⚠️ Repo Archive Notice

As of Nov 13, 2020, charts in this repo will no longer be updated. For more information, see the Helm Charts Deprecation and Archive Notice, and Update.

Cassandra

A Cassandra Chart for Kubernetes

DEPRECATION NOTICE

This chart is deprecated and no longer supported.

Install Chart

To install the Cassandra Chart into your Kubernetes cluster (This Chart requires persistent volume by default, you may need to create a storage class before install chart. To create storage class, see Persist data section)

bash

helm install --namespace "cassandra" -n "cassandra" incubator/cassandra

After installation succeeds, you can get a status of Chart

bash

helm status "cassandra"

If you want to delete your Chart, use this command

bash

helm delete  --purge "cassandra"

Upgrading

To upgrade your Cassandra release, simply run

bash

helm upgrade "cassandra" incubator/cassandra

0.12.0

This version fixes https://github.com/helm/charts/issues/7803 by removing mutable labels in spec.VolumeClaimTemplate.metadata.labels so that it is upgradable.

Until this version, in order to upgrade, you have to delete the Cassandra StatefulSet before upgrading:

bash

$ kubectl delete statefulset --cascade=false my-cassandra-release

Persist data

You need to create StorageClass before able to persist data in persistent volume. To create a StorageClass on Google Cloud, run the following

bash

kubectl create -f sample/create-storage-gce.yaml

And set the following values in values.yaml

yaml

persistence:
  enabled: true

If you want to create a StorageClass on other platform, please see documentation here https://kubernetes.io/docs/user-guide/persistent-volumes/

When running a cluster without persistence, the termination of a pod will first initiate a decommissioning of that pod. Depending on the amount of data stored inside the cluster this may take a while. In order to complete a graceful termination, pods need to get more time for it. Set the following values in values.yaml:

yaml

podSettings:
  terminationGracePeriodSeconds: 1800

Install Chart with specific cluster size

By default, this Chart will create a cassandra with 3 nodes. If you want to change the cluster size during installation, you can use --set config.cluster_size={value} argument. Or edit values.yaml

For example: Set cluster size to 5

bash

helm install --namespace "cassandra" -n "cassandra" --set config.cluster_size=5 incubator/cassandra/

Install Chart with specific resource size

By default, this Chart will create a cassandra with CPU 2 vCPU and 4Gi of memory which is suitable for development environment. If you want to use this Chart for production, I would recommend to update the CPU to 4 vCPU and 16Gi. Also increase size of max_heap_size and heap_new_size. To update the settings, edit values.yaml

Install Chart with specific node

Sometime you may need to deploy your cassandra to specific nodes to allocate resources. You can use node selector by edit nodes.enabled=true in values.yaml For example, you have 6 vms in node pools and you want to deploy cassandra to node which labeled as cloud.google.com/gke-nodepool: pool-db

Set the following values in values.yaml

yaml

nodes:
  enabled: true
  selector:
    nodeSelector:
      cloud.google.com/gke-nodepool: pool-db

Configuration

The following table lists the configurable parameters of the Cassandra chart and their default values.

Parameter	Description	Default
`image.repo`	`cassandra` image repository	`cassandra`
`image.tag`	`cassandra` image tag	`3.11.5`
`image.pullPolicy`	Image pull policy	`Always` if `imageTag` is `latest`, else `IfNotPresent`
`image.pullSecrets`	Image pull secrets	`nil`
`config.cluster_domain`	The name of the cluster domain.	`cluster.local`
`config.cluster_name`	The name of the cluster.	`cassandra`
`config.cluster_size`	The number of nodes in the cluster.	`3`
`config.seed_size`	The number of seed nodes used to bootstrap new clients joining the cluster.	`2`
`config.seeds`	The comma-separated list of seed nodes.	Automatically generated according to `.Release.Name` and `config.seed_size`
`config.num_tokens`	Initdb Arguments	`256`
`config.dc_name`	Initdb Arguments	`DC1`
`config.rack_name`	Initdb Arguments	`RAC1`
`config.endpoint_snitch`	Initdb Arguments	`SimpleSnitch`
`config.max_heap_size`	Initdb Arguments	`2048M`
`config.heap_new_size`	Initdb Arguments	`512M`
`config.ports.cql`	Initdb Arguments	`9042`
`config.ports.thrift`	Initdb Arguments	`9160`
`config.ports.agent`	The port of the JVM Agent (if any)	`nil`
`config.start_rpc`	Initdb Arguments	`false`
`configOverrides`	Overrides config files in /etc/cassandra dir	`{}`
`commandOverrides`	Overrides default docker command	`[]`
`argsOverrides`	Overrides default docker args	`[]`
`env`	Custom env variables	`{}`
`schedulerName`	Name of k8s scheduler (other than the default)	`nil`
`persistence.enabled`	Use a PVC to persist data	`true`
`persistence.storageClass`	Storage class of backing PVC	`nil` (uses alpha storage class annotation)
`persistence.accessMode`	Use volume as ReadOnly or ReadWrite	`ReadWriteOnce`
`persistence.size`	Size of data volume	`10Gi`
`resources`	CPU/Memory resource requests/limits	Memory: `4Gi`, CPU: `2`
`service.type`	k8s service type exposing ports, e.g. `NodePort`	`ClusterIP`
`service.annotations`	Annotations to apply to cassandra service	`""`
`podManagementPolicy`	podManagementPolicy of the StatefulSet	`OrderedReady`
`podDisruptionBudget`	Pod distruption budget	`{}`
`podAnnotations`	pod annotations for the StatefulSet	`{}`
`updateStrategy.type`	UpdateStrategy of the StatefulSet	`OnDelete`
`livenessProbe.initialDelaySeconds`	Delay before liveness probe is initiated	`90`
`livenessProbe.periodSeconds`	How often to perform the probe	`30`
`livenessProbe.timeoutSeconds`	When the probe times out	`5`
`livenessProbe.successThreshold`	Minimum consecutive successes for the probe to be considered successful after having failed.	`1`
`livenessProbe.failureThreshold`	Minimum consecutive failures for the probe to be considered failed after having succeeded.	`3`
`readinessProbe.initialDelaySeconds`	Delay before readiness probe is initiated	`90`
`readinessProbe.periodSeconds`	How often to perform the probe	`30`
`readinessProbe.timeoutSeconds`	When the probe times out	`5`
`readinessProbe.successThreshold`	Minimum consecutive successes for the probe to be considered successful after having failed.	`1`
`readinessProbe.failureThreshold`	Minimum consecutive failures for the probe to be considered failed after having succeeded.	`3`
`readinessProbe.address`	Address to use for checking node has joined the cluster and is ready.	`${POD_IP}`
`rbac.create`	Specifies whether RBAC resources should be created	`true`
`serviceAccount.create`	Specifies whether a ServiceAccount should be created	`true`
`serviceAccount.name`	The name of the ServiceAccount to use
`backup.enabled`	Enable backup on chart installation	`false`
`backup.schedule`	Keyspaces to backup, each with cron time
`backup.annotations`	Backup pod annotations	iam.amazonaws.com/role: `cain`
`backup.image.repository`	Backup image repository	`maorfr/cain`
`backup.image.tag`	Backup image tag	`0.6.0`
`backup.extraArgs`	Additional arguments for cain	`[]`
`backup.env`	Backup environment variables	AWS_REGION: `us-east-1`
`backup.resources`	Backup CPU/Memory resource requests/limits	Memory: `1Gi`, CPU: `1`
`backup.destination`	Destination to store backup artifacts	`s3://bucket/cassandra`
`backup.google.serviceAccountSecret`	Secret containing credentials if GCS is used as destination
`exporter.enabled`	Enable Cassandra exporter	`false`
`exporter.servicemonitor.enabled`	Enable ServiceMonitor for exporter	`true`
`exporter.servicemonitor.additionalLabels`	Additional labels for Service Monitor	`{}`
`exporter.image.repo`	Exporter image repository	`criteord/cassandra_exporter`
`exporter.image.tag`	Exporter image tag	`2.0.2`
`exporter.port`	Exporter port	`5556`
`exporter.jvmOpts`	Exporter additional JVM options
`exporter.resources`	Exporter CPU/Memory resource requests/limits	`{}`
`extraContainers`	Sidecar containers for the pods	`[]`
`extraVolumes`	Additional volumes for the pods	`[]`
`extraVolumeMounts`	Extra volume mounts for the pods	`[]`
`affinity`	Kubernetes node affinity	`{}`
`tolerations`	Kubernetes node tolerations	`[]`

Scale cassandra

When you want to change the cluster size of your cassandra, you can use the helm upgrade command.

bash

helm upgrade --set config.cluster_size=5 cassandra incubator/cassandra

Get cassandra status

You can get your cassandra cluster status by running the command

bash

kubectl exec -it --namespace cassandra $(kubectl get pods --namespace cassandra -l app=cassandra-cassandra -o jsonpath='{.items[0].metadata.name}') nodetool status

Output

bash

Datacenter: asia-east1
======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens       Owns (effective)  Host ID                               Rack
UN  10.8.1.11  108.45 KiB  256          66.1%             410cc9da-8993-4dc2-9026-1dd381874c54  a
UN  10.8.4.12  84.08 KiB  256          68.7%             96e159e1-ef94-406e-a0be-e58fbd32a830  c
UN  10.8.3.6   103.07 KiB  256          65.2%             1a42b953-8728-4139-b070-b855b8fff326  b

Benchmark

You can use cassandra-stress tool to run the benchmark on the cluster by the following command

bash

kubectl exec -it --namespace cassandra $(kubectl get pods --namespace cassandra -l app=cassandra-cassandra -o jsonpath='{.items[0].metadata.name}') cassandra-stress

Example of cassandra-stress argument

Run both read and write with ration 9:1
Operator total 1 million keys with uniform distribution
Use QUORUM for read/write
Generate 50 threads
Generate result in graph
Use NetworkTopologyStrategy with replica factor 2

bash

cassandra-stress mixed ratio\(write=1,read=9\) n=1000000 cl=QUORUM -pop dist=UNIFORM\(1..1000000\) -mode native cql3 -rate threads=50 -log file=~/mixed_autorate_r9w1_1M.log -graph file=test2.html title=test revision=test2 -schema "replication(strategy=NetworkTopologyStrategy, factor=2)"