# HA monitoring setup in Kubernetes via VictoriaMetrics Cluster
**The guide covers:**
* High availability monitoring via [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) in [Kubernetes](https://kubernetes.io/) with Helm charts
* How to store metrics
* How to scrape metrics from k8s components using a service discovery
* How to visualize stored data
* How to store metrics in [VictoriaMetrics](https://victoriametrics.com)
**Preconditions**
* [Kubernetes cluster 1.19.12-gke.2100](https://cloud.google.com/kubernetes-engine). We use GKE cluster from [GCP](https://cloud.google.com/) but this guide also applies to any Kubernetes cluster. For example, [Amazon EKS](https://aws.amazon.com/ru/eks/).
Please see the relevant [VictoriaMetrics Helm repository](https://docs.victoriametrics.com/guides/k8s-monitoring-via-vm-cluster.html#1-victoriametrics-helm-repository) section in previous guides.
## 2. Install VictoriaMetrics Cluster from the Helm chart
* The `Helm install vmcluster vm/victoria-metrics-cluster` command installs [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) to the default [namespace](https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/).
*`dedup.minScrapeInterval: 1ms` configures [de-duplication](https://docs.victoriametrics.com/#deduplication) for the cluster that de-duplicates data points in the same time series if they fall within the same discrete 1s bucket. The earliest data point will be kept. In the case of equal timestamps, an arbitrary data point will be kept.
*`replicationFactor: 2` Replication factor for the ingested data, i.e. how many copies should be made among distinct `-storageNode` instances. If the replication factor is greater than one, the deduplication must be enabled on the remote storage side.
*`podAnnotations: prometheus.io/scrape: "true"` enables the scraping of metrics from the vmselect, vminsert and vmstorage pods.
*`podAnnotations:prometheus.io/port: "some_port" ` enables the scraping of metrics from the vmselect, vminsert and vmstorage pods from corresponding ports.
*`replicaCount: 3` creates three replicas of vmselect, vminsert and vmstorage.
The expected result of the command execution is the following:
To scrape metrics from Kubernetes with a VictoriaMetrics Cluster we will need to install [vmagent](https://docs.victoriametrics.com/vmagent.html) with some additional configurations. To do so, please run the following command:
*`remoteWriteUrls: - http://vmcluster-victoria-metrics-cluster-vminsert.default.svc.cluster.local:8480/insert/0/prometheus/` configures `vmagent` to write scraped metrics to the `vmselect service`.
To verify that metrics are present in the VictoriaMetrics send a curl request to the `vmselect` service from kubernetes or setup Grafana and check it via the web interface.
Run the following command to see the list of services:
* Query `http://127.0.0.1:8481/select/0/prometheus/api/v1/query_range` uses [VictoriaMetrics querying API](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format) to fetch previously stored data points;
* Argument `query=count(up{kubernetes_pod_name=~".*vmselect.*"})` specifies the query we want to execute. Specifically, we calculate the number of `vmselect` pods.
* Additional arguments `start=-10m&step=1m'` set requested time range from -10 minutes (10 minutes ago) to now (default value if `end` argument is omitted) and step (the distance between returned data points) of 1 minute;
* By adding `| jq` we pass the output to the jq utility which outputs information in json format
The expected result of the query `count(up{kubernetes_pod_name=~".*vmselect.*"})` should be equal to `3` - the number of replicas we set via `replicaCount` parameter.
To test via Grafana, we need to install it first. [Install and connect Grafana to VictoriaMetrics](https://docs.victoriametrics.com/guides/k8s-monitoring-via-vm-cluster.html#4-install-and-connect-grafana-to-victoriametrics-with-helm), login into Grafana and open the metrics [Explore](http://127.0.0.1:3000/explore) page.
Choose `victoriametrics` from the list of datasources and enter `count(up{kubernetes_pod_name=~".*vmselect.*"})` to the **Metric browser** field as shown on the screenshot, then press **Run query** button:
As you can see, after we scaled down the `vmstorage` replicas number from three to two pods, metrics are still available and correct. The response is not partial as it was before scaling. Also we see that query `count(up{kubernetes_pod_name=~".*vmselect.*"})` returns the same value as before.
To confirm that the number of `vmstorage` pods is equivalent to two, execute the following request in Grafana Explore: