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metrics.rs (3353B)

      1 use std::sync::OnceLock;
      2 
      3 use opentelemetry::{
      4     global,
      5     metrics::{Counter, Histogram},
      6 };
      7 
      8 /// Collection of order-related metric instruments.
      9 pub struct OrdersMetrics {
     10     /// Total number of checkout attempts (success + failure)
     11     pub checkout_attempts: Counter<u64>,
     12     /// Total number of failed checkouts, broken down by failure.reason
     13     pub checkout_failures: Counter<u64>,
     14     /// Wall-clock time to complete a checkout (seconds)
     15     pub checkout_duration: Histogram<f64>,
     16     /// Dollar amount of each completed order
     17     pub order_total_amount: Histogram<f64>,
     18     /// Number of line items per order
     19     pub order_items_count: Histogram<u64>,
     20 
     21     // Business KPI metrics: Conversion funnel
     22     /// Checkout funnel started (order creation initiated)
     23     pub funnel_started: Counter<u64>,
     24     /// Checkout funnel reached payment validation
     25     pub funnel_payment_info: Counter<u64>,
     26     /// Checkout funnel completed successfully
     27     pub funnel_completed: Counter<u64>,
     28 
     29     // Business KPI metrics: Time tracking
     30     /// Time from checkout start to completion
     31     pub time_to_checkout: Histogram<f64>,
     32 }
     33 
     34 /// Singleton storage for the metrics instruments.
     35 static METRICS: OnceLock<OrdersMetrics> = OnceLock::new();
     36 
     37 /// Returns a reference to the lazily-initialized orders metrics.
     38 pub fn metrics() -> &'static OrdersMetrics {
     39     METRICS.get_or_init(|| {
     40         let meter = global::meter("orders-service");
     41 
     42         OrdersMetrics {
     43             checkout_attempts: meter
     44                 .u64_counter("orders.checkout.attempts")
     45                 .with_description("Total checkout attempts")
     46                 .build(),
     47             checkout_failures: meter
     48                 .u64_counter("orders.checkout.failures")
     49                 .with_description("Total failed checkouts")
     50                 .build(),
     51             checkout_duration: meter
     52                 .f64_histogram("orders.checkout.duration")
     53                 .with_description("Time to complete checkout")
     54                 .with_unit("s")
     55                 .build(),
     56             order_total_amount: meter
     57                 .f64_histogram("orders.total.amount")
     58                 .with_description("Order total in dollars")
     59                 .with_unit("USD")
     60                 .build(),
     61             order_items_count: meter
     62                 .u64_histogram("orders.items.count")
     63                 .with_description("Number of items per order")
     64                 .build(),
     65 
     66             // Business KPI metrics: Conversion funnel
     67             funnel_started: meter
     68                 .u64_counter("checkout.funnel.started")
     69                 .with_description("Checkout attempts initiated")
     70                 .build(),
     71             funnel_payment_info: meter
     72                 .u64_counter("checkout.funnel.payment_info")
     73                 .with_description("Checkout reached payment validation")
     74                 .build(),
     75             funnel_completed: meter
     76                 .u64_counter("checkout.funnel.completed")
     77                 .with_description("Checkout successfully completed")
     78                 .build(),
     79 
     80             // Business KPI metrics: Time tracking
     81             time_to_checkout: meter
     82                 .f64_histogram("checkout.time_to_completion")
     83                 .with_description("Time from checkout start to completion")
     84                 .with_unit("s")
     85                 .build(),
     86         }
     87     })
     88 }