Redis backend options for active-active Harbor deployment using Helm chart

[srbhklkrn]

Hi Harbor team,

We're in the process of deploying Harbor in an active-active setup across two data centers, using the official Helm chart. Our goal is to run two Harbor frontends sharing a common backend that includes:

• An external PostgreSQL database with high availability
• ECS S3 for image/chart storage
• And a shared HA Redis backend

We’ve hit a blocker around the Redis setup.

From the Helm chart defaults Harbor components are configured to use multiple Redis databases (e.g. DB 0 for core, DB 1 for jobservice, DB 2 for registry, DB 5 for trivy). However, we’re evaluating two options:

• Open-source Redis: Supports multiple DBs but lacks built-in high availability (HA)
• Enterprise Redis (HA): Supports HA but only provides a single DB index (usually DB 0)

Questions:

1. Can Harbor components safely share a single Redis DB in this type of deployment, or does it require multiple isolated DB indexes for correct behavior?
2. What are the risks or limitations of running all components on the same Redis DB (e.g., key collisions, performance bottlenecks)?
3. Are there any known or recommended strategies for deploying Harbor with HA Redis backends that only support a single DB?
4. Is Redis Sentinel or Redis Cluster support officially planned or supported in the Harbor Helm chart?

We intend to share the same backend between both Harbor frontends to ensure consistency, reliability, and full visibility across deployments.

Thanks in advance for your guidance!