metrics

cmd/cart/main.go

@@ -27,18 +27,17 @@ import (
 	"git.k6n.net/mats/platform/config"
 	"git.k6n.net/mats/platform/event"
 	"git.k6n.net/mats/platform/rabbit"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/redis/go-redis/v9"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 var (
-	grainSpawns = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "cart_grain_spawned_total",
-		Help: "The total number of spawned grains",
-	})
+	// cartMetrics is the shared prometheus instrumentation for the
+	// cart actor pool and event log. Built once at process start; nil
+	// is not expected in production but the actor package's
+	// touch sites are nil-safe so a test binary can pass nil.
+	cartMetrics = actor.NewMetrics("cart")
 )
 
 func init() {
@@ -258,13 +257,14 @@ func main() {
 	)
 
 	diskStorage := actor.NewDiskStorage[cart.CartGrain](config.EnvString("CART_DIR", "data"), reg)
+	diskStorage.SetMetrics(cartMetrics)
 	poolConfig := actor.GrainPoolConfig[cart.CartGrain]{
 		MutationRegistry: reg,
 		Storage:          diskStorage,
+		Metrics:          cartMetrics,
 		Spawn: func(ctx context.Context, id uint64) (actor.Grain[cart.CartGrain], error) {
 			_, span := tracer.Start(ctx, fmt.Sprintf("Spawn cart id %d", id))
 			defer span.End()
-			grainSpawns.Inc()
 			ret := cart.NewCartGrain(id, time.Now())
 			// Set baseline lastChange at spawn; replay may update it to last event timestamp.
 

cmd/cart/pool-server.go

@@ -16,8 +16,6 @@ import (
 	messages "git.k6n.net/mats/go-cart-actor/proto/cart"
 
 	"git.k6n.net/mats/go-cart-actor/pkg/voucher"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/anypb"
@@ -28,16 +26,13 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-var (
-	grainMutations = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "cart_grain_mutations_total",
-		Help: "The total number of mutations",
-	})
-	grainLookups = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "cart_grain_lookups_total",
-		Help: "The total number of lookups",
-	})
-)
+// Pool metrics (cart_grain_spawned_total, cart_grain_lookups_total,
+// cart_mutations_total, cart_remote_negotiation_total,
+// cart_connected_remotes, …) are bumped centrally by SimpleGrainPool
+// — see pkg/actor/simple_grain_pool.go. The cart Metrics is
+// registered once in cmd/cart/main.go and shared with DiskStorage
+// via SetMetrics, so the per-handler counters this file used to
+// maintain are no longer needed.
 
 type PoolServer struct {
 	actor.GrainPool[cart.CartGrain]
@@ -122,7 +117,6 @@ func (s *PoolServer) AddSkuToCartHandler(w http.ResponseWriter, r *http.Request,
 	if err != nil {
 		return err
 	}
-	grainMutations.Add(float64(len(data.Mutations)))
 	return s.WriteResult(w, data)
 }
 
@@ -496,9 +490,8 @@ func (s *PoolServer) ProxyHandler(fn func(w http.ResponseWriter, r *http.Request
 			hostAttr := attribute.String("other host", ownerHost.Name())
 			span.SetAttributes(hostAttr)
 			proxyCalls.Add(ctx, 1, metric.WithAttributes(hostAttr))
-			handled, err := ownerHost.Proxy(uint64(cartId), w, r, nil)
+				handled, err := ownerHost.Proxy(uint64(cartId), w, r, nil)
 
-			grainLookups.Inc()
 			if err == nil && handled {
 				return nil
 			}