chore: disable internal retries when using runner

retry.go

@@ -22,6 +22,7 @@ import (
 
 	"cloud.google.com/go/spanner"
 	"github.com/googleapis/gax-go/v2"
+	spannerdriver "github.com/googleapis/go-sql-spanner"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"gorm.io/gorm"
@@ -30,8 +31,15 @@ import (
 // RunTransaction executes a transaction on Spanner using the given
 // gorm database, and retries the transaction if it is aborted by Spanner.
 func RunTransaction(ctx context.Context, db *gorm.DB, fc func(tx *gorm.DB) error, opts ...*sql.TxOptions) error {
+	// Disable internal (checksum-based) retries on the Spanner database/SQL connection.
+	var opt *sql.TxOptions
+	// Note: gorm also only uses the first option, so it is safe to pick just the first element in the slice.
+	if len(opts) > 0 {
+		opt = opts[0]
+	}
+	opt.Isolation = spannerdriver.WithDisableRetryAborts(opt.Isolation)
 	for {
-		err := db.Transaction(fc, opts...)
+		err := db.Transaction(fc, opt)
 		if err == nil {
 			return nil
 		}

spanner_test.go

@@ -260,15 +260,20 @@ func TestRunTransaction(t *testing.T) {
 	server.TestSpanner.PutExecutionTime(testutil.MethodCommitTransaction, testutil.SimulatedExecutionTime{
 		Errors: []error{status.Error(codes.Aborted, "Aborted")},
 	})
+	attempts := 0
 	if err := RunTransaction(ctx, db, func(tx *gorm.DB) error {
+		attempts++
 		if err := tx.Create(&s).Error; err != nil {
 			return err
 		}
 		return nil
 	}, &sql.TxOptions{}); err != nil {
 		t.Fatal(err)
 	}
-	// Now verify that the insert was executed twice.
+	// Now verify that the insert was executed twice and that the function was called twice.
+	if g, w := attempts, 2; g != w {
+		t.Fatalf("attempts mismatch\n Got: %v\nWant: %v", g, w)
+	}
 	reqs = drainRequestsFromServer(server.TestSpanner)
 	execReqs = requestsOfType(reqs, reflect.TypeOf(&spannerpb.ExecuteSqlRequest{}))
 	insertReqs = filter(execReqs, insertSql)