HA Multi-AZ Setup

If you need High Availability(HA) for a Kloudfuse cluster, you have the option of deploying it across multiple availability zones (multi-AZ). A multi-AZ setup minimizes downtime and maintains observability workflows in the event of a zone failure. Each zone must have at least 2 pods to run the supported components.

Benefits of Multi-AZ Deployment

• Protects against zone-level failures
• Ensures service continuity
• Balances workload across zones
• Aligns with SRE best practices

Prerequisites

Before you begin:

• Kubernetes Cluster Infrastructure

  • A fresh installation. A Kloudfuse cluster cannot be upgraded to a Multi-AZ setup.
  • Nodes to be set up across 3 availability zones (required)
  • Each availability zone must have an equal number of nodes (required)
  • The total number of nodes must be a multiple of 6 (required)
  • Nodes cannot have additional taints outside what is used by Kloudfuse (required) Additional taints will cause validations to fail and those will not be used

• Cloud Managed PostgreSQL instance

  • Cloud Provider managed PostgreSQL instance:
    • AWS RDS
    • GCP Cloud SQL
    • Azure Database for PostgreSQL
    • PostgreSQL must be available to all 3 availability zones.
    • PostgreSQL version 14.11+
    • Kubernetes Secret with PostgreSQL credentials

• AWS-only

  • A NLB and Kloudfuse DNS mapping
  • Use a NLB (Network Load Balancer) for Kloudfuse DNS mapping. Elastic IPs are AZ-specific, the DNS for the Kloudfuse endpoint must be a CNAME pointing to the NLB DNS to ensure traffic routing during a zone failure.

Step 1: Configure Helm Values

In the custom_values.yaml, configure the following fields:

global:
  cloudProvider: <aws | gcp | azure>
  numNodes: <Total number of nodes across all zones>
  multiAzDeployment:
    enabled: true
  configDB:
    host: <Postgres host for configDB>
  orchestratorDB:
    host: <Postgres host for orchestratorDB>

installKfusePgCredentials: false

This configuration ensures Kloudfuse uses external PostgreSQL and skips deploying its own credentials secret.

Step 2: Disable Embedded PostgreSQL

To use cloud-managed PostgreSQL, disable the internal PostgreSQL services:

ingester:
  postgresql:
    enabled: false

kfuse-configdb:
  enabled: false

Step 3: Automatic Scaling and Anti-Affinity Rules

When multiAzDeployment.enabled is set to true, Kloudfuse will automatically:

• Adjusts replicaCount for services based on global.numNodes
• Applies pod anti-affinity rules to distribute replicas across availability zones

Do not manually set replicaCount for most services.

Service Behavior in Multi-AZ Mode

These services will auto-scale based on the number of nodes that are being used in the cluster.

• advance-functions-service
• events-query-service
• ingester
• kafka
• llm-evaluation-service
• llm-query-service
• logs-parser
• logs-query-service
• logs-transformer
• kfuse-observability-agent
• kfuse-vector
• metrics-transformer
• pinot
• query-service
• rum-query-service
• trace-query-service
• trace-transformer
• zapper

Services that, by default, will have 3 replicas (1 per zone)

• beffe
• ingress-nginx
• kafka zookeeper
• kfuse-profiling-server (requires cloud storage)
• pinot zookeeper
• redis
• ui

Services that always use 1 replica

These components remain single-instance. On zone failure, Kubernetes reschedules the pod to a healthy node in another zone.

• az-service
• config-mgmt-service
• grafana
• hydration-service
• kfuse-auth
• kfuse-cloud-exporter (scraper and exporters)
• kfuse-profiler
• kfuse-saml
• rule-manager
• user-mgmt-service

Additional Notes

• Replication factors will be automatically managed for Kafka and Pinot
• Do not override replicaCount unless given specific guidance to do so
• global.numNodes is used to influence replica scaling.

References

• Set PostgreSQL Credentials