guicedee/guicedee-metrics

GuicedEE Metrics

Production-ready application metrics using Vert.x 5 Dropwizard Metrics and the MicroProfile Metrics 5.1 API.

Core Concept

Annotate your methods with standard @Counted, @Timed, and custom @MetricMethod — interceptors are bound through Guice AOP, metrics are collected into a shared MetricRegistry, and a Prometheus-compatible scrape endpoint is exposed on the Vert.x Web Router automatically.

Required Flow

1. Add com.guicedee:metrics dependency.
2. Configure metrics with @MetricsOptions:

   @MetricsOptions(
       enabled = true,
       jmxEnabled = true,
       baseName = "my-app",
       prometheus = @PrometheusOptions(enabled = true, endpoint = "/metrics")
   )
   public class MyAppConfig {}
   

3. Annotate methods:

   @Counted(name = "orders-placed", tags = {"env=prod"})
   public void placeOrder(Order order) { ... }
   
   @Timed(name = "order-processing-time")
   public void processOrder(Order order) { ... }
   

4. Configure module-info.java:

   module my.app {
       requires com.guicedee.metrics;
       opens my.app.services to com.google.guice;
   }
   

5. Bootstrap GuicedEE — metrics start automatically:

   IGuiceContext.registerModuleForScanning.add("my.app");
   IGuiceContext.instance().inject();
   // GET /metrics returns Prometheus exposition format
   

Metric Annotations

@Counted

Increments a monotonic counter each invocation. Place on method or class (applies to all methods).

@Timed

Measures execution time with quantile snapshots (p50, p75, p95, p98, p99, p999).

@MetricMethod

Custom GuicedEE annotation. Increments a named counter. If the method returns a numeric type, the counter value is returned instead.

Configuration

@MetricsOptions annotation

| Attribute | Purpose | |---|---| | enabled | Enable/disable metrics | | registryName | Dropwizard registry name | | jmxEnabled | Expose as JMX MBeans | | baseName | Metric name prefix | | monitoredHttpServerUris | URI patterns to monitor | | monitoredEventBusHandlers | EventBus handler patterns | | graphite | @GraphiteOptions for Graphite reporting | | prometheus | @PrometheusOptions for Prometheus endpoint |

Environment variable overrides

Every @MetricsOptions attribute can be overridden via system properties or environment variables.

Startup Flow

IGuiceContext.instance().inject()
 └─ MetricsPreStartup (scans for @MetricsOptions)
 └─ MetricsVertxConfigurator (configures DropwizardMetricsOptions on VertxBuilder)
 └─ MetricsModule (binds MetricRegistry, interceptors, reporters)
 └─ PrometheusMetricsConfigurator (registers GET /metrics handler)

Non-Negotiable Constraints

• Module must requires com.guicedee.metrics;.
• Intercepted classes must be in packages opened to com.google.guice.
• The metrics module is registered automatically — no provides needed.
• Guice AOP requires non-final, non-private methods for interception.