chore: relay_and_check_mempool metric

[carneiro-cw]

No description provided.

[github-actions]

PR Reviewer Guide 🔍

⏱️ Estimated effort to review [1-5]	2
🧪 Relevant tests	No
🔒 Security concerns	No
⚡ Key issues to review	Logging and Monitoring: The PR adds metric logging for the duration of the relay_and_check_mempool function. Ensure that these metrics are properly integrated and visualized in the monitoring tools.
	Async Task Handling: The PR does not introduce any blocking tasks within the tokio context, which aligns with the project guidelines.

[github-actions]

PR Code Suggestions ✨

Category	Suggestion	Score
Possible issue	Add error handling for time measurement to enhance robustness Consider handling potential errors or exceptions when calling start.elapsed() as this might fail or panic under certain conditions (e.g., system clock adjustments). Using a safe approach to handle such scenarios can improve the robustness of the code. src/eth/relayer/external.rs [273] -metrics::inc_relay_and_check_mempool(start.elapsed()); +if let Ok(elapsed) = start.elapsed() { + metrics::inc_relay_and_check_mempool(elapsed); +} else { + tracing::warn!("Failed to measure elapsed time for metrics."); +} Suggestion importance[1-10]: 10 Why: Adding error handling for the time measurement improves the robustness of the code by preventing potential panics or failures due to system clock adjustments. This is a critical improvement for reliability.	10
Maintainability	Conditionally execute metrics-related code based on the feature flag Ensure that the elapsed time measurement and the increment of the metric are wrapped in a conditional check for the feature flag to prevent execution when the feature is disabled. This ensures that the metrics-related code is only executed when the corresponding feature is enabled. src/eth/relayer/external.rs [273] +#[cfg(feature = "metrics")] metrics::inc_relay_and_check_mempool(start.elapsed()); Suggestion importance[1-10]: 9 Why: Wrapping the metrics-related code in a conditional check ensures that it only runs when the feature is enabled, which is crucial for maintaining the intended behavior of the code and avoiding unnecessary execution.	9
Enhancement	Refine the feature flag used for metrics to improve feature granularity Consider using a more specific feature flag for the metrics related to relay_and_check_mempool to avoid enabling them unintentionally with a broader metrics feature. This can help in controlling the granularity of metrics collection and improve the manageability of feature flags. src/eth/relayer/external.rs [235-236] -#[cfg(feature = "metrics")] +#[cfg(feature = "relay_and_check_mempool_metrics")] let start = metrics::now(); Suggestion importance[1-10]: 8 Why: This suggestion improves the granularity of feature flags, making the codebase more manageable and reducing the risk of unintentionally enabling metrics. It is a significant enhancement for maintainability.	8
	Improve the precision of time measurement for metrics To ensure that the metric increment reflects accurate timings, consider using a more precise time measurement method if available in the metrics module, or ensure that the current method provides the necessary precision. src/eth/relayer/external.rs [236] -let start = metrics::now(); +let start = metrics::precise_now(); # Assuming `precise_now` exists and offers higher precision Suggestion importance[1-10]: 7 Why: While improving the precision of time measurement can be beneficial, it is not clear if metrics::precise_now() exists. Assuming it does, this change would enhance the accuracy of the metrics, but the impact is less critical compared to other suggestions.	7