feat: add metrics (#3624)

core/stores/redis/redisclustermanager.go

@@ -3,6 +3,7 @@ package redis
 import (
 	"crypto/tls"
 	"io"
+	"runtime"
 	"strings"
 
 	red "github.com/go-redis/redis/v8"
@@ -11,7 +12,11 @@ import (
 
 const addrSep = ","
 
-var clusterManager = syncx.NewResourceManager()
+var (
+	clusterManager = syncx.NewResourceManager()
+	// clusterPoolSize is default pool size for cluster type of redis.
+	clusterPoolSize = 5 * runtime.GOMAXPROCS(0)
+)
 
 func getCluster(r *Redis) (*red.ClusterClient, error) {
 	val, err := clusterManager.GetResource(r.Addr, func() (io.Closer, error) {
@@ -33,6 +38,15 @@ func getCluster(r *Redis) (*red.ClusterClient, error) {
 			store.AddHook(hook)
 		}
 
+		connCollector.registerClient(&statGetter{
+			clientType: ClusterType,
+			key:        r.Addr,
+			poolSize:   clusterPoolSize,
+			poolStats: func() *red.PoolStats {
+				return store.PoolStats()
+			},
+		})
+
 		return store, nil
 	})
 	if err != nil {