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Reconfigure Elasticsearch Topology Cluster

This guide will show you how to use KubeDB Ops-manager operator to reconfigure an Elasticsearch Topology cluster.

Before You Begin

To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace/demo created

Note: YAML files used in this tutorial are stored in docs/examples/elasticsearch directory of kubedb/docs repository.

Now, we are going to deploy an Elasticsearch Topology cluster using a supported version by KubeDB operator. Then we are going to apply ElasticsearchOpsRequest to reconfigure its configuration.

Prepare Elasticsearch Topology Cluster

Now, we are going to deploy an Elasticsearch topology cluster with version xpack-8.19.9.

Deploy Elasticsearch

At first, we will create a secret with role-prefixed configuration files. In a topology cluster, you can target specific node roles by prefixing the filename with the role name (e.g., master-elasticsearch.yml applies only to master nodes, data-elasticsearch.yml applies only to data nodes).

master-elasticsearch.yml:

cluster.max_shards_per_node: 2000

data-elasticsearch.yml:

indices.query.bool.max_clause_count: 2048

ingest-elasticsearch.yml:

http.max_content_length: 200mb

Here, cluster.max_shards_per_node is set to 2000 (default 1000) for master nodes, indices.query.bool.max_clause_count is set to 2048 (default 1024) for data nodes, and http.max_content_length is set to 200mb (default 100mb) for ingest nodes.

Let’s create a k8s secret containing the above configuration where the file name will be the key and the file-content as the value:

apiVersion: v1
kind: Secret
metadata:
  name: es-topology-custom-config
  namespace: demo
stringData:
  master-elasticsearch.yml: |-
    cluster.max_shards_per_node: 2000    
  data-elasticsearch.yml: |-
    indices.query.bool.max_clause_count: 2048    
  ingest-elasticsearch.yml: |-
    http.max_content_length: 200mb    

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2026.4.27/docs/examples/elasticsearch/reconfigure/es-topology-custom-config.yaml
secret/es-topology-custom-config created

In this section, we are going to create an Elasticsearch object specifying spec.configuration.secretName field to apply this custom configuration. Below is the YAML of the Elasticsearch CR that we are going to create,

apiVersion: kubedb.com/v1
kind: Elasticsearch
metadata:
  name: es-topology
  namespace: demo
spec:
  version: xpack-8.19.9
  enableSSL: true
  configuration:
    secretName: es-topology-custom-config
  topology:
    master:
      replicas: 1
      storage:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
        storageClassName: standard
    data:
      replicas: 2
      storage:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
        storageClassName: standard
    ingest:
      replicas: 1
      storage:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
        storageClassName: standard
  storageType: Durable
  deletionPolicy: WipeOut

Let’s create the Elasticsearch CR we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2026.4.27/docs/examples/elasticsearch/reconfigure/es-topology.yaml
elasticsearch.kubedb.com/es-topology created

Now, wait until es-topology has status Ready. i.e,

$ kubectl get es -n demo -w
NAME          VERSION          STATUS         AGE
es-topology   xpack-8.19.9    Provisioning   0s
es-topology   xpack-8.19.9    Provisioning   24s
.
.
es-topology   xpack-8.19.9    Ready          92s

Now, we will check if the Elasticsearch has started with the custom configuration we have provided.

Exec into the master node and check the cluster setting:

$ kubectl exec -it -n demo es-topology-master-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.cluster&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_shards_per_node
          "max_shards_per_node" : "2000",

Exec into a data node and check the index settings:

$ kubectl exec -it -n demo es-topology-data-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.indices&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_clause_count
              "max_clause_count" : "2048"
              "max_clause_count" : "2048"

Exec into the ingest node and check the HTTP settings:

$ kubectl exec -it -n demo es-topology-ingest-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.http&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_content_length
          "max_content_length" : "200mb",

Here, we can see that our given configurations are applied to the respective node roles.

Reconfigure using new config secret

Now we will reconfigure this cluster to update cluster.max_shards_per_node to 3000 for master nodes, indices.query.bool.max_clause_count to 4096 for data nodes, and http.max_content_length to 300mb for ingest nodes.

Update our configuration files with the new values.

master-elasticsearch.yml:

cluster.max_shards_per_node: 3000

data-elasticsearch.yml:

indices.query.bool.max_clause_count: 4096

ingest-elasticsearch.yml:

http.max_content_length: 300mb

Then, we will create a new secret with these configuration files.

apiVersion: v1
kind: Secret
metadata:
  name: new-es-topology-custom-config
  namespace: demo
stringData:
  master-elasticsearch.yml: |-
    cluster.max_shards_per_node: 3000    
  data-elasticsearch.yml: |-
    indices.query.bool.max_clause_count: 4096    
  ingest-elasticsearch.yml: |-
    http.max_content_length: 300mb    

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2026.4.27/docs/examples/elasticsearch/reconfigure/new-es-topology-custom-config.yaml
secret/new-es-topology-custom-config created

Create ElasticsearchOpsRequest

Now, we will use this secret to replace the previous secret using an ElasticsearchOpsRequest CR. The ElasticsearchOpsRequest yaml is given below,

apiVersion: ops.kubedb.com/v1alpha1
kind: ElasticsearchOpsRequest
metadata:
  name: esops-reconfigure-topology
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: es-topology
  configuration:
    configSecret:
      name: new-es-topology-custom-config
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are reconfiguring es-topology database.
  • spec.type specifies that we are performing Reconfigure on our database.
  • spec.configuration.configSecret.name specifies the name of the new secret.

Let’s create the ElasticsearchOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2026.4.27/docs/examples/elasticsearch/reconfigure/es-reconfigure-update-topology.yaml
elasticsearchopsrequest.ops.kubedb.com/esops-reconfigure-topology created

Verify the new configuration is working

If everything goes well, KubeDB Ops-manager operator will update the configSecret of Elasticsearch object.

Let’s wait for ElasticsearchOpsRequest to be Successful. Run the following command to watch ElasticsearchOpsRequest CR,

$ kubectl get elasticsearchopsrequests -n demo
NAME                         TYPE          STATUS       AGE
esops-reconfigure-topology   Reconfigure   Successful   4m55s

We can see from the above output that the ElasticsearchOpsRequest has succeeded. If we describe the ElasticsearchOpsRequest we will get an overview of the steps that were followed to reconfigure the database.

$ kubectl describe elasticsearchopsrequest -n demo esops-reconfigure-topology
Name:         esops-reconfigure-topology
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ElasticsearchOpsRequest
Metadata:
  Creation Timestamp:  2026-06-15T11:13:59Z
  Generation:          1
  Resource Version:    434719
  UID:                 a050a578-420c-4bb8-a390-3b32b369ec65
Spec:
  Apply:  IfReady
  Configuration:
    Config Secret:
      Name:   new-es-topology-custom-config
    Restart:  auto
  Database Ref:
    Name:       es-topology
  Max Retries:  1
  Timeout:      5m
  Type:         Reconfigure
Status:
  Conditions:
    Last Transition Time:  2026-06-15T11:13:59Z
    Message:               Elasticsearch ops request is Reconfiguring
    Observed Generation:   1
    Reason:                Reconfigure
    Status:                True
    Type:                  Reconfigure
    Last Transition Time:  2026-06-15T11:14:09Z
    Message:               Successfully updated petSets
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2026-06-15T11:14:19Z
    Message:               pod exists; ConditionStatus:True; PodName:es-topology-ingest-0
    Observed Generation:   1
    Status:                True
    Type:                  PodExists--es-topology-ingest-0
    Last Transition Time:  2026-06-15T11:14:19Z
    Message:               create es client; ConditionStatus:True; PodName:es-topology-ingest-0
    Observed Generation:   1
    Status:                True
    Type:                  CreateEsClient--es-topology-ingest-0
    Last Transition Time:  2026-06-15T11:14:19Z
    Message:               evict pod; ConditionStatus:True; PodName:es-topology-ingest-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--es-topology-ingest-0
    Last Transition Time:  2026-06-15T11:14:59Z
    Message:               create es client; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CreateEsClient
    Last Transition Time:  2026-06-15T11:14:34Z
    Message:               pod exists; ConditionStatus:True; PodName:es-topology-data-0
    Observed Generation:   1
    Status:                True
    Type:                  PodExists--es-topology-data-0
    Last Transition Time:  2026-06-15T11:14:34Z
    Message:               create es client; ConditionStatus:True; PodName:es-topology-data-0
    Observed Generation:   1
    Status:                True
    Type:                  CreateEsClient--es-topology-data-0
    Last Transition Time:  2026-06-15T11:14:34Z
    Message:               evict pod; ConditionStatus:True; PodName:es-topology-data-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--es-topology-data-0
    Last Transition Time:  2026-06-15T11:14:49Z
    Message:               pod exists; ConditionStatus:True; PodName:es-topology-data-1
    Observed Generation:   1
    Status:                True
    Type:                  PodExists--es-topology-data-1
    Last Transition Time:  2026-06-15T11:14:49Z
    Message:               create es client; ConditionStatus:True; PodName:es-topology-data-1
    Observed Generation:   1
    Status:                True
    Type:                  CreateEsClient--es-topology-data-1
    Last Transition Time:  2026-06-15T11:14:49Z
    Message:               evict pod; ConditionStatus:True; PodName:es-topology-data-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--es-topology-data-1
    Last Transition Time:  2026-06-15T11:15:04Z
    Message:               pod exists; ConditionStatus:True; PodName:es-topology-master-0
    Observed Generation:   1
    Status:                True
    Type:                  PodExists--es-topology-master-0
    Last Transition Time:  2026-06-15T11:15:04Z
    Message:               create es client; ConditionStatus:True; PodName:es-topology-master-0
    Observed Generation:   1
    Status:                True
    Type:                  CreateEsClient--es-topology-master-0
    Last Transition Time:  2026-06-15T11:15:04Z
    Message:               evict pod; ConditionStatus:True; PodName:es-topology-master-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--es-topology-master-0
    Last Transition Time:  2026-06-15T11:15:14Z
    Message:               Successfully restarted all nodes
    Observed Generation:   1
    Reason:                RestartNodes
    Status:                True
    Type:                  RestartNodes
    Last Transition Time:  2026-06-15T11:15:15Z
    Message:               Successfully completed the modification process.
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                                Age    From                         Message
  ----     ------                                                                ----   ----                         -------
  Normal   PauseDatabase                                                         4m47s  KubeDB Ops-manager Operator  Pausing Elasticsearch demo/es-topology
  Warning  pod exists; ConditionStatus:True; PodName:es-topology-ingest-0        4m29s  KubeDB Ops-manager Operator  pod exists; ConditionStatus:True; PodName:es-topology-ingest-0
  Warning  create es client; ConditionStatus:True; PodName:es-topology-ingest-0  4m29s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True; PodName:es-topology-ingest-0
  Warning  evict pod; ConditionStatus:True; PodName:es-topology-ingest-0         4m29s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:es-topology-ingest-0
  Warning  create es client; ConditionStatus:False                               4m24s  KubeDB Ops-manager Operator  create es client; ConditionStatus:False
  Warning  create es client; ConditionStatus:True                                4m19s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True
  Warning  pod exists; ConditionStatus:True; PodName:es-topology-data-0          4m14s  KubeDB Ops-manager Operator  pod exists; ConditionStatus:True; PodName:es-topology-data-0
  Warning  create es client; ConditionStatus:True; PodName:es-topology-data-0    4m14s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True; PodName:es-topology-data-0
  Warning  evict pod; ConditionStatus:True; PodName:es-topology-data-0           4m14s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:es-topology-data-0
  Warning  create es client; ConditionStatus:False                               4m9s   KubeDB Ops-manager Operator  create es client; ConditionStatus:False
  Warning  create es client; ConditionStatus:True                                4m4s   KubeDB Ops-manager Operator  create es client; ConditionStatus:True
  Warning  pod exists; ConditionStatus:True; PodName:es-topology-data-1          3m59s  KubeDB Ops-manager Operator  pod exists; ConditionStatus:True; PodName:es-topology-data-1
  Warning  create es client; ConditionStatus:True; PodName:es-topology-data-1    3m59s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True; PodName:es-topology-data-1
  Warning  evict pod; ConditionStatus:True; PodName:es-topology-data-1           3m59s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:es-topology-data-1
  Warning  create es client; ConditionStatus:False                               3m54s  KubeDB Ops-manager Operator  create es client; ConditionStatus:False
  Warning  create es client; ConditionStatus:True                                3m49s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True
  Warning  pod exists; ConditionStatus:True; PodName:es-topology-master-0        3m44s  KubeDB Ops-manager Operator  pod exists; ConditionStatus:True; PodName:es-topology-master-0
  Warning  create es client; ConditionStatus:True; PodName:es-topology-master-0  3m44s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True; PodName:es-topology-master-0
  Warning  evict pod; ConditionStatus:True; PodName:es-topology-master-0         3m44s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:es-topology-master-0
  Warning  create es client; ConditionStatus:True                                3m39s  KubeDB Ops-manager Operator  create es client; ConditionStatus:True
  Normal   RestartNodes                                                          3m34s  KubeDB Ops-manager Operator  Successfully restarted all nodes
  Normal   Successful                                                            3m33s  KubeDB Ops-manager Operator  Successfully reconfigured all elasticsearch nodes.

Now let’s exec into a master node, a data node, and the ingest node to verify the new configuration.

$ kubectl exec -it -n demo es-topology-master-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.cluster&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_shards_per_node
          "max_shards_per_node" : "3000",

$ kubectl exec -it -n demo es-topology-data-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.indices&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_clause_count
              "max_clause_count" : "4096"
              "max_clause_count" : "4096"

$ kubectl exec -it -n demo es-topology-ingest-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.http&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_content_length
          "max_content_length" : "300mb",

As we can see, the values have been updated on their respective node roles. So the reconfiguration of the cluster is successful.

Reconfigure using apply config

Now we will reconfigure this cluster again using the applyConfig field. This will merge the new config into the existing secret without requiring a new secret.

Create ElasticsearchOpsRequest

apiVersion: ops.kubedb.com/v1alpha1
kind: ElasticsearchOpsRequest
metadata:
  name: esops-reconfigure-apply-topology
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: es-topology
  configuration:
    applyConfig:
      master-elasticsearch.yml: |
        cluster.max_shards_per_node: 4000        
      data-elasticsearch.yml: |
        indices.query.bool.max_clause_count: 8192        
      ingest-elasticsearch.yml: |
        http.max_content_length: 400mb        
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are reconfiguring es-topology cluster.
  • spec.type specifies that we are performing Reconfigure on Elasticsearch.
  • spec.configuration.applyConfig specifies the new configuration that will be merged into the existing secret.

Let’s create the ElasticsearchOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2026.4.27/docs/examples/elasticsearch/reconfigure/es-reconfigure-apply-topology.yaml
elasticsearchopsrequest.ops.kubedb.com/esops-reconfigure-apply-topology created

Verify the new configuration is working

Let’s wait for ElasticsearchOpsRequest to be Successful.

$  kubectl get elasticsearchopsrequests -n demo esops-reconfigure-apply-topology
NAME                               TYPE          STATUS       AGE
esops-reconfigure-apply-topology   Reconfigure   Successful   6m52s

Now let’s verify the updated values on each node role.

$ kubectl exec -it -n demo es-topology-master-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.cluster&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_shards_per_node
          "max_shards_per_node" : "4000",

$ kubectl exec -it -n demo es-topology-data-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.indices&pretty" --user "elastic:$ELASTIC_USER_PASSWORD" | grep max_clause_count
              "max_clause_count" : "8192"
              "max_clause_count" : "8192"

$ kubectl exec -it -n demo es-topology-ingest-0 -c elasticsearch -- curl -k -XGET "https://localhost:9200/_nodes/settings?filter_path=nodes.*.settings.http&pretty" --user "elastic:X4am_*ihVy~M)m0j" | grep max_content_length
          "max_content_length" : "400mb",

As we can see, cluster.max_shards_per_node has been changed from 3000 to 4000 on master nodes, indices.query.bool.max_clause_count has been changed from 4096 to 8192 on data nodes, and http.max_content_length has been changed from 300mb to 400mb on ingest nodes. So the reconfiguration using the applyConfig field is successful.

Cleaning Up

To clean up the Kubernetes resources created by this tutorial, run:

kubectl delete es -n demo es-topology
kubectl delete elasticsearchopsrequest -n demo esops-reconfigure-apply-topology esops-reconfigure-topology
kubectl delete secret -n demo es-topology-custom-config new-es-topology-custom-config
kubectl delete ns demo

Next Steps

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