Enable parallel pod management for Solr StatefulSets in Fusion 5

Goal

Allow Solr deployments in Fusion to use a custom podManagementPolicy like Parallel, improving pod restart efficiency even though the Solr Helm chart doesn’t directly support this setting.

Environment

• Fusion 5.9.13 and above

• Solr 9.6.1

• Kubernetes 1.32

• Amazon EKS (self-hosted)

• Applicable to Helm-based deployments
   

Guide

The Solr Helm chart does not expose podManagementPolicy as a configurable property. As a result, users cannot set this property directly via Helm templates or values files during Solr deployments.

Guidelines for Safe StatefulSet (STS) Deletion 

 

Deleting a StatefulSet (STS) without a proper plan for pod shutdown and recreation can lead to service disruption, as it automatically deletes its pods. 

kubectl get sts support-shared-595-solr -n support-shared-595 -o yaml > solr-sts-backup.yaml
kubectl scale sts support-shared-595-solr --replicas=0 -n support-shared-595
kubectl wait --for=delete pod -l app=solr -n support-shared-595 --timeout=300s

To deploy Solr with a custom podManagementPolicy, use the following approach:

Update Solr StatefulSet directly in kubernetes

• Backup the current Solr StatefulSet configuration:

kubectl get sts/<solr_statefulset_name> -n <namespace> -o yaml > new_sts.yaml

• Edit the YAML file:

  • Locate the podManagementPolicy field.

  • Change the value from:

podManagementPolicy: OrderedReady

• To:

podManagementPolicy: Parallel

• Delete the existing StatefulSet while preserving data volumes:

kubectl delete sts/<solr_statefulset_name> -n <namespace>

• Reapply the modified StatefulSet:

kubectl apply -f <path_to_file>/new_sts.yaml

5. Verify that the StatefulSet is now configured with podManagementPolicy: Parallel.

Note: Deleting a StatefulSet does not delete the associated PersistentVolumeClaims (PVCs). Data is preserved.

For example:

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: solr
  namespace: <fusion-namespace>
spec:
  serviceName: solr
  podManagementPolicy: Parallel
  replicas: 3
  selector:
    matchLabels:
      app: solr
  template:
    metadata:
      labels:
        app: solr
    spec:
      containers:
      - name: solr
        image: solr:9.6.1
        ports:
        - containerPort: 8983

Apply the YAML:

kubectl apply -f solr-statefulset.yaml

Update Helm chart to persist changes

By default, Fusion’s Solr Helm chart does not include podManagementPolicy. To manage this setting through Helm, update the chart templates. Ensure Helm does not overwrite the existing StatefulSet unless intentional.

• Edit the Solr chart template file (charts/solr/templates/statefulset.yaml) and add the following line under spec:

podManagementPolicy: {{ $.Values.podManagementPolicy | default "OrderedReady" }}

• Run a lint check:

helm lint fusion/charts/solr

• In your values.yaml, set:

solr:
  podManagementPolicy: Parallel

• Delete the existing Solr StatefulSet (PVCs are preserved):

kubectl delete sts/<solr_statefulset_name> -n <namespace>

• Recreate the StatefulSet with Helm:

helm upgrade <release_name> fusion -f fusion_values.yaml -n <namespace>

• Confirm that the StatefulSet manifest includes:

podManagementPolicy: Parallel

Considerations

• Parallel restarts can speed up upgrades and reduce downtime but may cause temporary instability if collections are actively indexed.

• Test the change in lower environments before applying to production.

• This setting cannot be updated in place on an existing StatefulSet. A delete and recreate process is required.