Commit Graph

1332 Commits

Author SHA1 Message Date
Age Manning
28b6d921c6 Remove banned peers from DHT and track IPs (#1656)
## Issue Addressed

#629 

## Proposed Changes

This removes banned peers from the DHT and informs discovery to block the node_id and the known source IP's associated with this node. It has the capabilities of un banning this peer after a period of time. 

This also corrects the logic about banning specific IP addresses. We now use seen_ip addresses from libp2p rather than those sent to us via identify (which also include local addresses).
2020-09-25 01:52:39 +00:00
Pawan Dhananjay
15638d1448 Beacon node does not quit on eth1 errors (#1663)
## Issue Addressed

N/A

## Proposed Changes

Log critical errors instead of quitting if eth1 node cannot be reached or is on wrong network id.
2020-09-25 00:43:45 +00:00
divma
b8013b7b2c Super Silky Smooth Syncs, like a Sir (#1628)
## Issue Addressed
In principle.. closes #1551 but in general are improvements for performance, maintainability and readability. The logic for the optimistic sync in actually simple

## Proposed Changes
There are miscellaneous things here:
- Remove unnecessary `BatchProcessResult::Partial` to simplify the batch validation logic
- Make batches a state machine. This is done to ensure batch state transitions respect our logic (this was previously done by moving batches between `Vec`s) and to ease the cognitive load of the `SyncingChain` struct
- Move most batch-related logic to the batch
- Remove `PendingBatches` in favor of a map of peers to their batches. This is to avoid duplicating peers inside the chain (peer_pool and pending_batches)
- Add `must_use` decoration to the `ProcessingResult` so that chains that request to be removed are handled accordingly. This also means that chains are now removed in more places than before to account for unhandled cases
- Store batches in a sorted map (`BTreeMap`) access is not O(1) but since the number of _active_ batches is bounded this should be fast, and saves performing hashing ops. Batches are indexed by the epoch they start. Sorted, to easily handle chain advancements (range logic)
- Produce the chain Id from the identifying fields: target root and target slot. This, to guarantee there can't be duplicated chains and be able to consistently search chains by either Id or checkpoint
- Fix chain_id not being present in all chain loggers
- Handle mega-edge case where the processor's work queue is full and the batch can't be sent. In this case the chain would lose the blocks, remain in a "syncing" state and waiting for a result that won't arrive, effectively stalling sync.
- When a batch imports blocks or the chain starts syncing with a local finalized epoch greater that the chain's start epoch, the chain is advanced instead of reset. This is to avoid losing download progress and validate batches faster. This also means that the old `start_epoch` now means "current first unvalidated batch", so it represents more accurately the progress of the chain.
- Batch status peers from the same chain to reduce Arc access.
- Handle a couple of cases where the retry counters for a batch were not updated/checked are now handled via the batch state machine. Basically now if we forget to do it, we will know.
- Do not send back the blocks from the processor to the batch. Instead register the attempt before sending the blocks (does not count as failed)
- When re-requesting a batch, try to avoid not only the last failed peer, but all previous failed peers.
- Optimize requesting batches ahead in the buffer by shuffling idle peers just once (this is just addressing a couple of old TODOs in the code)
- In chain_collection, store chains by their id in a map
- Include a mapping from request_ids to (chain, batch) that requested the batch to avoid the double O(n) search on block responses
- Other stuff:
  - impl `slog::KV` for batches
  - impl `slog::KV` for syncing chains
  - PSA: when logging, we can use `%thing` if `thing` implements `Display`. Same for `?` and `Debug`

### Optimistic syncing:
Try first the batch that contains the current head, if the batch imports any block, advance the chain. If not, if this optimistic batch is inside the current processing window leave it there for future use, if not drop it. The tolerance for this block is the same for downloading, but just once for processing



Co-authored-by: Age Manning <Age@AgeManning.com>
2020-09-23 06:29:55 +00:00
Age Manning
80e52a0263 Subscribe to core topics after sync (#1613)
## Issue Addressed

N/A

## Proposed Changes

Prevent subscribing to core gossipsub topics until after we have achieved a full sync. This prevents us censoring gossipsub channels, getting penalised in gossipsub 1.1 scoring and saves us computation time in attempting to validate gossipsub messages which we will be unable to do with a non-sync'd chain.
2020-09-23 03:26:33 +00:00
Pawan Dhananjay
80ecafaae4 Add --staking flag (#1641)
## Issue Addressed

Closes #1472 

## Proposed Changes

Add `--staking` ~~and`staking-with-eth1-endpoint`~~ flag to improve UX for stakers.


Co-authored-by: Paul Hauner <paul@paulhauner.com>
2020-09-23 01:19:58 +00:00
realbigsean
b75df29501 minimize the number of places we are calling update_pubkey_cache (#1626)
## Issue Addressed

- Resolves #1080

## Proposed Changes

- Call `update_pubkey_cache` only in the `build_all_caches` method and `get_validator_index` method. 

## Additional Info

This does reduce the number of places the cache is updated, making it simpler. But the `get_validator_index` method is used a couple times when we are iterating through the entire validator registry (or set of active validators). Before, we would only call `update_pubkey_cache` once before iterating through all validators.  So I'm not _totally_ sure this change is worth it.
2020-09-23 01:19:56 +00:00
Pawan Dhananjay
a97ec318c4 Subscribe to subnets an epoch in advance (#1600)
## Issue Addressed

N/A

## Proposed Changes

Subscibe to subnet an epoch in advance of the attestation slot instead of 4 slots in advance.
2020-09-22 07:29:34 +00:00
Paul Hauner
d85d5a435e Bump to v0.2.11 (#1645)
## Issue Addressed

NA

## Proposed Changes

- Bump version to v0.2.11
- Run `cargo update`.


## Additional Info

NA
2020-09-22 04:45:15 +00:00
Paul Hauner
bd39cc8e26 Apply hotfix for inconsistent head (#1639)
## Issue Addressed

- Resolves #1616

## Proposed Changes

If we look at the function which persists fork choice and the canonical head to disk:

1db8daae0c/beacon_node/beacon_chain/src/beacon_chain.rs (L234-L280)

There is a race-condition which might cause the canonical head and fork choice values to be out-of-sync.

I believe this is the cause of #1616. I managed to recreate the issue and produce a database that was unable to sync under the `master` branch but able to sync with this branch.

These new changes solve the issue by ignoring the persisted `canonical_head_block_root` value and instead getting fork choice to generate it. This ensures that the canonical head is in-sync with fork choice.

## Additional Info

This is hotfix method that leaves some crusty code hanging around. Once this PR is merged (to satisfy the v0.2.x users) we should later update and merge #1638 so we can have a clean fix for the v0.3.x versions.
2020-09-22 02:06:10 +00:00
Pawan Dhananjay
14ff38539c Add trusted peers (#1640)
## Issue Addressed

Closes #1581 

## Proposed Changes

Adds a new cli option for trusted peers who always have the maximum possible score.
2020-09-22 01:12:36 +00:00
Michael Sproul
5d17eb899f Update LevelDB to v0.8.6, removing patch (#1636)
Removes our dependency on a fork of LevelDB now that https://github.com/skade/leveldb-sys/pull/17 is merged
2020-09-21 11:53:53 +00:00
Age Manning
1db8daae0c Shift metadata to the global network variables (#1631)
## Issue Addressed

N/A

## Proposed Changes

Shifts the local `metadata` to `network_globals` making it accessible to the HTTP API and other areas of lighthouse.

## Additional Info

N/A
2020-09-21 02:00:38 +00:00
Pawan Dhananjay
7b97c4ad30 Snappy additional sanity checks (#1625)
## Issue Addressed

N/A

## Proposed Changes

Adds the following check from the spec

> A reader SHOULD NOT read more than max_encoded_len(n) bytes after reading the SSZ length-prefix n from the header.
2020-09-21 01:06:25 +00:00
Paul Hauner
371e1c1d5d Bump version to v0.2.10 (#1630)
## Issue Addressed

NA

## Proposed Changes

Bump crate version so we can cut a new release with the fix from #1629.

## Additional Info

NA
2020-09-18 06:41:29 +00:00
Paul Hauner
a17f74896a Fix bad assumption when checking finalized descendant (#1629)
## Issue Addressed

- Resolves #1616

## Proposed Changes

Fixes a bug where we are unable to read the finalized block from fork choice.

## Detail

I had made an assumption that the finalized block always has a parent root of `None`:

e5fc6bab48/consensus/fork_choice/src/fork_choice.rs (L749-L752)

This was a faulty assumption, we don't set parent *roots* to `None`. Instead we *sometimes* set parent *indices* to `None`, depending if this pruning condition is satisfied: 

e5fc6bab48/consensus/proto_array/src/proto_array.rs (L229-L232) 

The bug manifested itself like this:

1. We attempt to get the finalized block from fork choice
1. We try to check that the block is descendant of the finalized block (note: they're the same block).
1. We expect the parent root to be `None`, but it's actually the parent root of the finalized root.
1. We therefore end up checking if the parent of the finalized root is a descendant of itself. (note: it's an *ancestor* not a *descendant*).
1. We therefore declare that the finalized block is not a descendant of (or eq to) the finalized block. Bad.

## Additional Info

In reflection, I made a poor assumption in the quest to obtain a probably negligible performance gain. The performance gain wasn't worth the risk and we got burnt.
2020-09-18 05:14:31 +00:00
Age Manning
49ab414594 Shift gossipsub validation (#1612)
## Issue Addressed

N/A

## Proposed Changes

This will consider all gossipsub messages that have either the `from`, `seqno` or `signature` field as invalid. 

## Additional Info

We should not merge this until all other clients have been sending empty fields for a while.

See https://github.com/ethereum/eth2.0-specs/issues/1981 for reference
2020-09-18 02:05:36 +00:00
Age Manning
2074beccdc Gossipsub message id to shortened bytes (#1607)
## Issue Addressed

https://github.com/ethereum/eth2.0-specs/pull/2044

## Proposed Changes

Shifts the gossipsub message id to use the first 8 bytes of the SHA256 hash of the gossipsub message data field.

## Additional Info

We should merge this in once the spec has been decided on. It will cause issues with gossipsub scoring and gossipsub propagation rates (as we won't receive IWANT) messages from clients that also haven't made this update.
2020-09-18 02:05:34 +00:00
Age Manning
c9596fcf0e Temporary Sync Work-Around (#1615)
## Issue Addressed

#1590 

## Proposed Changes

This is a temporary workaround that prevents finalized chain sync from swapping chains. I'm merging this in now until the full solution is ready.
2020-09-13 23:58:49 +00:00
Age Manning
c6abc56113 Prevent large step-size parameters (#1583)
## Issue Addressed

Malicious users could request very large block ranges, more than we expect. Although technically legal, we are now quadraticaly weighting large step sizes in the filter. Therefore users may request large skips, but not a large number of blocks, to prevent requests forcing us to do long chain lookups. 

## Proposed Changes

Weight the step parameter in the RPC filter and prevent any overflows that effect us in the step parameter.

## Additional Info
2020-09-11 02:33:36 +00:00
blacktemplar
7f1b936905 ignore too early / too late attestations instead of penalizing them (#1608)
## Issue Addressed

NA

## Proposed Changes

This ignores attestations that are too early or too late as it is specified in the spec (see https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/p2p-interface.md#global-topics first subpoint of `beacon_aggregate_and_proof`)
2020-09-11 01:43:15 +00:00
Pawan Dhananjay
0525876882 Dial cached enr's before making subnet discovery query (#1376)
## Issue Addressed

Closes #1365 

## Proposed Changes

Dial peers in the `cached_enrs` who aren't connected, aren't banned and satisfy the subnet predicate before making a subnet discovery query.
2020-09-11 00:52:27 +00:00
Age Manning
d79366c503 Prevent printing binary in RPC errors (#1604)
## Issue Addressed

#1566 

## Proposed Changes

Prevents printing binary characters in the RPC error response from peers.
2020-09-10 04:43:22 +00:00
Age Manning
b19cf02d2d Penalise bad peer behaviour (#1602)
## Issue Addressed

#1386 

## Proposed Changes

Penalises peers in our scoring system that produce invalid attestations or blocks.
2020-09-10 03:51:06 +00:00
Paul Hauner
0821e6b39f Bump version to v0.2.9 (#1598)
## Issue Addressed

NA

## Proposed Changes

- Bump version tags
- Run `cargo update`

## Additional Info

NA
2020-09-09 02:28:35 +00:00
Pawan Dhananjay
00cdc4bb35 Update state before producing attestation (#1596)
## Issue Addressed

Partly addresses #1547 

## Proposed Changes

This fix addresses the missing attestations at slot 0 of an epoch (also sometimes slot 1 when slot 0 was skipped).
There are 2 cases:
1. BN receives the block for the attestation slot after 4 seconds (1/3rd of the slot).
2. No block is proposed for this slot.

In both cases, when we produce the attestation, we pass the head state to the 
`produce_unaggregated_attestation_for_block` function here
9833eca024/beacon_node/beacon_chain/src/beacon_chain.rs (L845-L850)

Since we don't advance the state in this function, we set `attestation.data.source = state.current_justified_checkpoint` which is atleast 2 epochs lower than current_epoch(wall clock epoch). 
This attestation is invalid and cannot be included in a block because of this assert from the spec:
```python
if data.target.epoch == get_current_epoch(state):
        assert data.source == state.current_justified_checkpoint
        state.current_epoch_attestations.append(pending_attestation)
```
https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#attestations

This PR changes the `produce_unaggregated_attestation_for_block` function to ensure that it advances the state before producing the attestation at the new epoch.

Running this on my node, have missed 0 attestations across all 8 of my validators in a 100 epoch period 🎉 
To compare, I was missing ~14 attestations across all 8 validators in the same 100 epoch period before the fix. 

Will report missed attestations if any after running for another 100 epochs tomorrow.
2020-09-08 11:25:43 +00:00
Daniel Schonfeld
2a9a815f29 conforming to the p2p specs, requiring error_messages to be bound (#1593)
## Issue Addressed

#1421 

## Proposed Changes

Bounding the error_message that can be returned for RPC domain errors


Co-authored-by: Age Manning <Age@AgeManning.com>
2020-09-07 06:47:05 +00:00
Age Manning
a6376b4585 Update discv5 to v10 (#1592)
## Issue Addressed

Code improvements, dependency improvements and better async handling.
2020-09-07 05:53:20 +00:00
Sean
638daa87fe Avoid Printing Binary String to Logs (#1576)
Converts the graffiti binary data to string before printing to logs.

## Issue Addressed

#1566 

## Proposed Changes
Rather than converting graffiti to a vector the binary data less the last character is passed to String::from_utf_lossy(). This then allows us to call the to_string() function directly to give us the string

## Additional Info

Rust skills are fairly weak
2020-09-05 05:46:25 +00:00
Age Manning
fb9d828e5e Extended Gossipsub metrics (#1577)
## Issue Addressed

N/A

## Proposed Changes

Adds extended metrics to get a better idea of what is happening at the gossipsub layer of lighthouse. This provides information about mesh statistics per topics, subscriptions and peer scores. 

## Additional Info
2020-09-01 06:59:14 +00:00
Pawan Dhananjay
adea7992f8 Eth1 network exit on wrong network id (#1563)
## Issue Addressed

Fixes #1509 

## Proposed Changes

Exit the beacon node if the eth1 endpoint points to an invalid eth1 network. Check the network id before every eth1 cache update and display an error log if the network id has changed to an invalid one.
2020-08-31 02:36:17 +00:00
blacktemplar
c18d37c202 Use Gossipsub 1.1 (#1516)
## Issue Addressed

#1172

## Proposed Changes

* updates the libp2p dependency
* small adaptions based on changes in libp2p
* report not just valid messages but also invalid and distinguish between `IGNORE`d messages and `REJECT`ed messages


Co-authored-by: Age Manning <Age@AgeManning.com>
2020-08-30 13:06:50 +00:00
Paul Hauner
967700c1ff Bump version to v0.2.8 (#1572)
## Issue Addressed

NA

## Proposed Changes

- Bump versions
- Run `cargo update`

## Additional Info

NA
2020-08-27 07:04:12 +00:00
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
dfd02d6179 Bump to v0.2.7 (#1561)
## Issue Addressed

NA

## Proposed Changes

- Update to v0.2.7
- Add script to make update easy.

## Additional Info

NA
2020-08-24 08:25:34 +00:00
Paul Hauner
3569506acd Remove rayon from rest_api (#1562)
## Issue Addressed

NA

## Proposed Changes

Addresses a deadlock condition described here: https://hackmd.io/ijQlqOdqSGaWmIo6zMVV-A?view

## Additional Info

NA
2020-08-24 07:28:54 +00:00
Paul Hauner
c895dc8971 Shift HTTP server heavy-lifting to blocking executor (#1518)
## Issue Addressed

NA

## Proposed Changes

Shift practically all HTTP endpoint handlers to the blocking executor (some very light tasks are left on the core executor).

## Additional Info

This PR covers the `rest_api` which will soon be refactored to suit the standard API. As such, I've cut a few corners and left some existing issues open in this patch. What I have done here should leave the API in state that is not necessary *exactly* the same, but good enough for us to run validators with. Specifically, the number of blocking workers that can be spawned is unbounded and I have not implemented a queue; this will need to be fixed when we implement the standard API.
2020-08-24 03:06:10 +00:00
blacktemplar
2bc9115a94 reuse beacon_node methods for initializing network configs in boot_node (#1520)
## Issue Addressed

#1378

## Proposed Changes

Boot node reuses code from beacon_node to initialize network config. This also enables using the network directory to store/load the enr and the private key.

## Additional Info

Note that before this PR the port cli arguments were off (the argument was named `enr-port` but used as `boot-node-enr-port`).
Therefore as port always the cli port argument was used (for both enr and listening). Now the enr-port argument can be used to overwrite the listening port as the public port others should connect to.

Last but not least note, that this restructuring reuses `ethlibp2p::NetworkConfig` that has many more options than the ones used in the boot node. For example the network config has an own `discv5_config` field that gets never used in the boot node and instead another `Discv5Config` gets created later in the boot node process.

Co-authored-by: Age Manning <Age@AgeManning.com>
2020-08-21 12:00:01 +00:00
blacktemplar
3f0a113c7f ban IP addresses if too many banned peers for this IP address (#1543)
## Issue Addressed

#1283 

## Proposed Changes

All peers with the same IP will be considered banned as long as there are more than 5 (constant) peers with this IP that have a score below the ban threshold. As soon as some of those 5 peers get unbanned (through decay) and if there are then less than 5 peers with a score below the threshold the IP will be considered not banned anymore.
2020-08-21 01:41:12 +00:00
Paul Hauner
ebb25b5569 Bump version to v0.2.6 (#1549)
## Issue Addressed

NA

## Proposed Changes

See title.

## Additional Info

NA
2020-08-19 09:31:01 +00:00
Pawan Dhananjay
bbed42f30c Refactor attestation service (#1415)
## Issue Addressed

N/A

## Proposed Changes

Refactor attestation service to send out requests to find peers for subnets as soon as we get attestation duties. 
Earlier, we had much more involved logic to send the discovery requests to the discovery service only 6 slots before the attestation slot. Now that discovery is much smarter with grouped queries, the complexity in attestation service can be reduced considerably.



Co-authored-by: Age Manning <Age@AgeManning.com>
2020-08-19 08:46:25 +00:00
divma
fdc6e2aa8e Shutdown like a Sir (#1545)
## Issue Addressed
#1494 

## Proposed Changes
- Give the TaskExecutor the sender side of a channel that a task can clone to request shutting down
- The receiver side of this channel is in environment and now we block until ctrl+c or an internal shutdown signal is received
- The swarm now informs when it has reached 0 listeners
- The network receives this message and requests the shutdown
2020-08-19 05:51:14 +00:00
Paul Hauner
8e7dd7b2b1 Add remaining network ops to queuing system (#1546)
## Issue Addressed

NA

## Proposed Changes

- Refactors the `BeaconProcessor` to remove some excessive nesting and file bloat
  - Sorry about the noise from this, it's all contained in 4d3f8c5 though.
- Adds exits, proposer slashings, attester slashings to the `BeaconProcessor` so we don't get overwhelmed with large amounts of slashings (which happened a few hours ago).

## Additional Info

NA
2020-08-19 05:09:53 +00:00
Age Manning
33b2a3d0e0 Version bump to v0.2.5 (#1540)
## Description

Version bumps lighthouse to v0.2.5
2020-08-18 11:23:08 +00:00
Paul Hauner
93b7c3b7ff Set default max skips to 700 (#1542)
## Issue Addressed

NA

## Proposed Changes

Sets the default max skips to 700 so that it can cover the 693 slot skip from `80894 - 80201`.

## Additional Info

NA
2020-08-18 09:27:04 +00:00
Age Manning
2d0b214b57 Clean up logs (#1541)
## Description

This PR improves some logging for the end-user. 

It downgrades some warning logs and removes the slots per second sync speed if we are syncing and the speed is 0. This is likely because we are syncing from a finalised checkpoint and the head doesn't change.
2020-08-18 08:11:39 +00:00
Paul Hauner
d4f763bbae Fix mistake with attestation skip slots (#1539)
## Issue Addressed

NA

## Proposed Changes

- Fixes a mistake I made in #1530 which resulted us in *not* rejecting attestations that we intended to reject.
- Adds skip-slot checks for blocks earlier in import process, so it rejects gossip and RPC blocks.

## Additional Info

NA
2020-08-18 06:28:26 +00:00
Age Manning
e1e5002d3c Fingerprint Lodestar (#1536)
Fingerprints the Lodestar client
2020-08-18 06:28:24 +00:00
Age Manning
8311074d68 Purge out-dated head chains on chain completion (#1538)
## Description

There can be many head chains queued up to complete. Currently we try and process all of these to completion before we consider the node synced. 

In a chaotic network, there can be many of these and processing them to completion can be very expensive and slow. This PR removes any non-syncing head chains from the queue, and re-status's the peers. If, after we have synced to head on one chain, there is still a valid head chain to download, it will be re-established once the status has been returned. 

This should assist with getting nodes to sync on medalla faster.
2020-08-18 05:22:34 +00:00
Age Manning
3bb30754d9 Keep track of failed head chains and prevent re-lookups (#1534)
## Overview

There are forked chains which get referenced by blocks and attestations on a network. Typically if these chains are very long, we stop looking up the chain and downvote the peer. In extreme circumstances, many peers are on many chains, the chains can be very deep and become time consuming performing lookups. 

This PR adds a cache to known failed chain lookups. This prevents us from starting a parent-lookup (or stopping one half way through) if we have attempted the chain lookup in the past.
2020-08-18 03:54:09 +00:00