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HazelcastOpsRequest

What is HazelcastOpsRequest

HazelcastOpsRequest is a Kubernetes Custom Resource Definitions (CRD). It provides declarative configuration for Hazelcast administrative operations like database version updating, horizontal scaling, vertical scaling, reconfigure TLS, restart, etc. in a Kubernetes native way.

HazelcastOpsRequest CRD Specifications

Like any official Kubernetes resource, a HazelcastOpsRequest has TypeMeta, ObjectMeta, Spec and Status sections.

Here, some sample HazelcastOpsRequest CRs for different administrative operations is given below.

Sample HazelcastOpsRequest for updating database version:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hzops-update-version
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: hz-prod
  updateVersion:
    targetVersion: 5.5.6

Sample HazelcastOpsRequest for horizontal scaling:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hazelcast-scale-up
  namespace: demo
spec:
  databaseRef:
    name: hz-prod
  type: HorizontalScaling
  horizontalScaling:
    hazelcast: 4

Sample HazelcastOpsRequest for vertical scaling:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hazelcast-vertical-scaling
  namespace: demo
spec:
  databaseRef:
    name: hz-prod
  type: VerticalScaling
  verticalScaling:
    hazelcast:
      resources:
        limits:
          cpu: 1
          memory: 2.5Gi
        requests:
          cpu: 1
          memory: 2.5Gi

Sample HazelcastOpsRequest for reconfiguring TLS:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hzops-add-tls
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: hz-prod
  tls:
    issuerRef:
      name: hz-issuer
      kind: Issuer
      apiGroup: "cert-manager.io"
    certificates:
      - alias: client
        subject:
          organizations:
            - hazelcast
          organizationalUnits:
            - client
  timeout: 5m
  apply: IfReady

Sample HazelcastOpsRequest for restart:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hazelcast-restart
  namespace: demo
spec:
  apply: IfReady
  databaseRef:
    name: hz-prod
  type: Restart

Sample HazelcastOpsRequest for reconfigure:

apiVersion: ops.kubedb.com/v1alpha1
kind: HazelcastOpsRequest
metadata:
  name: hz-reconfigure-custom-config
  namespace: demo
spec:
  apply: IfReady
  configuration:
    configSecret:
      name: hazelcast-custom-config
    applyConfig:
      hazelcast.yaml: |-
        hazelcast:
          persistence:
            enabled: true
            validation-timeout-seconds: 2500
            data-load-timeout-seconds: 3000
            auto-remove-stale-data: false        
      hazelcast-client.yaml: |-
        hazelcast-client: {}        
  databaseRef:
    name: hz-prod
  type: Reconfigure

Here, we are going to describe the various sections of a HazelcastOpsRequest crd.

HazelcastOpsRequest Spec

A HazelcastOpsRequest object has the following fields in the spec section.

spec.databaseRef

spec.databaseRef is a required field that point to the Hazelcast object for which the administrative operations will be performed. This field consists of the following sub-field:

• spec.databaseRef.name : specifies the name of the Hazelcast object.

spec.type

spec.type specifies the kind of operation that will be applied to the database. Currently, the following types of operations are allowed in HazelcastOpsRequest.

• UpdateVersion
• HorizontalScaling
• VerticalScaling
• VolumeExpansion
• Reconfigure
• ReconfigureTLS
• Restart

You can perform only one type of operation on a single HazelcastOpsRequest CR. For example, if you want to update your database and scale up its replica then you have to create two separate HazelcastOpsRequest. At first, you have to create a HazelcastOpsRequest for updating. Once it is completed, then you can create another HazelcastOpsRequest for scaling.

spec.updateVersion

If you want to update your Hazelcast version, you have to specify the spec.updateVersion section that specifies the desired version information. This field consists of the following sub-field:

• spec.updateVersion.targetVersion refers to a HazelcastVersion CR that contains the Hazelcast version information where you want to update.

You can only update between Hazelcast versions. KubeDB does not support downgrade for Hazelcast.

spec.horizontalScaling

If you want to scale-up or scale-down your Hazelcast cluster, you have to specify spec.horizontalScaling section. This field consists of the following sub-field:

• spec.horizontalScaling.member indicates the desired number of member nodes for Hazelcast cluster after scaling. For example, if your cluster currently has 3 member nodes and you want to add additional 2 member nodes then you have to specify 5 in spec.horizontalScaling.member field. Similarly, if you want to remove 1 node from the cluster, you have to specify 2 in spec.horizontalScaling.member field.

spec.verticalScaling

spec.verticalScaling is used to specify the new resources requirements to vertical scale the database. This field consists of the following sub-fields:

• spec.verticalScaling.member indicates the Hazelcast member resources. It has the below structure:

requests:
  memory: "2Gi"
  cpu: "1"
limits:
  memory: "2Gi"  
  cpu: "1"

Here, when you specify the resource request for Hazelcast member, KubeDB will create a new PetSet and StatefulSet with the new resource requirements and drop the old PetSet and StatefulSet.

spec.volumeExpansion

To expand the storage of the Hazelcast cluster, you have to specify spec.volumeExpansion section. This field consists of the following sub-field:

• spec.volumeExpansion.member indicates the desired size for the persistent volume claim of the member nodes.

All the volumes of member nodes will be expanded when the ops request type is VolumeExpansion.

spec.reconfigure

spec.reconfigure specifies the information of the custom configuration. This field consists of the following sub-field:

• spec.reconfigure.configSecret points to a secret in the same namespace of a Hazelcast resource, which contains the new custom configurations. If there are any configSecret is already associated with the database, the new custom configuration will be merged and will be applied to the database.

spec.reconfigureTLS

KubeDB supports reconfigure i.e. add, remove, update and rotation of TLS/SSL certificates for existing Hazelcast via a HazelcastOpsRequest. This field consists of the following sub-field:

• spec.reconfigureTLS.issuerRef specifies the issuer name, api group and kind of the desired issuer. For example,

issuerRef:
  apiGroup: cert-manager.io
  kind: Issuer
  name: hz-ca-issuer

• spec.reconfigureTLS.certificates specifies the certificates. For example,

certificates:
- alias: server
  subject:
    organizations:
    - hazelcast
    organizationalUnits:
    - server
- alias: client  
  subject:
    organizations:
    - hazelcast
    organizationalUnits:
    - client

• spec.reconfigureTLS.rotateCertificates specifies that we want to rotate the certificate of this database. Set it to true to rotate certificates.

• spec.reconfigureTLS.remove specifies that we want to remove tls of this database. Set it to true to remove tls.

spec.timeout

As we internally retry the ops request steps multiple times, This timeout field helps the users to specify the timeout for those steps of the ops request (in second). If a step doesn’t finish within the specified timeout, the ops request will result in failure.

spec.apply

This field controls the execution of obsRequest depending on the database state. It has two supported values: Always & IfReady. Use IfReady if you want to process the opsRequest only when the database is Ready. And use Always if you want to process the execution of opsReq irrespective of the Database state.

HazelcastOpsRequest Status

.status describes the current state and progress of the HazelcastOpsRequest operation. It has the following fields:

status.phase

status.phase indicates the overall phase of the operation for this HazelcastOpsRequest. It can have the following three values:

status.observedGeneration

status.observedGeneration shows the most recent generation observed by the HazelcastOpsRequest controller.

status.conditions

status.conditions is an array that specifies the conditions of different steps of HazelcastOpsRequest processing. Each condition entry has the following fields:

• types specifies the type of the condition. HazelcastOpsRequest has the following types of conditions:

• status specifies the status of the condition. It can be True, False or Unknown.
• lastTransitionTime specifies the last time the condition transitioned from one status to another.
• reason specifies the reason for the last transition of the condition.
• message provides a human readable message indicating details about the last transition.

Next Steps

• Learn about Hazelcast CRD.
• Deploy your first Hazelcast database with KubeDB by following the guide here.