[RFC] Remove/hook unused metrics #2901

[mdhaduk]

Opening this as a Draft PR

Changes

Removed unused metrics; used this script to generally identify which metrics might not be used, then manually removed them

To identify unused metrics, I used the following convention

For SharedIncMetric:

• Not incremented/added to
• Not stored
• Not fetched

For LatencyAggregateMetrics:

• Not calling record_latency_metrics

Metrics Removed:

• sync_response_fails
• sync_vmm_send_timeout_count
• deprecated_cmd_line_api_calls
• log_fails
• device_events
• rx_partial_writes
• tx_partial_reads

Reason

Resolving issue #2901 - Remove/hook unused metrics

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license. For more information on following Developer Certificate of Origin and signing off your commits, please check CONTRIBUTING.md.

PR Checklist

• [x] I have read and understand CONTRIBUTING.md.
• [x] I have run tools/devtool checkstyle to verify that the PR passes the automated style checks.
• [x] I have described what is done in these changes, why they are needed, and how they are solving the problem in a clear and encompassing way.
• [x] I have updated any relevant documentation (both in code and in the docs) in the PR.
• [x] I have mentioned all user-facing changes in CHANGELOG.md.
• [x] If a specific issue led to this PR, this PR closes the issue.
• [x] When making API changes, I have followed the Runbook for Firecracker API changes.
• [x] I have tested all new and changed functionalities in unit tests and/or integration tests.
• [x] I have linked an issue to every new TODO.

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• [ ] This functionality cannot be added in rust-vmm.