# Upgrade of MySQL version fails sometimes **URL:** \ **Category:** Percona Operator for MySQL\ **Created:** [June 10, 2025, 6:33pm UTC](https://forums.percona.com/t/upgrade-of-mysql-version-fails-sometimes/38271 "2025-06-10T18:33:20Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![AlexKuleshov](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/alexkuleshov/32/21220_2.png) [@AlexKuleshov](https://forums.percona.com/u/AlexKuleshov)\ **Post date:** [June 10, 2025, 6:33pm UTC](https://forums.percona.com/t/upgrade-of-mysql-version-fails-sometimes/38271/1 "2025-06-10T18:33:20Z")
## Description: Hello, I am using Percona MySQL Operator 0.9.0 with 2 MySQL instances with async replication. I noted that version upgrade is failing sometimes. I am testing upgrade from 8.0.37-29 to 8.0.39-30. Sometimes it works as expected, but sometimes orchestrator (correct me if it is not it responsible for it) failing to promote replica to new primary as as a result I have 2 read-only instances. In the orchestrator UI I see them as two Co-master with constantly growing replication lag: ![Orchestrator-mysql-cluster-ps-db-testing](https://us1.discourse-cdn.com/flex019/uploads/percona1/original/3X/7/2/726ab69dd9849c0d4b270ae78d49fe75fbd7f4f3.png) The reason seems replication lag that occurs during upgrade procedure (was 0 right before upgrade). But the successful recovery shows even bigger promoted replica lag seconds and still - promoted replica sql thread up-to-date. ## Logs: Here is the logs of operator and logs of recovery steps for successful upgrade and one that failed. Versions of upgrade are always the same. [operator.txt](https://forums.percona.com/uploads/short-url/3KVZSo8NIFWqysXhNrs25MRKkXn.txt) (6.2 KB) [failed-recovery.txt](https://forums.percona.com/uploads/short-url/3ph7s4zd3EgjhdRq5R70uajvCtE.txt) (1.9 KB) [successful-recovery.txt](https://forums.percona.com/uploads/short-url/p2mLm0hKwN5evc335FF0liLpfH.txt) (4.7 KB)