add retry for schema update (#5924)

Signed-off-by: Tiger <[email protected]>

query/common_test.go

@@ -29,11 +29,17 @@ import (
 )
 
 func setSchema(schema string) {
-	err := client.Alter(context.Background(), &api.Operation{
-		Schema: schema,
-	})
-	if err != nil {
-		panic(fmt.Sprintf("Could not alter schema. Got error %v", err.Error()))
+	for retry := 0; retry < 3; retry++ {
+		err := client.Alter(context.Background(), &api.Operation{
+			Schema: schema,
+		})
+		if err == nil {
+			return
+		}
+		// We'll panic if we are in last iteration.
+		if retry == 2 {
+			panic(fmt.Sprintf("Could not alter schema. Got error %v", err.Error()))
+		}
 	}
 }