SearchVarnish Helm Chart
Varnish Cluster is a solution for increasing cache hit rate in a Varnish Enterprise deployment and reducing load on the origin service. It’s dynamic, scalable, and can be enabled with just a few lines of VCL.
This guide covers how to enable a dynamic cluster using the official Varnish Enterprise Helm chart.
The Varnish Enterprise Installation Guide and the official Varnish Enterprise Helm chart must be used to install and deploy Varnish Enterprise.
The official Varnish Enterprise Helm charts now provide the simplest way to
activate clustering. There is no longer a requirement to generate a cluster token or manually configure an override file. Simply setting cluster.enabled to true
in your values.yaml file will automatically handle the configurations:
cluster:
enabled: true # false by default; turns on clustering
# trace: true # false by default; temporarily set to true for debugging
This enables clustering and allows pods to shard requests between each other. For further details, refer to the Helm configuration API.
Apply the changes defined in the override file on top of the chart defaults:
helm upgrade varnish-enterprise varnish/varnish-enterprise -f values.yaml
The following command displays metrics such as cluster_stats.error_token and cluster_stats.self_identified:
kubectl exec -it <any-pod-name> -- varnishstat -1 -f 'KVSTORE.cluster_stats.*'
Refer to the cluster observability section for more details about the metrics.
Run the following command to verify you have one backend entry per peer (including self).
kubectl exec -it <any-pod-name> -- varnishadm backend.list '*.*'
Cluster logs are prefixed with Cluster: and are logged with the VCL_Log tag. They can be observed with the following varnishlog command:
$ kubectl exec -it <any-pod-name> -- varnishlog -g raw -q 'VCL_Log ~ "^Cluster:"' -i VCL_Log
146 VCL_Log b Cluster: Not self-routing, this is a primary node
...
18 VCL_Log b Cluster: Self-routing to primary node