lighthouse-pulse/lighthouse/tests
Jimmy Chen 2de3451011 Rate limiting backfill sync (#3936)
## Issue Addressed

#3212 

## Proposed Changes

- Introduce a new `rate_limiting_backfill_queue` - any new inbound backfill work events gets immediately sent to this FIFO queue **without any processing**
- Spawn a `backfill_scheduler` routine that pops a backfill event from the FIFO queue at specified intervals (currently halfway through a slot, or at 6s after slot start for 12s slots) and sends the event to `BeaconProcessor` via a `scheduled_backfill_work_tx` channel
- This channel gets polled last in the `InboundEvents`, and work event received is  wrapped in a `InboundEvent::ScheduledBackfillWork` enum variant, which gets processed immediately or queued by the `BeaconProcessor` (existing logic applies from here)

Diagram comparing backfill processing with / without rate-limiting: 
https://github.com/sigp/lighthouse/issues/3212#issuecomment-1386249922

See this comment for @paulhauner's  explanation and solution: https://github.com/sigp/lighthouse/issues/3212#issuecomment-1384674956

## Additional Info

I've compared this branch (with backfill processing rate limited to to 1 and 3 batches per slot) against the latest stable version. The CPU usage during backfill sync is reduced by ~5% - 20%, more details on this page:

https://hackmd.io/@jimmygchen/SJuVpJL3j

The above testing is done on Goerli (as I don't currently have hardware for Mainnet), I'm guessing the differences are likely to be bigger on mainnet due to block size.

### TODOs

- [x] Experiment with processing multiple batches per slot. (need to think about how to do this for different slot durations)
- [x] Add option to disable rate-limiting, enabed by default.
- [x] (No longer required now we're reusing the reprocessing queue) Complete the `backfill_scheduler` task when backfill sync is completed or not required
2023-04-03 03:02:55 +00:00
..
account_manager.rs Builder Specs v0.2.0 (#3134) 2022-07-30 00:22:37 +00:00
beacon_node.rs Rate limiting backfill sync (#3936) 2023-04-03 03:02:55 +00:00
boot_node.rs Support for Ipv6 (#4046) 2023-03-14 01:13:34 +00:00
exec.rs Enforce Optimistic Sync Conditions & CLI Tests (v2) (#3050) 2022-03-01 22:56:47 +00:00
main.rs Add regression tests for boot_node (#2749) 2021-11-08 01:37:58 +00:00
validator_client.rs Add latency measurement service to VC (#4024) 2023-03-05 23:43:29 +00:00