add subset algorithm

rpcx/internal/codes/accept.go

@@ -0,0 +1,15 @@
+package codes
+
+import (
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func Acceptable(err error) bool {
+	switch status.Code(err) {
+	case codes.DeadlineExceeded, codes.Internal, codes.Unavailable, codes.DataLoss:
+		return false
+	default:
+		return true
+	}
+}