Backup Elasticsearch on Kubernetes


You can use the instructions on this page to create pre and post backup rules with PX-Backup, which take application-consistent backups for Elasticsearch on Kubernetes in production.

The Elasticsearch data directory is used prevent permanent data loss and is typically located at /user/share/elasticsearch/data inside the Kubernetes pod. This will also enable PX-Backup to back up and restore the data stored in this location.

Before using this guide, make sure and configure PVCs for elasticsearch-data. Use the below file as an example.

apiVersion: elasticsearch.k8s.elastic.co/v1
kind: Elasticsearch
metadata:
  name: elasticsearch
spec:
  version: 7.8.0
  nodeSets:
  - name: default
    count: 3
    podTemplate:
      metadata:
        labels:
          appname: "elastisearch-app"
      spec:
        containers:
          - name: elasticsearch
            volumeMounts:
            - name: elasticsearch-backups
              mountPath: /usr/share/elasticsearch/backups
        volumes:
        - name: elasticsearch-backups
          persistentVolumeClaim:
            claimName: elasticsearch-backups
    volumeClaimTemplates:
    - metadata:
        name: elasticsearch-data
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 5Gi
        storageClassName: elastic-pwx-storage-class
    config:
      node.master: true
      node.data: true
      node.ingest: true
      node.store.allow_mmap: false
      path.repo: ["/usr/share/elasticsearch/backups"]

Elasticsearch can also create a snapshot repository to store index snapshots produced by the internal snapshot and restore API. For this, the above template uses a Portworx shared volume and named elasticsearch-backups to create a shared file-system across all Elasticsearch nodes to be used to store the index snapshots.

Installation

Prerequisites

If you have not used Portworx, PX-Backup, or run Data services on Kubernetes it is a good idea to review the following information:

NOTE:

  • The templat above can not be used alone. Please follow pre-requisites from the following elastic on kubernetes operations guide.
  • The rules below will use a user name elastic and password specific to the environment. You will need to modify the rule to use your user name and password for your environment.
  • You should mount a PVC to the elasticsearch data directory. This is typically located at /user/share/elasticsearch/data.

Create rules for Elasticsearch

Create rules for Elasticsearch that will run both before and after the backup operation runs:

Create a pre-exec backup rule for Elasticsearch

For the pre-backup rule you will create a rule that performs multiple actions.

  • Freeze the index
  • Flush all indexes in Elasticsearch
  • Create an Elasticsearch index snapshot of all indexes

Create the rule.

  1. Navigate to SettingsRulesAdd New.
  2. Add a name for your Rule.
  3. Add the following app label:

    appname=elasticsearch-app
  4. Add the following action:

    curl -X POST -u "elastic:<password>" -k "https://elasticsearch-es-http:9200/customer/_freeze&pretty"
  5. Add the following additional action:

    curl -X PUT -u "elastic:<password>" -k "https://elasticsearch-es-http:9200/all/_flush&pretty"
  6. Add the following additional action:

    curl -X PUT -u "elastic:<password>" -k "https://elasticsearch-es-http:9200/_snapshot/es_backups/%3Csnapshot-$(uuidgen)-%7Bnow%2Fd%7D%3E?wait_for_completion=true&pretty"

    Select Elastic Pre Rule

Create a post-exec backup rule for Elasticsearch

Performing the _freeze and _flush operations on your index before calling the snapshot API ensures flexible and accurate restores by making sure the database isn’t currently being written into.

Since you performed a _freezeoperation when you created a backup, you must create a post exec rule to perform an _unfreeze operation. The steps below create a post-exec rule which runs _unfreeze on the customer index:

  1. Navigate to SettingsRulesAdd New.
  2. Add a name for your Rule.
  3. Add the following app label:

    appname=elasticsearch-app
  4. Add the following action:

    curl -X POST -u "elastic:<password>" -k "https://elasticsearch-es-http:9200/customer/_unfreeze&pretty"

    Select Elastic Post Rule

Note: If you deployed Elastic Stack using the elastic operator, ensure that you installed the crds and the required operator for elastic stack on the destination cluster as well. Also, when you backup and restore, ensure that you backup elastic operator along with the elastic namespace.

Elastic namespace

Associate the pre and post-exec rules with the Elasticsearch backup

Create a backup for your Elasticsearch application. Select the rules you created in the steps above from the pre-exec and post-exec drop downs:

Select elastic rules

Once you’ve filled out the backup form, click Create

Demo

Watch this short demo of the above information.


Last edited: Monday, Oct 3, 2022