New counter for method errors

2 files changed, 52 insertions, 35 deletions

diff --git a/internal/middleware/cache/cache.go b/internal/middleware/cache/cache.go
index e39806c7d..6fcd48b81 100644
--- a/internal/middleware/cache/cache.go
+++ b/internal/middleware/cache/cache.go
@@ -6,7 +6,6 @@ import (
 	"sync"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/sirupsen/logrus"
 	diskcache "gitlab.com/gitlab-org/gitaly/internal/cache"
 	"gitlab.com/gitlab-org/gitaly/internal/praefect/protoregistry"
@@ -14,40 +13,6 @@ import (
 	"google.golang.org/grpc"
 )
 
-var (
-	rpcTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "gitaly_cacheinvalidator_rpc_total",
-			Help: "Total number of RPCs encountered by cache invalidator",
-		},
-	)
-	rpcOpTypes = prometheus.NewCounterVec(
-		prometheus.CounterOpts{
-			Name: "gitaly_cacheinvalidator_optype_total",
-			Help: "Total number of operation types encountered by cache invalidator",
-		},
-		[]string{"type"},
-	)
-)
-
-func init() {
-	prometheus.MustRegister(rpcTotal)
-	prometheus.MustRegister(rpcOpTypes)
-}
-
-func countRPCType(mInfo protoregistry.MethodInfo) {
-	rpcTotal.Inc()
-
-	switch mInfo.Operation {
-	case protoregistry.OpAccessor:
-		rpcOpTypes.WithLabelValues("accessor").Inc()
-	case protoregistry.OpMutator:
-		rpcOpTypes.WithLabelValues("mutator").Inc()
-	default:
-		rpcOpTypes.WithLabelValues("unknown").Inc()
-	}
-}
-
 // Invalidator is able to invalidate parts of the cache pertinent to a
 // specific repository. Before a repo mutating operation, StartLease should
 // be called. Once the operation is complete, the returned LeaseEnder should
diff --git a/internal/middleware/cache/prometheus.go b/internal/middleware/cache/prometheus.go
new file mode 100644
index 000000000..3cabfe9b5
--- /dev/null
+++ b/internal/middleware/cache/prometheus.go
@@ -0,0 +1,52 @@
+package cache
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"gitlab.com/gitlab-org/gitaly/internal/praefect/protoregistry"
+)
+
+var (
+	rpcTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "gitaly_cacheinvalidator_rpc_total",
+			Help: "Total number of RPCs encountered by cache invalidator",
+		},
+	)
+	rpcOpTypes = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "gitaly_cacheinvalidator_optype_total",
+			Help: "Total number of operation types encountered by cache invalidator",
+		},
+		[]string{"type"},
+	)
+	methodErrTotals = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "gitaly_cache_invalidator_error_total",
+			Help: "Total number of cache invalidation errors by method",
+		},
+		[]string{"method"},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(rpcTotal)
+	prometheus.MustRegister(rpcOpTypes)
+	prometheus.MustRegister(methodErrTotals)
+}
+
+// countMethodErr is a package var to allow for overriding in tests
+var (
+	countMethodErr = func(method string) { methodErrTotals.WithLabelValues(method).Add(1) }
+	countRPCType   = func(mInfo protoregistry.MethodInfo) {
+		rpcTotal.Inc()
+
+		switch mInfo.Operation {
+		case protoregistry.OpAccessor:
+			rpcOpTypes.WithLabelValues("accessor").Inc()
+		case protoregistry.OpMutator:
+			rpcOpTypes.WithLabelValues("mutator").Inc()
+		default:
+			rpcOpTypes.WithLabelValues("unknown").Inc()
+		}
+	}
+)