This section describes the specific actions you as a Cloud Operator need to complete to accurately plan and successfully perform your Mirantis OpenStack for Kubernetes (MOSK) cluster to the version 22.2. Consider this information as a supplement to the generic update procedure published in Operations Guide: Update a MOSK cluster.
Additionally, read through the Cluster update known issues for the problems that are known to occur during update with recommended workarounds.
Your MOSK cluster will obtain the newly implemented capabilities automatically with no significant impact on the update procedure.
Update impact and maintenance windows planning¶
Up to 1 minute of downtime for TF data plane¶
During the Kubernetes master nodes update, there is a downtime on Kubernetes cluster’s internal DNS service. Thus, Tungsten Fabric vRouter pods lose connection with the control plane resulting in up to 1 minute of downtime for the Tungsten Fabric data plane nodes and impact on the tenant networking.
Manual restart of TF vRouter agent pods¶
To complete the update of the cluster with Tungsten Fabric, manually restart Tungsten Fabric vRouter agent pods on all compute nodes. The restart of a vRouter agent on a compute node will cause up to 30-60 seconds of networking downtime per instance hosted there. If downtime is unacceptable for some workloads, we recommend that you migrate them before restarting the vRouter pods.
Under certain rare circumstances, the reload of the vRouter kernel
module triggered by the restart of a vRouter agent can hang due to
the inability to complete the
drop_caches operation. Watch the status
and logs of the vRouter agent being restarted and trigger the reboot of
the node, if necessary.