fix(metrics): gemini_cql_requests were not registered before metrics server is running

Signed-off-by: Dusan Malusev <dusan.malusev@scylladb.com>

Author: CodeLieutenant

pkg/metrics/metrics.go

@@ -0,0 +1,12 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var CQLRequests = promauto.NewCounterVec(prometheus.CounterOpts{
+	Name: "gemini_cql_requests",
+	Help: "How many CQL requests processed, partitioned by system and CQL query type aka 'method' (batch, delete, insert, update).",
+}, []string{"system", "method"},
+)

pkg/store/cqlstore.go

@@ -21,18 +21,17 @@ import (
 
 	"github.com/gocql/gocql"
 	"github.com/pkg/errors"
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/scylladb/gocqlx/v2/qb"
 	"go.uber.org/zap"
 
+	"github.com/scylladb/gemini/pkg/metrics"
 	"github.com/scylladb/gemini/pkg/stmtlogger"
 	"github.com/scylladb/gemini/pkg/typedef"
 )
 
 type cqlStore struct { //nolint:govet
 	session                 *gocql.Session
 	schema                  *typedef.Schema
-	ops                     *prometheus.CounterVec
 	logger                  *zap.Logger
 	system                  string
 	maxRetriesMutate        int
@@ -48,7 +47,7 @@ func (cs *cqlStore) name() string {
 func (cs *cqlStore) mutate(ctx context.Context, stmt *typedef.Stmt) error {
 	for range cs.maxRetriesMutate {
 		if err := cs.doMutate(ctx, stmt); err == nil {
-			cs.ops.WithLabelValues(cs.system, opType(stmt)).Inc()
+			metrics.CQLRequests.WithLabelValues(cs.system, opType(stmt)).Inc()
 			return nil
 		}
 
@@ -92,7 +91,7 @@ func (cs *cqlStore) load(ctx context.Context, stmt *typedef.Stmt) ([]map[string]
 	defer query.Release()
 
 	iter := query.Iter()
-	cs.ops.WithLabelValues(cs.system, opType(stmt)).Inc()
+	metrics.CQLRequests.WithLabelValues(cs.system, opType(stmt)).Inc()
 
 	result := loadSet(iter)
 

pkg/store/store.go

@@ -30,8 +30,6 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/pkg/errors"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 	"go.uber.org/multierr"
 	"gopkg.in/inf.v0"
 
@@ -72,21 +70,15 @@ type Config struct {
 }
 
 func New(schema *typedef.Schema, testCluster, oracleCluster *gocql.ClusterConfig, cfg Config, traceOut io.Writer, logger *zap.Logger) (Store, error) {
-	ops := promauto.NewCounterVec(prometheus.CounterOpts{
-		Name: "gemini_cql_requests",
-		Help: "How many CQL requests processed, partitioned by system and CQL query type aka 'method' (batch, delete, insert, update).",
-	}, []string{"system", "method"},
-	)
-
-	oracleStore, err := getStore("oracle", schema, oracleCluster, cfg, cfg.OracleLogStatementsFile, traceOut, logger, ops)
+	oracleStore, err := getStore("oracle", schema, oracleCluster, cfg, cfg.OracleLogStatementsFile, traceOut, logger)
 	if err != nil {
 		return nil, err
 	}
 
 	if testCluster == nil {
 		return nil, errors.New("test cluster is empty")
 	}
-	testStore, err := getStore("test", schema, testCluster, cfg, cfg.TestLogStatementsFile, traceOut, logger, ops)
+	testStore, err := getStore("test", schema, testCluster, cfg, cfg.TestLogStatementsFile, traceOut, logger)
 	if err != nil {
 		return nil, err
 	}
@@ -265,7 +257,6 @@ func getStore(
 	stmtLogFile string,
 	traceOut io.Writer,
 	logger *zap.Logger,
-	ops *prometheus.CounterVec,
 ) (out storeLoader, err error) {
 	if clusterConfig == nil {
 		return &noOpStore{
@@ -285,7 +276,6 @@ func getStore(
 		session:                 oracleSession,
 		schema:                  schema,
 		system:                  name,
-		ops:                     ops,
 		maxRetriesMutate:        cfg.MaxRetriesMutate + 10,
 		maxRetriesMutateSleep:   cfg.MaxRetriesMutateSleep,
 		useServerSideTimestamps: cfg.UseServerSideTimestamps,