Redis Cluster

Redis Cluster on vDB is a Redis deployment with a Non-sharding architecture consisting of 1 Master node and up to 9 Replica nodes (2–10 nodes total), with automatic failover and vBackup integration for comprehensive data protection.

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Architecture

Redis Cluster on vDB follows a 1 Master – N Replicas model:

• Master node: Handles all read and write operations.

• Replica nodes (1–9): Asynchronously replicate data from the Master, serve read operations, and are ready for failover.

• Automatic Failover: When the Master fails, a Replica is automatically promoted to become the new Master. The cluster continues to operate after failover completes.

┌─────────────┐
│   Master    │  ← Read / Write
└──────┬──────┘
       │ Async Replication
  ┌────┴────┐
  ▼         ▼
Replica 1  Replica 2 ...  ← Read / Failover

Scope: Redis Cluster on vDB currently supports Non-sharding mode (single shard only). Multi-shard sharding will be developed in a future release.

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Single-node vs Cluster Comparison

Feature	Single-node	Cluster (Non-sharding)
Masters	1	1
Max Replicas	5	9
Automatic Failover	No	Yes
Read Scaling	Yes (via replicas)	Yes (via replicas)
Write Scaling	No (single writer)	No (single writer)
Backup Integration	No	Yes (vBackup — Policy + Location)
Best for	Dev, staging, small workloads	Production, High Availability

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Scaling Replicas

You can change the number of Replicas in a Cluster after creation with no downtime. The system performs scaling step by step:

• Scale up: Adds one replica at a time, waiting for each replica to complete its initial sync before adding the next.

• Scale down: Removes replicas in descending index order, waiting for each step to complete before proceeding.

Each change can only increase or decrease by 1 node at a time. The UI shows only two options (current−1 or current+1) — jumping multiple steps in a single action is not allowed. This ensures each sync completes before the next step, preventing replication errors during abrupt scaling.

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Backup Integration (vBackup)

Redis Cluster has built-in integration with vBackup to protect your data:

• Auto Backup: Runs on the schedule defined by the Backup Policy selected during cluster creation.

• Manual Backup: Create a Full Snapshot on demand at any time from the cluster detail page.

• Restore: Create a new cluster from an existing restore point in Backup Center.

Detail	Value
Backup type	Full Snapshot (Incremental not supported)
Storage	vStorage (S3-compatible) with Object Lock
Concurrency limit	1 backup job at a time
When quota exceeded	Returns QuotaExceeded error, no auto-retry

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Next Steps

I want to...	Go to...
Create a new Redis Cluster	Create a Redis Cluster
Manage topology, backups, delete cluster	Manage a Redis Cluster
View limitations and constraints	Limitations