## Proposed Changes
Cut the first release candidate for v2.0.0, in preparation for testing and release this week
## Additional Info
Builds on #2632, which should either be merged first or in the same batch
## Proposed Changes
Add tooling to lcli to provide a way to measure the attestation packing efficiency of historical blocks by querying a beacon node API endpoint.
## Additional Info
Since block rewards are proportional to the number of unique attestations included in the block, a measure of efficiency can be calculated by comparing the number of unique attestations that could have been included into a block vs the number of unique attestations that were actually included.
This lcli tool provides the following data per block:
- Slot Number
- Proposer Index and Grafitti (if any)
- Available Unique Attestations
- Included Unique Attestations
- Best-effort estimate of the number of offline validators for the epoch. This means we can normalize the calculated efficiency, removing offline validators from the available attestation set.
The data is outputted as a csv file.
## Usage
Install lcli:
```
make install-lcli
```
Alternatively install with the `fake_crypto` feature to skip signature verification which improves performance:
```
cargo install --path lcli --features=fake_crypto --force --locked
```
Ensure a Lighthouse beacon node is running and synced. A non-default API endpoint can be passed with the `--endpoint` flag.
Run:
```
lcli etl-block-efficiency --output /path/to/output.csv --start-epoch 40 --end-epoch 80
```
## Issue Addressed
NA
## Proposed Changes
As `cargo audit` astutely pointed out, the version of `zeroize_derive` were were using had a vulnerability:
```
Crate: zeroize_derive
Version: 1.1.0
Title: `#[zeroize(drop)]` doesn't implement `Drop` for `enum`s
Date: 2021-09-24
ID: RUSTSEC-2021-0115
URL: https://rustsec.org/advisories/RUSTSEC-2021-0115
Solution: Upgrade to >=1.2.0
```
This PR updates `zeroize` and `zeroize_derive` to appease `cargo audit`.
`tiny-bip39` was also updated to allow compile.
## Additional Info
I don't believe this vulnerability actually affected the Lighthouse code-base directly. However, `tiny-bip39` may have been affected which may have resulted in some uncleaned memory in Lighthouse. Whilst this is not ideal, it's not a major issue. Zeroization is a nice-to-have since it only protects from sophisticated attacks or attackers that already have a high level of access already.
## 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.
## Issue Addressed
Closes#1891Closes#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>
# Description
A few changes have been made to discovery. In particular a custom re-write of an LRU cache which previously was read/write O(N) for all our sessions ~5k, to a more reasonable hashmap-style O(1).
Further there has been reported issues in the current discv5, so added error handling to help identify the issue has been added.
[EIP-3030]: https://eips.ethereum.org/EIPS/eip-3030
[Web3Signer]: https://consensys.github.io/web3signer/web3signer-eth2.html
## Issue Addressed
Resolves#2498
## Proposed Changes
Allows the VC to call out to a [Web3Signer] remote signer to obtain signatures.
## Additional Info
### Making Signing Functions `async`
To allow remote signing, I needed to make all the signing functions `async`. This caused a bit of noise where I had to convert iterators into `for` loops.
In `duties_service.rs` there was a particularly tricky case where we couldn't hold a write-lock across an `await`, so I had to first take a read-lock, then grab a write-lock.
### Move Signing from Core Executor
Whilst implementing this feature, I noticed that we signing was happening on the core tokio executor. I suspect this was causing the executor to temporarily lock and occasionally trigger some HTTP timeouts (and potentially SQL pool timeouts, but I can't verify this). Since moving all signing into blocking tokio tasks, I noticed a distinct drop in the "atttestations_http_get" metric on a Prater node:
![http_get_times](https://user-images.githubusercontent.com/6660660/132143737-82fd3836-2e7e-445b-a143-cb347783baad.png)
I think this graph indicates that freeing the core executor allows the VC to operate more smoothly.
### Refactor TaskExecutor
I noticed that the `TaskExecutor::spawn_blocking_handle` function would fail to spawn tasks if it were unable to obtain handles to some metrics (this can happen if the same metric is defined twice). It seemed that a more sensible approach would be to keep spawning tasks, but without metrics. To that end, I refactored the function so that it would still function without metrics. There are no other changes made.
## TODO
- [x] Restructure to support multiple signing methods.
- [x] Add calls to remote signer from VC.
- [x] Documentation
- [x] Test all endpoints
- [x] Test HTTPS certificate
- [x] Allow adding remote signer validators via the API
- [x] Add Altair support via [21.8.1-rc1](https://github.com/ConsenSys/web3signer/releases/tag/21.8.1-rc1)
- [x] Create issue to start using latest version of web3signer. (See #2570)
## Notes
- ~~Web3Signer doesn't yet support the Altair fork for Prater. See https://github.com/ConsenSys/web3signer/issues/423.~~
- ~~There is not yet a release of Web3Signer which supports Altair blocks. See https://github.com/ConsenSys/web3signer/issues/391.~~
## Proposed Changes
This PR deletes all `remote_signer` code from Lighthouse, for the following reasons:
* The `remote_signer` code is unused, and we have no plans to use it now that we're moving to supporting the Web3Signer APIs: #2522
* It represents a significant maintenance burden. The HTTP API tests have been prone to platform-specific failures, and breakages due to dependency upgrades, e.g. #2400.
Although the code is deleted it remains in the Git history should we ever want to recover it. For ease of reference:
- The last commit containing remote signer code: 5a3bcd2904
- The last Lighthouse version: v1.5.1
## Issue Addressed
Resolves#2438Resolves#2437
## Proposed Changes
Changes the permissions for validator client http server api token file and secret key to 600 from 644. Also changes the permission for logfiles generated using the `--logfile` cli option to 600.
Logs the path to the api token instead of the actual api token. Updates docs to reflect the change.
## Issue Addressed
Related to: #2259
Made an attempt at all the necessary updates here to publish the crates to crates.io. I incremented the minor versions on all the crates that have been previously published. We still might run into some issues as we try to publish because I'm not able to test this out but I think it's a good starting point.
## Proposed Changes
- Add description and license to `ssz_types` and `serde_util`
- rename `serde_util` to `eth2_serde_util`
- increment minor versions
- remove path dependencies
- remove patch dependencies
## Additional Info
Crates published:
- [x] `tree_hash` -- need to publish `tree_hash_derive` and `eth2_hashing` first
- [x] `eth2_ssz_types` -- need to publish `eth2_serde_util` first
- [x] `tree_hash_derive`
- [x] `eth2_ssz`
- [x] `eth2_ssz_derive`
- [x] `eth2_serde_util`
- [x] `eth2_hashing`
Co-authored-by: realbigsean <seananderson33@gmail.com>
## Issue Addressed
NA
## Proposed Changes
This PR adds some more fancy macro magic to make it easier to add a new built-in (aka "baked-in") testnet config to the `lighthouse` binary.
Previously, a user needed to modify several files and repeat themselves several times. Now, they only need to add a single definition in the `eth2_config` crate. No repetition 🎉
## 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 🤞
## Issue Addressed
Resolves#2114
Swapped out the ctrlc crate for tokio signals to hook register handlers for SIGPIPE and SIGHUP along with SIGTERM and SIGINT.
## Proposed Changes
- Swap out the ctrlc crate for tokio signals for unix signal handing
- Register signals for SIGPIPE and SHIGUP that trigger the same shutdown procedure as SIGTERM and SIGINT
## Additional Info
I tested these changes against the examples in the original issue and noticed some interesting behavior on my machine. When running `lighthouse bn --network pyrmont |& tee -a pyrmont_bn.log` or `lighthouse bn --network pyrmont 2>&1 | tee -a pyrmont_bn.log` none of the above signals are sent to the lighthouse program in a way I was able to observe.
The only time it seems that the signal gets sent to the lighthouse program is if there is no redirection of stderr to stdout. I'm not as familiar with the details of how unix signals work in linux with a redirect like that so I'm not sure if this is a bug in the program or expected behavior.
Signals are correctly received without the redirection and if the above signals are sent directly to the program with something like `kill`.
## Issue Addressed
NA
## Proposed Changes
- Version bump
- Increase queue sizes for aggregated attestations and re-queued attestations.
## Additional Info
NA
## Proposed Changes
* Consolidate Tokio versions: everything now uses the latest v1.10.0, no more `tokio-compat`.
* Many semver-compatible changes via `cargo update`. Notably this upgrades from the yanked v0.8.0 version of crossbeam-deque which is present in v1.5.0-rc.0
* Many semver incompatible upgrades via `cargo upgrades` and `cargo upgrade --workspace pkg_name`. Notable ommissions:
- Prometheus, to be handled separately: https://github.com/sigp/lighthouse/issues/2485
- `rand`, `rand_xorshift`: the libsecp256k1 package requires 0.7.x, so we'll stick with that for now
- `ethereum-types` is pinned at 0.11.0 because that's what `web3` is using and it seems nice to have just a single version
## Additional Info
We still have two versions of `libp2p-core` due to `discv5` depending on the v0.29.0 release rather than `master`. AFAIK it should be OK to release in this state (cc @AgeManning )
## Issue Addressed
NA
## Proposed Changes
- Bump to `v1.5.0-rc.0`.
- Increase attestation reprocessing queue size (I saw this filling up on Prater).
- Reduce error log for full attn reprocessing queue to warn.
## TODO
- [x] Manual testing
- [x] Resolve https://github.com/sigp/lighthouse/pull/2493
- [x] Include https://github.com/sigp/lighthouse/pull/2501
## Issue Addressed
- Resolves#2457
- Resolves#2443
## Proposed Changes
Target the (presently unreleased) head of `libp2p/rust-libp2p:master` in order to obtain the fix from https://github.com/libp2p/rust-libp2p/pull/2175.
Additionally:
- `libsecp256k1` needed to be upgraded to satisfy the new version of `libp2p`.
- There were also a handful of minor changes to `eth2_libp2p` to suit some interface changes.
- Two `cargo audit --ignore` flags were remove due to libp2p upgrades.
## Additional Info
NA
## Proposed Changes
* Implement the validator client and HTTP API changes necessary to support Altair
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Resolves#2069
## Proposed Changes
- Adds a `--doppelganger-detection` flag
- Adds a `lighthouse/seen_validators` endpoint, which will make it so the lighthouse VC is not interopable with other client beacon nodes if the `--doppelganger-detection` flag is used, but hopefully this will become standardized. Relevant Eth2 API repo issue: https://github.com/ethereum/eth2.0-APIs/issues/64
- If the `--doppelganger-detection` flag is used, the VC will wait until the beacon node is synced, and then wait an additional 2 epochs. The reason for this is to make sure the beacon node is able to subscribe to the subnets our validators should be attesting on. I think an alternative would be to have the beacon node subscribe to all subnets for 2+ epochs on startup by default.
## Additional Info
I'd like to add tests and would appreciate feedback.
TODO: handle validators started via the API, potentially make this default behavior
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
NA
## Proposed Changes
This PR addresses two things:
1. Allows the `ValidatorMonitor` to work with Altair states.
1. Optimizes `altair::process_epoch` (see [code](https://github.com/paulhauner/lighthouse/blob/participation-cache/consensus/state_processing/src/per_epoch_processing/altair/participation_cache.rs) for description)
## Breaking Changes
The breaking changes in this PR revolve around one premise:
*After the Altair fork, it's not longer possible (given only a `BeaconState`) to identify if a validator had *any* attestation included during some epoch. The best we can do is see if that validator made the "timely" source/target/head flags.*
Whilst this seems annoying, it's not actually too bad. Finalization is based upon "timely target" attestations, so that's really the most important thing. Although there's *some* value in knowing if a validator had *any* attestation included, it's far more important to know about "timely target" participation, since this is what affects finality and justification.
For simplicity and consistency, I've also removed the ability to determine if *any* attestation was included from metrics and API endpoints. Now, all Altair and non-Altair states will simply report on the head/target attestations.
The following section details where we've removed fields and provides replacement values.
### Breaking Changes: Prometheus Metrics
Some participation metrics have been removed and replaced. Some were removed since they are no longer relevant to Altair (e.g., total attesting balance) and others replaced with gwei values instead of pre-computed values. This provides more flexibility at display-time (e.g., Grafana).
The following metrics were added as replacements:
- `beacon_participation_prev_epoch_head_attesting_gwei_total`
- `beacon_participation_prev_epoch_target_attesting_gwei_total`
- `beacon_participation_prev_epoch_source_attesting_gwei_total`
- `beacon_participation_prev_epoch_active_gwei_total`
The following metrics were removed:
- `beacon_participation_prev_epoch_attester`
- instead use `beacon_participation_prev_epoch_source_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.
- `beacon_participation_prev_epoch_target_attester`
- instead use `beacon_participation_prev_epoch_target_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.
- `beacon_participation_prev_epoch_head_attester`
- instead use `beacon_participation_prev_epoch_head_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.
The `beacon_participation_prev_epoch_attester` endpoint has been removed. Users should instead use the pre-existing `beacon_participation_prev_epoch_target_attester`.
### Breaking Changes: HTTP API
The `/lighthouse/validator_inclusion/{epoch}/{validator_id}` endpoint loses the following fields:
- `current_epoch_attesting_gwei` (use `current_epoch_target_attesting_gwei` instead)
- `previous_epoch_attesting_gwei` (use `previous_epoch_target_attesting_gwei` instead)
The `/lighthouse/validator_inclusion/{epoch}/{validator_id}` endpoint lose the following fields:
- `is_current_epoch_attester` (use `is_current_epoch_target_attester` instead)
- `is_previous_epoch_attester` (use `is_previous_epoch_target_attester` instead)
- `is_active_in_current_epoch` becomes `is_active_unslashed_in_current_epoch`.
- `is_active_in_previous_epoch` becomes `is_active_unslashed_in_previous_epoch`.
## Additional Info
NA
## TODO
- [x] Deal with total balances
- [x] Update validator_inclusion API
- [ ] Ensure `beacon_participation_prev_epoch_target_attester` and `beacon_participation_prev_epoch_head_attester` work before Altair
Co-authored-by: realbigsean <seananderson33@gmail.com>
* Adjust beacon node timeouts for validator client HTTP requests (#2352)
Resolves#2313
Provide `BeaconNodeHttpClient` with a dedicated `Timeouts` struct.
This will allow granular adjustment of the timeout duration for different calls made from the VC to the BN. These can either be a constant value, or as a ratio of the slot duration.
Improve timeout performance by using these adjusted timeout duration's only whenever a fallback endpoint is available.
Add a CLI flag called `use-long-timeouts` to revert to the old behavior.
Additionally set the default `BeaconNodeHttpClient` timeouts to the be the slot duration of the network, rather than a constant 12 seconds. This will allow it to adjust to different network specifications.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
* Use read_recursive locks in database (#2417)
Closes#2245
Replace all calls to `RwLock::read` in the `store` crate with `RwLock::read_recursive`.
* 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.
* Return more detail when invalid data is found in the DB during startup (#2445)
- Resolves#2444
Adds some more detail to the error message returned when the `BeaconChainBuilder` is unable to access or decode block/state objects during startup.
NA
* Use hardware acceleration for SHA256 (#2426)
Modify the SHA256 implementation in `eth2_hashing` so that it switches between `ring` and `sha2` to take advantage of [x86_64 SHA extensions](https://en.wikipedia.org/wiki/Intel_SHA_extensions). The extensions are available on modern Intel and AMD CPUs, and seem to provide a considerable speed-up: on my Ryzen 5950X it dropped state tree hashing times by about 30% from 35ms to 25ms (on Prater).
The extensions became available in the `sha2` crate [last year](https://www.reddit.com/r/rust/comments/hf2vcx/ann_rustcryptos_sha1_and_sha2_now_support/), and are not available in Ring, which uses a [pure Rust implementation of sha2](https://github.com/briansmith/ring/blob/main/src/digest/sha2.rs). Ring is faster on CPUs that lack the extensions so I've implemented a runtime switch to use `sha2` only when the extensions are available. The runtime switching seems to impose a miniscule penalty (see the benchmarks linked below).
* Start a release checklist (#2270)
NA
Add a checklist to the release draft created by CI. I know @michaelsproul was also working on this and I suspect @realbigsean also might have useful input.
NA
* Serious banning
* fmt
Co-authored-by: Mac L <mjladson@pm.me>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Proposed Changes
Modify the SHA256 implementation in `eth2_hashing` so that it switches between `ring` and `sha2` to take advantage of [x86_64 SHA extensions](https://en.wikipedia.org/wiki/Intel_SHA_extensions). The extensions are available on modern Intel and AMD CPUs, and seem to provide a considerable speed-up: on my Ryzen 5950X it dropped state tree hashing times by about 30% from 35ms to 25ms (on Prater).
## Additional Info
The extensions became available in the `sha2` crate [last year](https://www.reddit.com/r/rust/comments/hf2vcx/ann_rustcryptos_sha1_and_sha2_now_support/), and are not available in Ring, which uses a [pure Rust implementation of sha2](https://github.com/briansmith/ring/blob/main/src/digest/sha2.rs). Ring is faster on CPUs that lack the extensions so I've implemented a runtime switch to use `sha2` only when the extensions are available. The runtime switching seems to impose a miniscule penalty (see the benchmarks linked below).
## 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>
This updates some older dependencies to address a few cargo audit warnings.
The majority of warnings come from network dependencies which will be addressed in #2389.
This PR contains some minor dep updates that are not network related.
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Closes#1661
## Proposed Changes
Add a dummy package called `target_check` which gets compiled early in the build and fails if the target is 32-bit
## Additional Info
You can test the efficacy of this check with:
```
cross build --release --manifest-path lighthouse/Cargo.toml --target i686-unknown-linux-gnu
```
In which case this compilation error is shown:
```
error: Lighthouse requires a 64-bit CPU and operating system
--> common/target_check/src/lib.rs:8:1
|
8 | / assert_cfg!(
9 | | target_pointer_width = "64",
10 | | "Lighthouse requires a 64-bit CPU and operating system",
11 | | );
| |__^
```
## Issue Addressed
Closes#2354
## Proposed Changes
Add a `minify` method to `slashing_protection::Interchange` that keeps only the maximum-epoch attestation and maximum-slot block for each validator. Specifically, `minify` constructs "synthetic" attestations (with no `signing_root`) containing the maximum source epoch _and_ the maximum target epoch from the input. This is equivalent to the `minify_synth` algorithm that I've formally verified in this repository:
https://github.com/michaelsproul/slashing-proofs
## Additional Info
Includes the JSON loading optimisation from #2347
## Issue Addressed
NA
## Proposed Changes
I've noticed some of the SigP Prater nodes struggling on v1.4.0-rc.0. I suspect this is due to the changes in #2296. Specifically, the trade-off which lowered the memory footprint whilst increasing runtime on some functions.
Presently, this PR is documenting my testing on Prater.
## Additional Info
NA
## Issue Addressed
NA
## Proposed Changes
Bump versions.
## Additional Info
This is not exactly the v1.4.0 release described in [Lighthouse Update #36](https://lighthouse.sigmaprime.io/update-36.html).
Whilst it contains:
- Beta Windows support
- A reduction in Eth1 queries
- A reduction in memory footprint
It does not contain:
- Altair
- Doppelganger Protection
- The remote signer
We have decided to release some features early. This is primarily due to the desire to allow users to benefit from the memory saving improvements as soon as possible.
## TODO
- [x] Wait for #2340, #2356 and #2376 to merge and then rebase on `unstable`.
- [x] Ensure discovery issues are fixed (see #2388)
- [x] Ensure https://github.com/sigp/lighthouse/pull/2382 is merged/removed.
- [x] Ensure https://github.com/sigp/lighthouse/pull/2383 is merged/removed.
- [x] Ensure https://github.com/sigp/lighthouse/pull/2384 is merged/removed.
- [ ] Double-check eth1 cache is carried between boots
## Issue Addressed
NA
## Proposed Changes
Reverts #2345 in the interests of getting v1.4.0 out this week. Once we have released that, we can go back to testing this again.
## Additional Info
NA
The ordering of adding new peers to the peerdb and deciding when to dial them was not considered in a previous update.
This adds the condition that if a peer is not in the peer-db then it is an acceptable peer to dial.
This makes #2374 obsolete.