Demote Paraswap Errors to warn! + success/failure metrics

[bh2smith]

Based on the amount of noise produced by Paraswap errors in our alerts channel, we deemed it appropriate to demote these errors to warnings and instead record success/failure counts of the single order solver grouped by solver name.

Note that this change required passing Arc<dyn SolverMetrics> through the trait method Solver::solve which remains unused in many places (apart from the single order solver). However, this PR serves as a good preparation for recording other metrics to come (refined time counters on different stages of solving, etc...).

Test Plan

I recall that @fleupold had done some sort of manual test for metrics at one point and provided the result data in some strange prometheus file format. I could do that if it seems appropriate.

1. Run the solver locally pointed at the production orderbook with just the Paraswap solver enabled

2. Connect to the metrics api and find something like this in the logs

# HELP gp_v2_solver_single_order_solver Success/Failure counts
# TYPE gp_v2_solver_single_order_solver counter
gp_v2_solver_single_order_solver{result="success",solver_type="ParaSwap"} 4

[nlordell]

Not a fan of passing metrics with the Solver::solve method, I would instead recommend passing the metrics in when constructing the solvers.

[nlordell]

I could do that if it seems appropriate.

Please do. You can run the solver and connect to http://localhost:9586 to get the metrics.

[nlordell]

I believe this PR closes #1015

[codecov-commenter]

Codecov Report

Merging #1248 (ef319bf) into main (e021831) will decrease coverage by 0.01%.
The diff coverage is 42.10%.

@@            Coverage Diff             @@
##             main    #1248      +/-   ##
==========================================
- Coverage   67.43%   67.42%   -0.02%     
==========================================
  Files         135      135              
  Lines       28344    28372      +28     
==========================================
+ Hits        19113    19129      +16     
- Misses       9231     9243      +12     

[nlordell]

Looks good to me! Thanks for fixing this 😄.

As a follow up task, could you add panels in our Grafana dashboard for this as well?

[bh2smith]

As a follow up task, could you add panels in our Grafana dashboard

Yes absolutely, although I am still trying to figure out how.