Active active cluster with real-time replication

Evidian SafeKit

Applications in mutual failover with real-time crossed data replication

The SafeKit software provides a simple active active cluster with real-time replication on Windows or Linux. Applications are running on two servers in mutual failover. Each server is backup of the other server. And each application works on its own replicated file directories.

SafeKit active active cluster with real-time replication

If one server fails in an active active cluster, all applications will be active on the same server. After restart of the failed server, applications will return to run on their default primary server.

How the active active cluster with real-time replication works?

How it works?

The SafeKit active active cluster is simply configured by deploying two mirror modules with real-time replication. Each mirror module contains its own configuration of virtual IP address, real-time replicated directories and restart scripts.

Note that:

  • the 2 applications Appli1 and Appli2 must be installed on each server for application failover,
  • this architecture is not reduced to 2 applications: N application modules can be deployed on 2 servers with a maximum of 25 modules,
  • each mirror module will have its own virtual IP address, its own replicated file directories and its own recovery scripts.

Video: active-active cluster with real-time replication >

Example of an active active cluster with real-time replication

The Hyper-V replication automatic failover and load balancing solution is an example of an active-active cluster with N mirror modules replicating N virtual machines between two physical servers. In this configuration, a mirror module replicates a full virtual machine and restarts the virtual machine in case of failure. There is no virtual IP in such a module because restarting a VM on a server makes automatically the IP failover of the VM. And an application is installed in one single VM in this architecture.

As presented in the Hyper-V cluster demonstration, an active active cluster can implement real-time data replication for directories inside the operating system disk. Note that replicating data inside the system disk is possible with byte-level file replication and impossible with block-level disk replication.

Another way to implement an active active cluster with SafeKit is the network load balancing cluster described here.

SafeKit High Availability Differentiators against Competition

SafeKit Modules for Plug&Play High Availability Solutions

Demonstrations of SafeKit High Availability Software

SafeKit Webinar

This webinar presents in 10 minutes Evidian SafeKit.

In this webinar, you will understand:

  • mirror and farm clusters
  • cost savings against hardware clustering solutions
  • best use cases
  • the integration process for a new application

Microsoft SQL Server Cluster

This video shows a mirror module configuration with synchronous real-time replication and failover.

The file replication and the failover are configured for Microsoft SQL Server but it works in the same manner for other databases.

Free trial here

Apache Cluster

This video shows a farm module configuration with load balancing and failover.

The load balancing and the failover are configured for Apache but it works in the same manner for other web services.

Free trial here

Hyper-V Cluster

This video shows a Hyper-V cluster with full replications of virtual machines.

Virtual machines can run on both Hyper-V servers and they are restarted in case of failure.

Free trial here