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Problem-Pattern 'exceeded-quota'

ChartVersion

Overview

This chart will impose a ResourceQuota in the defined Namespace. The deployment will be scaled up using a CronJob to exceed the given quota.
By default the first scale up (2->3) will happen at 02:00 UTC, the second (3->4 replicas) at 02:20 UTC - this will exceed the ResourceQuota. At 02:30 UTC the Deployment will be scaled back to 2 replicas.
These schedules can be adjusted in cronjobs.yaml.

The CronJob and its required ServiceAccount will be deployed in the default "problem-patterns" Namespace (unless updated in the values.yaml).
All other components will adhere to the specified --namespace in the helm upgrade --install command.

Use-Case

In this demo we attempt to scale a deployment up in two steps. Initially we are scaling up by 1 replica which is within the quota's restrictions.
A few hours after that we try to scale up by 1 again which is beyond the restrictions imposed by the quota. The deployment cannot be scaled up any further and we end up with a kubernetes event that can potentially raise an alert if the workload is monitored.
To fully utilize this demo you might want to adjust the schedule according to your needs.

$ kubectl get events -n exceeded-quota
LAST SEEN   TYPE      REASON              OBJECT                                 MESSAGE
5m44s       Normal    ScalingReplicaSet   deployment/exceeded-quota              Scaled up replica set exceeded-quota-6f54cdfd7b to 2
4m38s       Normal    ScalingReplicaSet   deployment/exceeded-quota              Scaled up replica set exceeded-quota-6f54cdfd7b to 3 from 2
4m20s       Normal    ScalingReplicaSet   deployment/exceeded-quota              Scaled up replica set exceeded-quota-6f54cdfd7b to 4 from 3
4m04s       Warning   FailedCreate        replicaset/exceeded-quota-6f54cdfd7b   Error creating: pods "exceeded-quota-6f54cdfd7b-tchhp" is forbidden: exceeded quota: exceeded-quota, requested: requests.memory=100Mi, used: requests.memory=300Mi, limited: requests.memory=310Mi

Installation

Simply run a helm install command from the root of this repository:

helm upgrade --install exceeded-quota ./exceeded-quota --namespace exceeded-quota --create-namespace

Removal

Helm uninstall will get rid of everything but the namespaces. Thus we need to issue a kubectl delete manually to finish the cleanup.\

Note

The faultInjection.namespace will be left regardless. It is used by many of our charts, so we will not delete it.
Please remove it manually when you are sure it's not needed anymore.

helm uninstall exceeded-quota --namespace exceeded-quota
kubectl delete namespace exceeded-quota