## 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>
## 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>
## 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
## 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.
## 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.
## 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.
The changes are somewhat simple but should solve two issues:
- When quickly changing between chains once and a second time back again, batchIds would collide and cause havoc.
- If we got an out of range response from a peer, sync would remain in syncing but without advancing
Changes:
- remove the batch id. Identify each batch (inside a chain) by its starting epoch. Target epochs for downloading and processing now advance by EPOCHS_PER_BATCH
- for the same reason, move the "to_be_downloaded_id" to be an epoch
- remove a sneaky line that dropped an out of range batch without downloading it
- bonus: put the chain_id in the log given to the chain. This is why explicitly logging the chain_id is removed
## Proposed Changes
To mitigate the impact of minority forks on RAM and disk usage, this change rejects blocks whose parent lies more than 320 slots (10 epochs, ~1 hour) in the past. The behaviour is configurable via `lighthouse bn --max-skip-slots N`, and can be turned off entirely using `--max-skip-slots none`.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
NA
## Proposed Changes
Moves beacon block processing over to the newly-added `GossipProcessor`. This moves the task off the core executor onto the blocking one.
## Additional Info
- With this PR, gossip blocks are being ignored during sync.
