failing hard.
* Log a debug message if there are extra fields returned to the VC from one of its BNs.

This restores Lighthouse's compatibility with Teku beacon nodes (and therefore Infura)
2021-03-26 04:53:57 +00:00
Paul Hauner
015ab7d0a7 Optimize validator duties (#2243)
## Issue Addressed

Closes #2052

## Proposed Changes

- Refactor the attester/proposer duties endpoints in the BN
    - Performance improvements
    - Fixes some potential inconsistencies with the dependent root fields.
    - Removes `http_api::beacon_proposer_cache` and just uses the one on the `BeaconChain` instead.
    - Move the code for the proposer/attester duties endpoints into separate files, for readability.
- Refactor the `DutiesService` in the VC
    - Required to reduce the delay on broadcasting new blocks.
    - Gets rid of the `ValidatorDuty` shim struct that came about when we adopted the standard API.
    - Separate block/attestation duty tasks so that they don't block each other when one is slow.
- In the VC, use `PublicKeyBytes` to represent validators instead of `PublicKey`. `PublicKey` is a legit crypto object whilst `PublicKeyBytes` is just a byte-array, it's much faster to clone/hash `PublicKeyBytes` and this change has had a significant impact on runtimes.
    - Unfortunately this has created lots of dust changes.
 - In the BN, store `PublicKeyBytes` in the `beacon_proposer_cache` and allow access to them. The HTTP API always sends `PublicKeyBytes` over the wire and the conversion from `PublicKey` -> `PublickeyBytes` is non-trivial, especially when queries have 100s/1000s of validators (like Pyrmont).
 - Add the `state_processing::state_advance` mod which dedups a lot of the "apply `n` skip slots to the state" code.
    - This also fixes a bug with some functions which were failing to include a state root as per [this comment](072695284f/consensus/state_processing/src/state_advance.rs (L69-L74)). I couldn't find any instance of this bug that resulted in anything more severe than keying a shuffling cache by the wrong block root.
 - Swap the VC block service to use `mpsc` from `tokio` instead of `futures`. This is consistent with the rest of the code base.
    
~~This PR *reduces* the size of the codebase 🎉~~ It *used* to reduce the size of the code base before I added more comments. 

## Observations on Prymont

- Proposer duties times down from peaks of 450ms to consistent <1ms.
- Current epoch attester duties times down from >1s peaks to a consistent 20-30ms.
- Block production down from +600ms to 100-200ms.

## Additional Info

- ~~Blocked on #2241~~
- ~~Blocked on #2234~~

## TODO

- [x] ~~Refactor this into some smaller PRs?~~ Leaving this as-is for now.
- [x] Address `per_slot_processing` roots.
- [x] Investigate slow next epoch times. Not getting added to cache on block processing?
- [x] Consider [this](072695284f/beacon_node/store/src/hot_cold_store.rs (L811-L812)) in the scenario of replacing the state roots


Co-authored-by: pawan <pawandhananjay@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-03-17 05:09:57 +00:00
Michael Sproul
363f15f362 Use the database to persist the pubkey cache (#2234)
## Issue Addressed

Closes #1787

## Proposed Changes

* Abstract the `ValidatorPubkeyCache` over a "backing" which is either a file (legacy), or the database.
* Implement a migration from schema v2 to schema v3, whereby the contents of the cache file are copied to the DB, and then the file is deleted. The next release to include this change must be a minor version bump, and we will need to warn users of the inability to downgrade (this is our first DB schema change since mainnet genesis).
* Move the schema migration code from the `store` crate into the `beacon_chain` crate so that it can access the datadir and the `ValidatorPubkeyCache`, etc. It gets injected back into the `store` via a closure (similar to what we do in fork choice).
2021-03-04 01:25:12 +00:00
Akihito Nakano
1a22a096c6 Fix clippy errors on tests (#2160)
## Issue Addressed

There are some clippy error on tests.


## Proposed Changes

Enable clippy check on tests and fix the errors. 💪
2021-01-28 23:31:06 +00:00
realbigsean
7a71977987 Clippy 1.49.0 updates and dht persistence test fix (#2156)
## Issue Addressed

`test_dht_persistence` failing

## Proposed Changes

Bind `NetworkService::start` to an underscore prefixed variable rather than `_`.  `_` was causing it to be dropped immediately

This was failing 5/100 times before this update, but I haven't been able to get it to fail after updating it

Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-01-19 00:34:28 +00:00
blacktemplar
a28e8decbf update dependencies (#2032)
## Issue Addressed

NA

## Proposed Changes

Updates out of date dependencies.

## Additional Info

See also https://github.com/sigp/lighthouse/issues/1712 for a list of dependencies that are still out of date and the resasons.
2020-12-07 08:20:33 +00:00
blacktemplar
d8cda2d86e Fix new clippy lints (#2036)
## Issue Addressed

NA

## Proposed Changes

Fixes new clippy lints in the whole project (mainly [manual_strip](https://rust-lang.github.io/rust-clippy/master/index.html#manual_strip) and [unnecessary_lazy_evaluations](https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations)). Furthermore, removes `to_string()` calls on literals when used with the `?`-operator.
2020-12-03 01:10:26 +00:00
Michael Sproul
5828ff1204 Implement slasher (#1567)
This is an implementation of a slasher that lives inside the BN and can be enabled via `lighthouse bn --slasher`.

Features included in this PR:

- [x] Detection of attester slashing conditions (double votes, surrounds existing, surrounded by existing)
- [x] Integration into Lighthouse's attestation verification flow
- [x] Detection of proposer slashing conditions
- [x] Extraction of attestations from blocks as they are verified
- [x] Compression of chunks
- [x] Configurable history length
- [x] Pruning of old attestations and blocks
- [x] More tests

Future work:

* Focus on a slice of history separate from the most recent N epochs (e.g. epochs `current - K` to `current - M`)
* Run out-of-process
* Ingest attestations from the chain without a resync

Design notes are here https://hackmd.io/@sproul/HJSEklmPL
2020-11-23 03:43:22 +00:00
Michael Sproul
a60ab4eff2 Refine compaction (#1916)
## Proposed Changes

In an attempt to fix OOM issues and database consistency issues observed by some users after the introduction of compaction in v0.3.4, this PR makes the following changes:

* Run compaction less often: roughly every 1024 epochs, including after long periods of non-finality. I think the division check proposed by Paul is pretty solid, and ensures we don't miss any events where we should be compacting. LevelDB lacks an easy way to check the size of the DB, which would be another good trigger.
* Make it possible to disable the compaction on finalization using `--auto-compact-db=false`
* Make it possible to trigger a manual, single-threaded foreground compaction on start-up using `--compact-db`
* Downgrade the pruning log to `DEBUG`, as it's particularly noisy during sync

I would like to ship these changes to affected users ASAP, and will document them further in the Advanced Database section of the book if they prove effective.
2020-11-17 09:10:53 +00:00
Michael Sproul
556190ff46 Compact database on finalization (#1871)
## Issue Addressed

Closes #1866

## Proposed Changes

* Compact the database on finalization. This removes the deleted states from disk completely. Because it happens in the background migrator, it doesn't block other database operations while it runs. On my Medalla node it took about 1 minute and shrank the database from 90GB to 9GB.
* Fix an inefficiency in the pruning algorithm where it would always use the genesis checkpoint as the `old_finalized_checkpoint` when running for the first time after start-up. This would result in loading lots of states one-at-a-time back to genesis, and storing a lot of block roots in memory. The new code stores the old finalized checkpoint on disk and only uses genesis if no checkpoint is already stored. This makes it both backwards compatible _and_ forwards compatible -- no schema change required!
* Introduce two new `INFO` logs to indicate when pruning has started and completed. Users seem to want to know this information without enabling debug logs!
2020-11-09 07:02:21 +00:00
Michael Sproul
acd49d988d Implement database temp states to reduce memory usage (#1798)
## Issue Addressed

Closes #800
Closes #1713

## Proposed Changes

Implement the temporary state storage algorithm described in #800. Specifically:

* Add `DBColumn::BeaconStateTemporary`, for storing 0-length temporary marker values.
* Store intermediate states immediately as they are created, marked temporary. Delete the temporary flag if the block is processed successfully.
* Add a garbage collection process to delete leftover temporary states on start-up.
* Bump the database schema version to 2 so that a DB with temporary states can't accidentally be used with older versions of the software. The auto-migration is a no-op, but puts in place some infra that we can use for future migrations (e.g. #1784)

## Additional Info

There are two known race conditions, one potentially causing permanent faults (hopefully rare), and the other insignificant.

### Race 1: Permanent state marked temporary

EDIT: this has been fixed by the addition of a lock around the relevant critical section

There are 2 threads that are trying to store 2 different blocks that share some intermediate states (e.g. they both skip some slots from the current head). Consider this sequence of events:

1. Thread 1 checks if state `s` already exists, and seeing that it doesn't, prepares an atomic commit of `(s, s_temporary_flag)`.
2. Thread 2 does the same, but also gets as far as committing the state txn, finishing the processing of its block, and _deleting_ the temporary flag.
3. Thread 1 is (finally) scheduled again, and marks `s` as temporary with its transaction.
4.
    a) The process is killed, or thread 1's block fails verification and the temp flag is not deleted. This is a permanent failure! Any attempt to load state `s` will fail... hope it isn't on the main chain! Alternatively (4b) happens...
    b) Thread 1 finishes, and re-deletes the temporary flag. In this case the failure is transient, state `s` will disappear temporarily, but will come back once thread 1 finishes running.

I _hope_ that steps 1-3 only happen very rarely, and 4a even more rarely. It's hard to know

This once again begs the question of why we're using LevelDB (#483), when it clearly doesn't care about atomicity! A ham-fisted fix would be to wrap the hot and cold DBs in locks, which would bring us closer to how other DBs handle read-write transactions. E.g. [LMDB only allows one R/W transaction at a time](https://docs.rs/lmdb/0.8.0/lmdb/struct.Environment.html#method.begin_rw_txn).

### Race 2: Temporary state returned from `get_state`

I don't think this race really matters, but in `load_hot_state`, if another thread stores a state between when we call `load_state_temporary_flag` and when we call `load_hot_state_summary`, then we could end up returning that state even though it's only a temporary state. I can't think of any case where this would be relevant, and I suspect if it did come up, it would be safe/recoverable (having data is safer than _not_ having data).

This could be fixed by using a LevelDB read snapshot, but that would require substantial changes to how we read all our values, so I don't think it's worth it right now.
2020-10-23 01:27:51 +00:00
Michael Sproul
703c33bdc7 Fix head tracker concurrency bugs (#1771)
## Issue Addressed

Closes #1557

## Proposed Changes

Modify the pruning algorithm so that it mutates the head-tracker _before_ committing the database transaction to disk, and _only if_ all the heads to be removed are still present in the head-tracker (i.e. no concurrent mutations).

In the process of writing and testing this I also had to make a few other changes:

* Use internal mutability for all `BeaconChainHarness` functions (namely the RNG and the graffiti), in order to enable parallel calls (see testing section below).
* Disable logging in harness tests unless the `test_logger` feature is turned on

And chose to make some clean-ups:

* Delete the `NullMigrator`
* Remove type-based configuration for the migrator in favour of runtime config (simpler, less duplicated code)
* Use the non-blocking migrator unless the blocking migrator is required. In the store tests we need the blocking migrator because some tests make asserts about the state of the DB after the migration has run.
* Rename `validators_keypairs` -> `validator_keypairs` in the `BeaconChainHarness`

## Testing

To confirm that the fix worked, I wrote a test using [Hiatus](https://crates.io/crates/hiatus), which can be found here:

https://github.com/michaelsproul/lighthouse/tree/hiatus-issue-1557

That test can't be merged because it inserts random breakpoints everywhere, but if you check out that branch you can run the test with:

```
$ cd beacon_node/beacon_chain
$ cargo test --release --test parallel_tests --features test_logger
```

It should pass, and the log output should show:

```
WARN Pruning deferred because of a concurrent mutation, message: this is expected only very rarely!
```

## Additional Info

This is a backwards-compatible change with no impact on consensus.
2020-10-19 05:58:39 +00:00
Michael Sproul
22aedda1be
Add database schema versioning (#1688)
## Issue Addressed

Closes #673

## Proposed Changes

Store a schema version in the database so that future releases can check they're running against a compatible database version. This would also enable automatic migration on breaking database changes, but that's left as future work.

The database config is also stored in the database so that the `slots_per_restore_point` value can be checked for consistency, which closes #673
2020-10-01 11:12:36 +10:00
Adam Szkoda
d9f4819fe0 Alternative (to BeaconChainHarness) BeaconChain testing API (#1380)
The PR:

* Adds the ability to generate a crucial test scenario that isn't possible with `BeaconChainHarness` (i.e. two blocks occupying the same slot; previously forks necessitated skipping slots):

![image](https://user-images.githubusercontent.com/165678/88195404-4bce3580-cc40-11ea-8c08-b48d2e1d5959.png)

* New testing API: Instead of repeatedly calling add_block(), you generate a sorted `Vec<Slot>` and leave it up to the framework to generate blocks at those slots.
* Jumping backwards to an earlier epoch is a hard error, so that tests necessarily generate blocks in a epoch-by-epoch manner.
* Configures the test logger so that output is printed on the console in case a test fails.  The logger also plays well with `--nocapture`, contrary to the existing testing framework
* Rewrites existing fork pruning tests to use the new API
* Adds a tests that triggers finalization at a non epoch boundary slot
* Renamed `BeaconChainYoke` to `BeaconChainTestingRig` because the former has been too confusing
* Fixed multiple tests (e.g. `block_production_different_shuffling_long`, `delete_blocks_and_states`, `shuffling_compatible_simple_fork`) that relied on a weird (and accidental) feature of the old `BeaconChainHarness` that attestations aren't produced for epochs earlier than the current one, thus masking potential bugs in test cases.

Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2020-08-26 09:24:55 +00:00
Michael Sproul
4763f03dcc Fix bug in database pruning (#1564)
## Issue Addressed

Closes #1488

## Proposed Changes

* Prevent the pruning algorithm from over-eagerly deleting states at skipped slots when they are shared with the canonical chain.
* Add `debug` logging to the pruning algorithm so we have so better chance of debugging future issues from logs.
* Modify the handling of the "finalized state" in the beacon chain, so that it's always the state at the first slot of the finalized epoch (previously it was the state at the finalized block). This gives database pruning a clearer and cleaner view of things, and will marginally impact the pruning of the op pool, observed proposers, etc (in ways that are safe as far as I can tell).
* Remove duplicated `RevertedFinalizedEpoch` check from `after_finalization`
* Delete useless and unused `max_finality_distance`
* Add tests that exercise pruning with shared states at skip slots
* Delete unnecessary `block_strategy` argument from `add_blocks` and friends in the test harness (will likely conflict with #1380 slightly, sorry @adaszko -- but we can fix that)
* Bonus: add a `BeaconChain::with_head` method. I didn't end up needing it, but it turned out quite nice, so I figured we could keep it?

## Additional Info

Any users who have experienced pruning errors on Medalla will need to resync after upgrading to a release including this change. This should end unbounded `chain_db` growth! 🎉
2020-08-26 00:01:06 +00:00
Paul Hauner
61d5b592cb Memory usage reduction (#1522)
## Issue Addressed

NA

## Proposed Changes

- Adds a new function to allow getting a state with a bad state root history for attestation verification. This reduces unnecessary tree hashing during attestation processing, which accounted for 23% of memory allocations (by bytes) in a recent `heaptrack` observation.
- Don't clone caches on intermediate epoch-boundary states during block processing.
- Reject blocks that are known to fork choice earlier during gossip processing, instead of waiting until after state has been loaded (this only happens in edge-case).
- Avoid multiple re-allocations by creating a "forced" exact size iterator.

## Additional Info

NA
2020-08-17 08:05:13 +00:00
Adam Szkoda
8a1a4051cf Fix a bug in fork pruning (#1507)
Extracted from https://github.com/sigp/lighthouse/pull/1380 because merging #1380 proves to be contentious.

Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2020-08-12 07:00:00 +00:00
blacktemplar
23a8f31f83 Fix clippy warnings (#1385)
## Issue Addressed

NA

## Proposed Changes

Fixes most clippy warnings and ignores the rest of them, see issue #1388.
2020-07-23 14:18:00 +00:00
Adam Szkoda
c7f47af9fb
Harden the freezing procedure against failures (#1323)
* Enable logging in tests

* Migrate states to the freezer atomically
2020-07-03 09:47:31 +10:00
Adam Szkoda
536728b975
Write new blocks and states to the database atomically (#1285)
* Mostly atomic put_state()
* Reduce number of vec allocations
* Make crucial db operations atomic
* Save restore points
* Remove StateBatch
* Merge two HotColdDB impls
* Further reduce allocations
* Review feedback
* Silence clippy warning
2020-07-01 12:45:57 +10:00
Michael Sproul
305724770d
Bump all spec tags to v0.12.1 (#1275) 2020-06-19 11:18:27 +10:00
Michael Sproul
81c9fe3817
Apply store refactor to new fork choice 2020-06-17 15:20:44 +10:00
Adam Szkoda
9db0c28051
Make key value storage abstractions more accurate (#1267)
* Layer do_atomically() abstractions properly

* Reduce allocs and DRY get_key_for_col()

* Parameterize HotColdDB with hot and cold item stores

* -impl Store for MemoryStore

* Replace Store uses with HotColdDB

* Ditch Store trait

* cargo fmt

* Style fix

* Readd missing dep that broke the build
2020-06-16 11:34:04 +10:00
Adam Szkoda
7f036a6e95
Add error handling to iterators (#1243)
* Add error handling to iterators

* Review feedback

* Leverage itertools::process_results() in few places
2020-06-10 09:55:44 +10:00
Adam Szkoda
ce10db15da
Remove code duplicating stdlib (#1239)
* Get rid of superfluous ReverseBlockRootIterator

* Get rid of superfluous ReverseStateRootIterator and ReverseChainIterator

* cargo fmt
2020-06-02 10:41:42 +10:00
Adam Szkoda
91cb14ac41
Clean up database abstractions (#1200)
* Remove redundant method

* Pull out a method out of a struct

* More precise db access abstractions

* Move fake trait method out of it

* cargo fmt

* Fix compilation error after refactoring

* Move another fake method out the Store trait

* Get rid of superfluous method

* Fix refactoring bug

* Rename: SimpleStoreItem -> StoreItem

* Get rid of the confusing DiskStore type alias

* Get rid of SimpleDiskStore type alias

* Correction: A method took both self and a ref to Self
2020-06-01 08:13:49 +10:00
Adam Szkoda
919c81fe7d
Ditch StoreItem trait (#1185) 2020-05-25 10:26:54 +10:00
Adam Szkoda
d79e07902e
Relax PartialEq constraint on error enums (#1179) 2020-05-21 10:21:44 +10:00
Adam Szkoda
59ead67f76
Race condition fix + Reliability improvements around forks pruning (#1132)
* Improve error handling in block iteration

* Introduce atomic DB operations

* Fix race condition

An invariant was violated:  For every block hash in head_tracker, that
block is accessible from the store.
2020-05-16 13:23:32 +10:00
Thor Kamphefner
01f42a4d17
removed state-cache-size flag from beacon_node/src (#1120)
* removed state-cache-size flag from beacon_node/src
* removed state-cache-size related lines from store/src/config.rs
2020-05-14 22:34:24 +10:00
Adam Szkoda
9c3f76a33b
Prune abandoned forks (#916)
* Address compiler warning

* Prune abandoned fork choice forks

* New approach to pruning

* Wrap some block hashes in a newtype pattern

For increased type safety.

* Add Graphviz chain dump emitter for debugging

* Fix broken test case

* Make prunes_abandoned_forks use real DiskStore

* Mark finalized blocks in the GraphViz output

* Refine debug stringification of Slot and Epoch

Before this commit: print!("{:?}", Slot(123)) == "Slot(\n123\n)".
After this commit: print!("{:?", Slot(123)) == "Slot(123)".

* Simplify build_block()

* Rewrite test case using more composable test primitives

* Working rewritten test case

* Tighten fork prunning test checks

* Add another pruning test case

* Bugfix: Finalized blocks weren't always properly detected

* Pruning: Add pruning_does_not_touch_blocks_prior_to_finalization test case

* Tighten pruning tests: check if heads are tracked properly

* Add a failing test case for a buggy scenario

* Change name of function to a more accurate one

* Fix failing test case

* Test case: Were skipped slots' states pruned?

* Style fix: Simplify dereferencing

* Tighten pruning tests: check if abandoned states are deleted

* Towards atomicity of db ops

* Correct typo

* Prune also skipped slots' states

* New logic for handling skipped states

* Make skipped slots test pass

* Post conflict resolution fixes

* Formatting fixes

* Tests passing

* Block hashes in Graphviz node labels

* Removed unused changes

* Fix bug with states having < SlotsPerHistoricalRoot roots

* Consolidate State/BlockRootsIterator for pruning

* Address review feedback

* Fix a bug in pruning tests

* Detach prune_abandoned_forks() from its object

* Move migrate.rs from store to beacon_chain

* Move forks pruning onto a background thread

* Bugfix: Heads weren't pruned when prune set contained only the head

* Rename: freeze_to_state() -> process_finalization()

* Eliminate redundant function parameter

Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2020-04-20 19:59:56 +10:00
Paul Hauner
2fb6b7c793
Add no-copy block processing cache (#863)
* Add state cache, remove store cache

* Only build the head committee cache

* Fix compile error

* Fix compile error from merge

* Rename state_cache -> checkpoint_cache

* Rename Checkpoint -> Snapshot

* Tidy, add comments

* Tidy up find_head function

* Change some checkpoint -> snapshot

* Add tests

* Expose max_len

* Remove dead code

* Tidy

* Fix bug
2020-04-06 10:53:33 +10:00
Michael Sproul
26bdc2927b
Update to spec v0.11 (#959)
* Update process_final_updates() hysteresis computation

* Update core to v0.11.1

* Bump tags to v0.11.1

* Update docs and deposit contract

* Add compute_fork_digest

* Address review comments

Co-authored-by: Herman Alonso Junge <alonso.junge@gmail.com>
2020-04-01 22:03:03 +11:00
Michael Sproul
6b2e9ff246
Less noisy logs for unaligned finalized blocks (#901) 2020-03-12 12:11:46 +11:00