feat: add metrics

[chronark]

Summary by CodeRabbit

• New Features

  • Introduced new telemetry metrics to track the number of batches processed per flush and the duration of each batch persistence operation.
  • Error logs for failed batch persistence now include the duration of the failed operation.

• Chores

  • Enhanced observability by adding detailed batch processing metrics for improved monitoring.

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Latest commit: 1e8fa3e

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Review failed

The pull request is closed.

📝 Walkthrough

Walkthrough

This change adds two new telemetry metrics to the batch processing logic in the buffer processor: one for the number of batches processed per flush and another for the duration of each batch persist operation. It also updates the telemetry setup to initialize and handle these new metrics.

Changes

File(s)	Change Summary
apps/chproxy/buffer.go	Instrumented batch processing with metrics for batch count per flush and per-batch persist time.
apps/chproxy/otel.go	Added and initialized two new metrics in telemetry: batch persist duration and flush batch count.

Sequence Diagram(s)

sequenceDiagram
    participant BufferProcessor
    participant Telemetry

    BufferProcessor->>Telemetry: Record FlushBatchCount (number of batches in flush)
    loop For each batch in flush
        BufferProcessor->>Telemetry: Start timer for BatchPersistDuration
        BufferProcessor->>BufferProcessor: Persist batch
        BufferProcessor->>Telemetry: Record BatchPersistDuration (per batch)
        alt Persist fails
            BufferProcessor->>BufferProcessor: Log error with duration attribute
        end
    end

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Estimated code review effort

2 (~15 minutes)

Possibly related PRs

• fix: protect against running out of memory #3644: Both PRs modify the startBufferProcessor function, with this PR focusing on metrics and fix: protect against running out of memory #3644 on batch size and flushing logic.
• feat(chproxy): Add OTEL instrumentation #2949: This PR extends OTEL telemetry setup, building on the metric definitions and initialization introduced in feat(chproxy): Add OTEL instrumentation #2949.

Suggested reviewers

• perkinsjr
• mcstepp
• MichaelUnkey
• ogzhanolguncu

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📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between f42e581 and 1e8fa3e.

📒 Files selected for processing (2)

• apps/chproxy/buffer.go (2 hunks)
• apps/chproxy/otel.go (3 hunks)

✨ Finishing Touches

• 📝 Generate Docstrings

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[github-actions]

Thank you for following the naming conventions for pull request titles! 🙏