Update notes

Although MOSK 24.3.1 is classified as a patch release, as a cloud operator, you will be performing a major update regardless of the upgrade path: whether you are upgrading from patch 24.2.5 or major version 24.3. This is because of the Mirantis Container Runtime update to 23.0.15.

This section describes the specific actions you need to complete to accurately plan and successfully perform the update. Consider this information as a supplement to the generic update procedure published in Operations Guide: Update a MOSK cluster.

Cluster update schema

You can update to the 24.3.1 version from the following cluster versions:

  • 24.3 (released on October 16, 2024)

  • 24.2.5 (released on December 09, 2024)

For the detailed cluster update schema, refer to Managed cluster update schema.

Optional migration of container runtime from Docker to containerd

MOSK 24.3.1 enables optional migration of container runtime from Docker to containerd. Usage of containerd introduces a major enhancement for cloud workloads running on top of MOSK, as it helps minimize the network connectivity downtime caused by underlying infrastructure updates.

To minimize the number of required maintenance windows, Mirantis recommends that cloud operators switch to the containerd runtime on the nodes simultaneously with their upgrade to Ubuntu 22.04 if the Ubuntu upgrade has not been completed before.

Note

Migration from Docker to containerd will become mandatory in MOSK 25.1.

Required action

Upgrade Ubuntu to 22.04

Update impact and maintenance windows planning

The following table provides details on the update impact on a MOSK cluster.

Impact during update to MOSK 24.3.1

Updated component

Impact on cloud users

Impact on cloud workloads

OpenStack and Tungsten Fabric

  • ~1% of read operations on cloud API resources may fail

  • ~8% of create and update operations on cloud API resources may fail

Open vSwitch networking - interruption of the North-South connectivity, depending on the type of virtual routers used by a workload:

  • Distributed (DVR) routers - no interruption

  • Non-distributed routers, High Availability (HA) mode - interruption up to 1 minute, usually less than 5 seconds

  • Non-distributed routers, non-HA mode - interruption up to 10 minutes

Tungsten Fabric networking - no impact

Ceph

~1% of read operations on object storage API may fail

IO performance degradation for Ceph-backed virtual storage devices. Pay special attention to the known issue 50566 that may affect the maintenance window.

Host OS components

No impact

Instance network connectivity interruption up to 5 minutes

Host OS kernel

No impact

Restart of instances due to the hypervisor reboot 0
0

Host operating system needs to be rebooted for the kernel update to be applied. Configure live-migration of workloads to avoid the impact on the instances running on a host.

To properly plan the update maintenance window, use the following documentation:

Known issues during the update

Before updating the cluster, be sure to review the potential issues that may arise during the process and the recommended solutions to address them, as outlined in Update known issues.

Post-update actions

Upgrade Ubuntu to 22.04 and migrate to containerd runtime

MOSK 24.3 release series is the last release series to support Ubuntu 20.04 as the host operating system. Ubuntu 20.04 reaches end-of-life in April 2025. Therefore, Mirantis encourages all MOSK users to upgrade their clusters to Ubuntu 22.04 as soon as possible after getting to the 24.3 series. A host operating system upgrade requires reboot of the nodes and can be performed in small batches.

Also, MOSK 24.3.1 introduces the new container runtime for the underlying Kubernetes cluster - containerd. The migration from Docker to containerd in 24.3.1 is optional and requires node cordoning and draining. Therefore, if you decide to start using containerd and have not yet upgraded to Ubuntu 22.04, Mirantis highly recommends that these two changes be applied simultaneously to every node to minimize downtime for cloud workloads and users:

Note

In MOSK 24.3.x, the default container runtime remains Docker for greenfield deployments. Support for greenfield deployments based on containerd will be announced in one of the following releases.

Warning

Update of management or MOSK clusters running Ubuntu 20.04 or Docker runtime will not be possible in the following product series.

Caution

Usage of third-party software, which is not part of Mirantis-supported configurations, for example, the use of custom DPDK modules, may block upgrade of an operating system distribution. Users are fully responsible for ensuring the compatibility of such custom components with the latest supported Ubuntu version.

Back up custom Grafana dashboards

In MOSK 25.1 and Container Cloud 2.29.0, Grafana will be updated to version 11 where the following deprecated Angular-based plugins will be automatically migrated to the React-based ones:

  • Graph (old) -> Time Series

  • Singlestat -> Stat

  • Stat (old) -> Stat

  • Table (old) -> Table

  • Worldmap -> Geomap

This migration may corrupt custom Grafana dashboards that have Angular-based panels. Therefore, if you have such dashboards, back them up and manually upgrade Angular-based panels during the course of MOSK 24.3 and Container Cloud 2.28.x (Cluster releases 17.3.x and 16.3.x) to prevent custom appearance issues after plugin migration in Container Cloud 2.29.0 and MOSK 25.1.

Note

All Grafana dashboards provided by StackLight are also migrated to React automatically. For the list of default dashboards, see View Grafana dashboards.

Warning

For management clusters that are updated automatically, it is important to prepare the backup before Container Cloud 2.29.0 is released. Otherwise, custom dashboards using Angular-based plugins may be corrupted.

For managed clusters, you can perform the backup after the Container Cloud 2.29.0 release date but before updating them to MOSK 25.1.

See also