Tungsten Fabric known issues and limitations

This section lists the Tungsten Fabric known issues with workarounds for the Mirantis OpenStack for Kubernetes release 21.3.

Limitations

Tungsten Fabric does not provide the following functionality:

  • Automatic generation of network port records in DNSaaS (Designate) as Neutron with Tungsten Fabric as a backend is not integrated with DNSaaS. As a workaround, you can use the Tungsten Fabric built-in DNS service that enables virtual machines to resolve each other names.

  • Secret management (Barbican). You cannot use the certificates stored in Barbican to terminate HTTPs in a load balancer.

  • Role Based Access Control (RBAC) for Neutron objects.

  • Modification of custom vRouter DaemonSets based on the SR-IOV definition in the OsDpl CR.

Learn more

MOS Reference Architecture: Tungsten Fabric known limitations

[10096] tf-control does not refresh IP addresses of Cassandra pods

The tf-control service resolves the DNS names of Cassandra pods at startup and does not update them if Cassandra pods got new IP addresses, for example, in case of a restart. As a workaround, to refresh the IP addresses of Cassandra pods, restart the tf-control pods one by one:

Caution

Before restarting the tf-control pods:

  • Verify that the new pods are successfully spawned.

  • Verify that no vRouters are connected to only one tf-control pod that will be restarted.

kubectl -n tf delete pod tf-control-<hash>

[13755] TF pods switch to CrashLoopBackOff after a simultaneous reboot

Rebooting all Cassandra cluster TFConfig or TFAnalytics nodes, maintenance, or other circumstances that cause the Cassandra pods to start simultaneously may cause a broken Cassandra TFConfig and/or TFAnalytics cluster. In this case, Cassandra nodes do not join the ring and do not update the IPs of the neighbor nodes. As a result, the TF services cannot operate Cassandra cluster(s).

To verify that a Cassandra cluster is affected:

Run the nodetool status command specifying the config or analytics cluster and the replica number:

kubectl -n tf exec -it tf-cassandra-<config/analytics>-dc1-rack1-<replica number> -c cassandra -- nodetool status

Example of system response with outdated IP addresses:

Datacenter: DC1
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address         Load       Tokens       Owns (effective)  Host ID                               Rack
DN  <outdated ip>   ?          256          64.9%             a58343d0-1e3f-4d54-bcdf-9b9b949ca873  r1
DN  <outdated ip>   ?          256          69.8%             67f1d07c-8b13-4482-a2f1-77fa34e90d48  r1
Datacenter: dc1
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address          Load       Tokens       Owns (effective)  Host ID                               Rack
UN  <actual ip>      3.84 GiB   256          65.2%             7324ebc4-577a-425f-b3de-96faac95a331  rack1

Workaround:

Manually delete a Cassandra pod from the failed config or analytics cluster to re-initiate the bootstrap process for one of the Cassandra nodes:

kubectl -n tf delete pod tf-cassandra-<config/analytics>-dc1-rack1-<replica number>