Monitoring the application health
Kubernetes Liveness and Readiness probes are used to monitor and control the health of the NetBackup primary server and media server pods. The probes collectively also called as health probes, keep checking the availability and readiness of the pods, and take designated actions in case of any issues. The kubelet uses liveness probes to know when to restart a container, and readiness probes to know when a container is ready. For more information, refer to the Kubernetes documentation.
Configure Liveness, Readiness and Startup Probes | Kubernetes
The health probes monitor the following for the NetBackup deployment:
Mount directories are present for the data/catalog at
/mnt/nbdataand the log volume at/mnt/nblogs.bp.confis present at/usr/openv/netbackupNetBackup services are running as expected.
Following table describes the actions and time intervals configured for the probes:
Table:
Action | Description | Probe name | Primary server (seconds) | Media server (seconds) | Request router (seconds) |
|---|---|---|---|---|---|
Initial delay | This is the delay that tells kubelet to wait for a given number of seconds before performing the first probe. | Readiness Probe | 120 | 0 | 60 |
Liveness Probe | 300 | 90 | 120 | ||
Periodic execution time | This action specifies that kubelet should perform a probe every given number of seconds. | Readiness Probe | 30 | 30 | 60 |
Liveness Probe | 90 | 90 | 60 | ||
Threshold for failure retries | This action specifies that kubelet should retry the probe for given number of times in case a probe fails, and then restart a container. | Readiness Probe | 1 | 1 | 1 |
Liveness Probe | 5 | 5 | 5 |
Heath probes are run using the nb-health command. If you want to manually run the nb-health command, the following options are available:
This option disables the health check that will mark pod as not ready (0/1).
This option enables the already disabled health check in the pod. This marks the pod in ready state(1/1) again if all the NetBackup health checks are passed.
This option deactivates the health probe functionality in pod. Pod remains in ready state(1/1). This will avoid pod restarts due to health probes like liveness, readiness probe failure. This is the temporary step and not recommended to use in usual case.
This option activates the health probe functionality that has been deactivated earlier using the option.
You can manually disable or enable the probes if required. For example, if for any reason you need to exec into the pod and restart the NetBackup services, the health probes should be disabled before restarting the services, and then they should be enabled again after successfully restarting the NetBackup services. If you do not disable the health probes during this process, the pod may restart due to the failed health probes.
Note:
It is recommended to disable the health probes only temporarily for troubleshooting purposes. When the probes are disabled, the web UI is not accessible in case of the primary server pod, and the media server pods cannot be scaled up. Then the health probes must be enabled again to successfully run NetBackup.
To disable or enable the health probes
- Execute the following command in the Primary or media server pod as required:
kubectl exec -it -n <namespace> <primary/media-server-pod-name> -- /bin/bash
- To disable the probes, run the /opt/veritas/vxapp-manage/nb-health disable command. Then the pod goes into the not ready (0/1) state.
- To enable the probes, run the "/opt/veritas/vxapp-manage/nb-health enable" command. Then the pod will be back into the ready (1/1) state.
You can check pod events in case of probe failures. To get more details use the kubectl describe <primary/media-pod-name> -n <namesapce> command.
To disable or enable the request router health probes
- Execute the following command in the request router pod as required:
kubectl exec -it -n <namespace> <request-router-pod-name> -- /bin/bash
- To disable the probes, run the /opt/veritas/vxapp-manage/health.sh disable command. Then the pod goes into the not ready (0/1) state.
- To enable the probes, run the /opt/veritas/vxapp-manage/health.sh enable command. Then the pod will be back into the ready (1/1) state.
You can check pod events in case of probe failures. To get more details use the kubectl describe -n command.