Part of #7866
- Continuation of #7921
In the above PR, we enabled rayon for batch KZG verification in chain segment processing. However, using the global rayon thread pool for backfill is likely to create resource contention with higher-priority beacon processor work.
This PR introduces a dedicated low-priority rayon thread pool `LOW_PRIORITY_RAYON_POOL` and uses it for processing backfill chain segments.
This prevents backfill KZG verification from using the global rayon thread pool and competing with high-priority beacon processor tasks for CPU resources.
However, this PR by itself doesn't prevent CPU oversubscription because other tasks could still fill up the global rayon thread pool, and having an extra thread pool could make things worse. To address this we need the beacon
processor to coordinate total CPU allocation across all tasks, which is covered in:
- #7789
Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>
Co-Authored-By: Eitan Seri- Levi <eserilev@gmail.com>
Co-Authored-By: Eitan Seri-Levi <eserilev@ucsc.edu>
* Fix stuck backfill and add regression test.
* Remove unnecessary `yield_now`
* Merge branch 'unstable' into fix-stuck-backfill
* Revert previous change and add extra comment.
* Merge branch 'unstable' into fix-stuck-backfill
* Update tests to use configured event schedule instead of hard coded values.
* Merge branch 'unstable' of https://github.com/sigp/lighthouse into fix-stuck-backfill
## Issue Addressed
Synchronize dependencies and edition on the workspace `Cargo.toml`
## Proposed Changes
with https://github.com/rust-lang/cargo/issues/8415 merged it's now possible to synchronize details on the workspace `Cargo.toml` like the metadata and dependencies.
By only having dependencies that are shared between multiple crates aligned on the workspace `Cargo.toml` it's easier to not miss duplicate versions of the same dependency and therefore ease on the compile times.
## Additional Info
this PR also removes the no longer required direct dependency of the `serde_derive` crate.
should be reviewed after https://github.com/sigp/lighthouse/pull/4639 get's merged.
closes https://github.com/sigp/lighthouse/issues/4651
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
NA
## Proposed Changes
Rather than spawning new tasks on the tokio executor to process each HTTP API request, send the tasks to the `BeaconProcessor`. This achieves:
1. Places a bound on how many concurrent requests are being served (i.e., how many we are actually trying to compute at one time).
1. Places a bound on how many requests can be awaiting a response at one time (i.e., starts dropping requests when we have too many queued).
1. Allows the BN prioritise HTTP requests with respect to messages coming from the P2P network (i.e., proiritise importing gossip blocks rather than serving API requests).
Presently there are two levels of priorities:
- `Priority::P0`
- The beacon processor will prioritise these above everything other than importing new blocks.
- Roughly all validator-sensitive endpoints.
- `Priority::P1`
- The beacon processor will prioritise practically all other P2P messages over these, except for historical backfill things.
- Everything that's not `Priority::P0`
The `--http-enable-beacon-processor false` flag can be supplied to revert back to the old behaviour of spawning new `tokio` tasks for each request:
```
--http-enable-beacon-processor <BOOLEAN>
The beacon processor is a scheduler which provides quality-of-service and DoS protection. When set to
"true", HTTP API requests will queued and scheduled alongside other tasks. When set to "false", HTTP API
responses will be executed immediately. [default: true]
```
## New CLI Flags
I added some other new CLI flags:
```
--beacon-processor-aggregate-batch-size <INTEGER>
Specifies the number of gossip aggregate attestations in a signature verification batch. Higher values may
reduce CPU usage in a healthy network while lower values may increase CPU usage in an unhealthy or hostile
network. [default: 64]
--beacon-processor-attestation-batch-size <INTEGER>
Specifies the number of gossip attestations in a signature verification batch. Higher values may reduce CPU
usage in a healthy network whilst lower values may increase CPU usage in an unhealthy or hostile network.
[default: 64]
--beacon-processor-max-workers <INTEGER>
Specifies the maximum concurrent tasks for the task scheduler. Increasing this value may increase resource
consumption. Reducing the value may result in decreased resource usage and diminished performance. The
default value is the number of logical CPU cores on the host.
--beacon-processor-reprocess-queue-len <INTEGER>
Specifies the length of the queue for messages requiring delayed processing. Higher values may prevent
messages from being dropped while lower values may help protect the node from becoming overwhelmed.
[default: 12288]
```
I needed to add the max-workers flag since the "simulator" flavor tests started failing with HTTP timeouts on the test assertions. I believe they were failing because the Github runners only have 2 cores and there just weren't enough workers available to process our requests in time. I added the other flags since they seem fun to fiddle with.
## Additional Info
I bumped the timeouts on the "simulator" flavor test from 4s to 8s. The prioritisation of consensus messages seems to be causing slower responses, I guess this is what we signed up for 🤷
The `validator/register` validator has some special handling because the relays have a bad habit of timing out on these calls. It seems like a waste of a `BeaconProcessor` worker to just wait for the builder API HTTP response, so we spawn a new `tokio` task to wait for a builder response.
I've added an optimisation for the `GET beacon/states/{state_id}/validators/{validator_id}` endpoint in [efbabe3](efbabe3252). That's the endpoint the VC uses to resolve pubkeys to validator indices, and it's the endpoint that was causing us grief. Perhaps I should move that into a new PR, not sure.
*Replaces #4434. It is identical, but this PR has a smaller diff due to a curated commit history.*
## Issue Addressed
NA
## Proposed Changes
This PR moves the scheduling logic for the `BeaconProcessor` into a new crate in `beacon_node/beacon_processor`. Previously it existed in the `beacon_node/network` crate.
This addresses a circular-dependency problem where it's not possible to use the `BeaconProcessor` from the `beacon_chain` crate. The `network` crate depends on the `beacon_chain` crate (`network -> beacon_chain`), but importing the `BeaconProcessor` into the `beacon_chain` crate would create a circular dependancy of `beacon_chain -> network`.
The `BeaconProcessor` was designed to provide queuing and prioritized scheduling for messages from the network. It has proven to be quite valuable and I believe we'd make Lighthouse more stable and effective by using it elsewhere. In particular, I think we should use the `BeaconProcessor` for:
1. HTTP API requests.
1. Scheduled tasks in the `BeaconChain` (e.g., state advance).
Using the `BeaconProcessor` for these tasks would help prevent the BN from becoming overwhelmed and would also help it to prioritize operations (e.g., choosing to process blocks from gossip before responding to low-priority HTTP API requests).
## Additional Info
This PR is intended to have zero impact on runtime behaviour. It aims to simply separate the *scheduling* code (i.e., the `BeaconProcessor`) from the *business logic* in the `network` crate (i.e., the `Worker` impls). Future PRs (see #4462) can build upon these works to actually use the `BeaconProcessor` for more operations.
I've gone to some effort to use `git mv` to make the diff look more like "file was moved and modified" rather than "file was deleted and a new one added". This should reduce review burden and help maintain commit attribution.
