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
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src	Rate limiting backfill sync (#3936)	2023-04-03 03:02:55 +00:00
Cargo.toml	Update and consolidate dependencies (#3136)	2022-04-04 00:26:16 +00:00