N-1 Redundancy Clustering: High Availability for Multiple Applications with One Backup
High availability with data replication and application failover from N servers to 1
N-1 redundancy

How the N-1 redundancy works?
SafeKit provides a simple N-1 redundancy cluster with N applications running on N servers and with a single backup for failover. In a SafeKit N-1 redundancy cluster, each application works on its own replicated directories.
In case of failure of one primary server unlike the active-active cluster, the backup server doesn’t have to handle a double workload.
This assumes there is only one failure at a time in the N-1 redundancy cluster. The solution can support multiple primary servers failures at the same time, but in this case the single backup server will have to handle the combined workload of all the failed servers.
How to implement N-1 redundancy?
The SafeKit N-1 redundancy cluster is simply configured by deploying N mirror modules on N+1 servers.
Note that:
- all applications (Appli1, Appli2, Appli3) must be installed on the single backup for application failover,
- each mirror module will have its own virtual IP address, its own replicated file directories and its own recovery scripts.
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| Resource Type | Description | Direct Link |
|---|---|---|
| Key Features | Why Choose SafeKit for Simple and Cost-Effective High Availability? | See Why Choose SafeKit for High Availability |
| Use Cases | Explore How SafeKit Ensures the High Availability of Critical Infrastructure | See All Use Cases (OEM Software, Edge Servers, SCADA, and more) |
| Deployment Model | All-in-One SANless HA: Shared-Nothing Software Clustering | See SafeKit All-in-One SANless HA |
| HA Strategies | SafeKit: Infrastructure (VM) vs. Application-Level High Availability | See SafeKit HA & Redundancy: VM vs. Application Level |
| Technical Specifications | Technical Limitations for SafeKit Clustering | See SafeKit High Availability Limitations |
| Proof of Concept | SafeKit: High Availability Configuration & Failover Demos | See SafeKit Failover Tutorials |
| Architecture | How the SafeKit Mirror Cluster works (Real-Time Replication & Failover) | See SafeKit Mirror Cluster: Real-Time Replication & Failover |
| Architecture | How the SafeKit Farm Cluster works (Network Load Balancing & Failover) | See SafeKit Farm Cluster: Network Load Balancing & Failover |
| Competitive Advantages | Comparison: SafeKit vs. Traditional High Availability (HA) Clusters | See SafeKit vs. Traditional HA Cluster Comparison |
| Technical Resources | SafeKit High Availability: Documentation, Downloads & Trial | See SafeKit HA Free Trial & Technical Documentation |
| Pre-configured Solutions | SafeKit Application Module Library: Ready-to-Use HA Solutions | See SafeKit High Availability Application Modules |