NEXUS is an earth science data analytics application, and a component of the Apache Science Data Analytics Platform (SDAP).
The helm chart deploys all the required components of the NEXUS application (Spark webapp, Solr, Cassandra, Zookeeper, and optionally ingress components).
NEXUS needs the Spark Operator in order to run. Follow their instructions to install the Helm chart, or simply run:
$ kubectl create namespace spark-operator $ helm repo add incubator http://storage.googleapis.com/kubernetes-charts-incubator $ helm install incubator/sparkoperator --generate-name --namespace=spark-operator
NEXUS stores data in Cassandra and Solr. In order to have persistent storage, you need to have a Storage Class defined and have Persistent Volumes provisioned either manually or dynamically. See Persistent Volumes.
Tip: If you are using an NFS server as storage, you can use nfs-client-provisioner to dynamically provision persistent volumes on your NFS server.
First clone the NEXUS repository.
$ git clone https://github.com/apache/incubator-sdap-nexus.git
Then install the Helm chart.
$ kubectl create namespace sdap $ helm install nexus incubator-sdap-nexus/helm --namespace=sdap --dependency-update
Tip: It may take a few minutes for the
nexus-webapp-driverpod to start up because this depends on Solr and Cassandra being accessible.
Check that all the pods are up by running
kubectl get pods -n sdap, and make sure all pods have status
Running. If any pods have not started within a few minutes, you can look at its status with `kubectl describe pod -n sdap.
If you have installed the Helm chart locally with
ingressEnabled set to
ingressEnabled under Configuration), you can verify the installation by requesting the
list endpoint. If this returns an HTTP 200 response, Nexus is healthy.
$ curl localhost/nexus/list
If you have installed the Helm chart on a cloud provider, and/or have not enabled a loadbalancer with
ingressEnabled=true, you can temporarily port-forward the nexus-webapp port to see if the webapp responds.
First, on the Kubernetes cluster or jump host, create a port-forward to the
$ kubectl port-forward service/nexus-webapp -n sdap 8083:8083
Then open another shell on the same host and request the list endpoint through the forwarded port:
$ curl localhost:8083/list
Note: In this case the list endpoint is
/nexus/listbecause we are connecting to the
nexus-webappservice directly, instead of through an ingress rule.
If the request returns an HTTP 200 response, NEXUS is healthy. You can now close the first shell to disable the port-forward.
If one of the pods or deployment is not started, you can look at its status with:
kubectl describe pod <pod-name> -n sdap
To uninstall/delete the
$ helm delete nexus -n sdap
The command removes all the Kubernetes components associated with the chart and deletes the release.
There are two ways to override configuration values for the chart. The first is to use the
--set flag when installing the chart, for example:
$ helm install nexus incubator-sdap-nexus/helm --namespace=sdap --dependency-update --set cassandra.replicas=3 --set solr.replicas=3
The second way is to create a yaml file with overridden configuration values and pass it in with the
-f flag during chart installation.
# overridden-values.yml cassandra: replicas: 2 solr: replicas: 2
$ helm install nexus incubator-sdap-nexus/helm --namespace=sdap --dependency-update -f ~/overridden-values.yml
The following table lists the configurable parameters of the NEXUS chart and their default values. You can also look at
helm/values.yaml to see the available options.
Note: The default configuration values are tuned to run NEXUS in a local environment. Setting
ingressEnabled=truein addition will create a load balancer and expose NEXUS at
|Storage class to use for Cassandra, Solr, and Zookeeper. (Note that |
|Docker image and tag for the webapp|
|Number of cores on Spark driver|
|Maximum cores on Spark driver, in millicpus|
|Memory on Spark driver|
|Tolerations for Spark driver|
|Affinity (node or pod) for Spark driver|
|Number of cores on Spark workers|
|Number of Spark workers|
|Memory on Spark workers|
|Tolerations for Spark workers|
|Affinity (node or pod) for Spark workers|
|Number of Cassandra replicas|
|Storage per Cassandra replica|
|CPUs to request per Cassandra replica|
|Memory to request per Cassandra replica|
|CPU limit per Cassandra replica|
|Memory limit per Cassandra replica|
|Tolerations for Cassandra instances|
|Node selector for Cassandra instances|
|Number of Solr replicas (this should not be less than 2, or else solr-cloud will not be happy)|
|Storage per Solr replica|
|Heap per Solr replica|
|Memory to request per Solr replica|
|CPUs to request per Solr replica|
|Memory limit per Solr replica|
|CPU limit per Solr replica|
|Tolerations for Solr instances|
|Node selector for Solr instances|
|Number of zookeeper replicas. This should be an odd number greater than or equal to 3 in order to form a valid quorum.|
|Memory per zookeeper replica|
|CPUs per zookeeper replica|
|Storage per zookeeper replica|
|Tolerations for Zookeeper instances|
|Node selector for Zookeeper instances|
|IP or hostname to proxy |
|Limit the scope of the ingress controller to this namespace|
|Install ingress controller as Deployment, DaemonSet or Both|
|Create a front-facing controller service (this might be used for local or on-prem deployments)|
|Type of controller service to create|
|Use default backend component|
|Number of RabbitMQ replicas|
|Enable ingress resource for RabbitMQ Management console|
|Enable ingestion by deploying the Config Operator, Collection Manager, Granule Ingestion, and RabbitMQ|
|Number of Granule Ingester replicas|
|Docker image and tag for Granule Ingester|
|CPUs (request and limit) for each Granule Ingester replica|
|Memory (request and limit) for each Granule Ingester replica|
|Docker image and tag for Collection Manager|
|CPUs (request and limit) for the Collection Manager|
|Memory (request and limit) for the Collection Manager|
|Docker image and tag for Config Operator|
|An optional URL to an NFS server containing a directory where granule files are stored. If set, this NFS server will be mounted in the Collection Manager and Granule Ingester pods.|
|The path in the Collection Manager and Granule Ingester pods where granule files will be mounted. Important: the |
|Directory on either the local filesystem or an NFS mount where granule files are located. This directory will be mounted onto the Collection Manager and Granule Ingester at |
|URL to a Git repository containing a Collections Config file. The file should be at the root of the repository. The repository URL should be of the form |
|Branch to use when loading a Collections Config file from a Git repository.|
|An optional URL to a Solr database in which to store ingestion history. If this is not set, ingestion history will be stored in a directory instead, with the storage class configured by |
Sometimes you may wish to restrict pods to run on specific nodes, for example if you have “UAT” and “SIT” nodes within the same cluster. You can configure node selectors and tolerations for all the components, as in the following example:
webapp: distributed: driver: tolerations: - key: environment operator: Equal value: uat effect: NoExecute affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: environment operator: In values: - uat executor: tolerations: - key: environment operator: Equal value: uat effect: NoExecute affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: environment operator: In values: - uat cassandra: tolerations: - key: environment operator: Equal value: uat effect: NoExecute nodeSelector: environment: uat solr: tolerations: - key: environment operator: Equal value: uat effect: NoExecute nodeSelector: environment: uat zookeeper: tolerations: - key: environment operator: Equal value: uat effect: NoExecute nodeSelector: environment: uat
Note: The webapp supports
nodeSelectorbecause the Spark Operator has deprecated
nodeSelectorin favor of