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PerconaXtraDBOpsRequest

What is PerconaXtraDBOpsRequest

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

PerconaXtraDBOpsRequest CRD Specifications

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

Here, some sample PerconaXtraDBOpsRequest CRs for different administrative operations is given below:

Sample PerconaXtraDBOpsRequest for updating database:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-version-update
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: sample-pxc
  updateVersion:
    targetVersion: 8.0.26
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample PerconaXtraDBOpsRequest Objects for Horizontal Scaling of database cluster:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-scale-horizontal
  namespace: demo
spec:
  type: HorizontalScaling
  databaseRef:
    name: sample-pxc
  horizontalScaling:
    member : 5
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample PerconaXtraDBOpsRequest Objects for Vertical Scaling of the database cluster:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-scale-vertical
  namespace: demo
spec:
  type: VerticalScaling  
  databaseRef:
    name: sample-pxc
  verticalScaling:
    perconaxtradb:
      resources:
        requests:
          memory: "600Mi"
          cpu: "0.1"
        limits:
          memory: "600Mi"
          cpu: "0.1"
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample PerconaXtraDBOpsRequest Objects for Reconfiguring PerconaXtraDB Database:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-reconfigure
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: sample-pxc
  configuration:   
    applyConfig:
      my-apply.cnf: |-
        max_connections = 300
        read_buffer_size = 1234567        
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample PerconaXtraDBOpsRequest Objects for Volume Expansion of PerconaXtraDB:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-volume-expansion
  namespace: demo
spec:
  type: VolumeExpansion  
  databaseRef:
    name: sample-pxc
  volumeExpansion:   
    mode: "Online"
    perconaxtradb: 2Gi
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample PerconaXtraDBOpsRequest Objects for Reconfiguring TLS of the database:

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-recon-tls-add
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: sample-pxc
  tls:
    requireSSL: true
    issuerRef:
      apiGroup: cert-manager.io
      kind: Issuer
      name: px-issuer
    certificates:
    - alias: server
      subject:
        organizations:
        - kubedb:server
      dnsNames:
      - localhost
      ipAddresses:
      - "127.0.0.1"

apiVersion: ops.kubedb.com/v1alpha1
kind: PerconaXtraDBOpsRequest
metadata:
  name: px-recon-tls-rotate
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: sample-pxc
  tls:
    rotateCertificates: true

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

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

spec.databaseRef

spec.databaseRef is a required field that point to the PerconaXtraDB 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 PerconaXtraDB 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 PerconaXtraDBOpsRequest.

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

You can perform only one type of operation on a single PerconaXtraDBOpsRequest CR. For example, if you want to update your database and scale up its replica then you have to create two separate PerconaXtraDBOpsRequest. At first, you have to create a PerconaXtraDBOpsRequest for updating. Once it is completed, then you can create another PerconaXtraDBOpsRequest for scaling. You should not create two PerconaXtraDBOpsRequest simultaneously.

spec.updateVersion

If you want to update your PerconaXtraDB 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 PerconaXtraDBVersion CR that contains the PerconaXtraDB version information where you want to update.

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

spec.horizontalScaling

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

• spec.horizontalScaling.member indicates the desired number of nodes for PerconaXtraDB cluster after scaling. For example, if your cluster currently has 4 nodes, and you want to add additional 2 nodes then you have to specify 6 in spec.horizontalScaling.member field. Similarly, if you want to remove one node from the cluster, you have to specify 3 in spec.horizontalScaling. field.

spec.verticalScaling

spec.verticalScaling is a required field specifying the information of PerconaXtraDB resources like cpu, memory etc that will be scaled. This field consists of the following sub-field:

• spec.verticalScaling.perconaxtradb indicates the desired resources for PerconaXtraDB standalone or cluster after scaling.
• spec.verticalScaling.exporter indicates the desired resources for the exporter container.
• spec.verticalScaling.coordinator indicates the desired resources for the coordinator container.

All of them has the below structure:

requests:
  memory: "200Mi"
  cpu: "0.1"
limits:
  memory: "300Mi"
  cpu: "0.2"

Here, when you specify the resource request, the scheduler uses this information to decide which node to place the container of the Pod on and when you specify a resource limit for the container, the kubelet enforces those limits so that the running container is not allowed to use more of that resource than the limit you set. You can found more details from here.

spec.volumeExpansion

To use the volume expansion feature the storage class must support volume expansion

If you want to expand the volume of your PerconaXtraDB standalone or cluster, you have to specify spec.volumeExpansion section. This field consists of the following sub-field:

• spec.volumeExpansion.perconaxtradb indicates the desired size for the persistent volume of a PerconaXtraDB.
• spec.volumeExpansion.mode indicates the mode of volume expansion. It can be online or offline based on the storage class.

All of them refer to Quantity types of Kubernetes.

Example usage of this field is given below:

spec:
  volumeExpansion:
    perconaxtradb: "2Gi"

This will expand the volume size of all the perconaxtradb nodes to 2 GB.

spec.configuration

If you want to reconfigure your Running PerconaXtraDB cluster with new custom configuration, you have to specify spec.configuration section. This field consists of the following sub-fields:

• configSecret points to a secret in the same namespace of a PerconaXtraDB resource, which contains the new custom configurations. If there are any configSecret set before in the database, this secret will replace it.
• applyConfig contains the new custom config as a string which will be merged with the previous configuration.
• removeCustomConfig reomoves all the custom configs of the PerconaXtraDB server.

spec.tls

If you want to reconfigure the TLS configuration of your database i.e. add TLS, remove TLS, update issuer/cluster issuer or Certificates and rotate the certificates, you have to specify spec.tls section. This field consists of the following sub-field:

• spec.tls.issuerRef specifies the issuer name, kind and api group.
• spec.tls.certificates specifies the certificates. You can learn more about this field from here.
• spec.tls.rotateCertificates specifies that we want to rotate the certificate of this database.
• spec.tls.remove specifies that we want to remove tls from this database.

PerconaXtraDBOpsRequest Status

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

status.phase

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

status.observedGeneration

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

status.conditions

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

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

• The status field is a string, with possible values True, False, and Unknown.
  • status will be True if the current transition succeeded.
  • status will be False if the current transition failed.
  • status will be Unknown if the current transition was denied.
• The message field is a human-readable message indicating details about the condition.
• The reason field is a unique, one-word, CamelCase reason for the condition’s last transition.
• The lastTransitionTime field provides a timestamp for when the operation last transitioned from one state to another.
• The observedGeneration shows the most recent condition transition generation observed by the controller.