# 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/). * [Helm 3 ](https://helm.sh/docs/intro/install) * [kubectl 1.21](https://kubernetes.io/docs/tasks/tools/install-kubectl) * [jq](https://stedolan.github.io/jq/download/) tool ## 1. VictoriaMetrics Helm repository 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 Execute the following command in your terminal:
```yaml cat < * 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-deplication](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: ```console NAME: vmcluster LAST DEPLOYED: Thu Jul 29 13:33:51 2021 NAMESPACE: default STATUS: deployed REVISION: 1 TEST SUITE: None NOTES: Write API: The VictoriaMetrics write api can be accessed via port 8480 via the following DNS name from within your cluster: vmcluster-victoria-metrics-cluster-vminsert.default.svc.cluster.local Get the VictoriaMetrics insert service URL by running these commands in the same shell: export POD_NAME=$(kubectl get pods --namespace default -l "app=vminsert" -o jsonpath="{.items[0].metadata.name}") kubectl --namespace default port-forward $POD_NAME 8480 You need to update your Prometheus configuration file and add the following lines to it: prometheus.yml remote_write: - url: "http:///insert/0/prometheus/" for example - inside the Kubernetes cluster: remote_write: - url: "http://vmcluster-victoria-metrics-cluster-vminsert.default.svc.cluster.local:8480/insert/0/prometheus/" Read API: The VictoriaMetrics read api can be accessed via port 8481 with the following DNS name from within your cluster: vmcluster-victoria-metrics-cluster-vmselect.default.svc.cluster.local Get the VictoriaMetrics select service URL by running these commands in the same shell: export POD_NAME=$(kubectl get pods --namespace default -l "app=vmselect" -o jsonpath="{.items[0].metadata.name}") kubectl --namespace default port-forward $POD_NAME 8481 You need to specify select service URL into your Grafana: NOTE: you need to use the Prometheus Data Source Input this URL field into Grafana http:///select/0/prometheus/ for example - inside the Kubernetes cluster: http://vmcluster-victoria-metrics-cluster-vmselect.default.svc.cluster.local:8481/select/0/prometheus/" ``` Verify that the VictoriaMetrics cluster pods are up and running by executing the following command:
```console kubectl get pods | grep vmcluster ```
The expected output is: ```console vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-4mh9d 1/1 Running 0 2m28s vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-4ppl7 1/1 Running 0 2m28s vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-782qk 1/1 Running 0 2m28s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-4v4ws 1/1 Running 0 2m27s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-kwc7q 1/1 Running 0 2m28s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-v7pmk 1/1 Running 0 2m28s vmcluster-victoria-metrics-cluster-vmstorage-0 1/1 Running 0 2m27s vmcluster-victoria-metrics-cluster-vmstorage-1 1/1 Running 0 2m3s vmcluster-victoria-metrics-cluster-vmstorage-2 1/1 Running 0 99s ``` ## 3. Install vmagent from the Helm chart 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:
```yaml helm install vmagent vm/victoria-metrics-agent -f https://docs.victoriametrics.com/guides/guide-vmcluster-vmagent-values.yaml ```
Here is full file content `guide-vmcluster-vmagent-values.yaml` ```yaml remoteWriteUrls: - http://vmcluster-victoria-metrics-cluster-vminsert.default.svc.cluster.local:8480/insert/0/prometheus/ scrape_configs: - job_name: vmagent static_configs: - targets: ["localhost:8429"] - job_name: "kubernetes-apiservers" kubernetes_sd_configs: - role: endpoints scheme: https tls_config: ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt insecure_skip_verify: true bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token relabel_configs: - source_labels: [ __meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name, ] action: keep regex: default;kubernetes;https - job_name: "kubernetes-nodes" scheme: https tls_config: ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt insecure_skip_verify: true bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token kubernetes_sd_configs: - role: node relabel_configs: - action: labelmap regex: __meta_kubernetes_node_label_(.+) - target_label: __address__ replacement: kubernetes.default.svc:443 - source_labels: [__meta_kubernetes_node_name] regex: (.+) target_label: __metrics_path__ replacement: /api/v1/nodes/$1/proxy/metrics - job_name: "kubernetes-nodes-cadvisor" scheme: https tls_config: ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt insecure_skip_verify: true bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token kubernetes_sd_configs: - role: node relabel_configs: - action: labelmap regex: __meta_kubernetes_node_label_(.+) - target_label: __address__ replacement: kubernetes.default.svc:443 - source_labels: [__meta_kubernetes_node_name] regex: (.+) target_label: __metrics_path__ replacement: /api/v1/nodes/$1/proxy/metrics/cadvisor metric_relabel_configs: - action: replace source_labels: [pod] regex: '(.+)' target_label: pod_name replacement: '${1}' - action: replace source_labels: [container] regex: '(.+)' target_label: container_name replacement: '${1}' - action: replace target_label: name replacement: k8s_stub - action: replace source_labels: [id] regex: '^/system\.slice/(.+)\.service$' target_label: systemd_service_name replacement: '${1}' ``` * `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`. * The `metric_relabel_configs` section allows you to process Kubernetes metrics for the Grafana dashboard. Verify that `vmagent`'s pod is up and running by executing the following command:
```console kubectl get pods | grep vmagent ```
The expected output is: ```console vmagent-victoria-metrics-agent-57ddbdc55d-h4ljb 1/1 Running 0 13s ``` ## 4. Verifying HA of VictoraMetrics Cluster Run the following command to check that VictoriaMetrics services are up and running:
```console kubectl get pods | grep victoria-metrics ```
The expected output is: ```console vmagent-victoria-metrics-agent-57ddbdc55d-h4ljb 1/1 Running 0 75s vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-s8v7x 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-xlm9d 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vminsert-78b84d8cd9-xqxrh 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-7dg95 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-ck7qb 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vmselect-69c5f48bc6-jjqsl 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vmstorage-0 1/1 Running 0 89s vmcluster-victoria-metrics-cluster-vmstorage-1 1/1 Running 0 63s vmcluster-victoria-metrics-cluster-vmstorage-2 1/1 Running 0 34s ``` 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:
```console k get svc | grep vmselect ```
The expected output: ```console vmcluster-victoria-metrics-cluster-vmselect ClusterIP 10.88.2.69 8481/TCP 1m ``` Run the following command to make `vmselect`'s port accessable from the local machine:
```console kubectl port-forward svc/vmcluster-victoria-metrics-cluster-vmselect 8481:8481 ```
Execute the following command to get metrics via `curl`: ```console curl -sg 'http://127.0.0.1:8481/select/0/prometheus/api/v1/query_range?query=count(up{kubernetes_pod_name=~".*vmselect.*"})&start=-10m&step=1m' | jq ``` The expected output is: ```console { "status": "success", "isPartial": false, "data": { "resultType": "matrix", "result": [ { "metric": {}, "values": [ [ 1628065480.657, "3" ], [ 1628065540.657, "3" ], [ 1628065600.657, "3" ], [ 1628065660.657, "3" ], [ 1628065720.657, "3" ], [ 1628065780.657, "3" ], [ 1628065840.657, "3" ] ] } ] } } ``` * 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.

grafana explore

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:

The expected output is:

## 5. High Availability To test if High Availability works, we need to shutdown one of the `vmstorages`. To do this, run the following command:
```console kubectl scale sts vmcluster-victoria-metrics-cluster-vmstorage --replicas=2 ```
Verify that now we have two running `vmstorages` in the cluster by executing the following command:
```console kubectl get pods | grep vmstorage ```
The expected output is: ```console vmcluster-victoria-metrics-cluster-vmstorage-0 1/1 Running 0 44m vmcluster-victoria-metrics-cluster-vmstorage-1 1/1 Running 0 43m ``` Return to Grafana Explore and press the **Run query** button again. The expected output is:

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:

## 6. Final thoughts * We set up VictoriaMetrics for Kubernetes cluster with HA. * We collected metrics from running services and stored them in the VictoriaMetrics database. * We configured `dedup.minScrapeInterval` and `replicationFactor: 2` for VictoriaMetrics cluster for high availability purposes. * We tested and made sure that metrics are available even if one of `vmstorages` nodes was turned off.