VM HA vs Application HA

Evidian SafeKit

Choose between high availability at the application level or at the virtual machine level

High availability at the application level

In this type of solution, only application data are replicated. And only the application is restared in case of failure. Restart scripts must be written to restart the application. This solution is platform agnostic and works with physical machines, virtual machines, in the Cloud.

Application HA

We deliver application modules to implement this type of solution. They are preconfigured for well known applications and databases. You can customize them with your own services, data to replicate, application checkers. And you can combine application modules to build advanced multi-level architectures.

High availability at the virtual machine level

In this type of solution, the full Virtual Machine (VM) is replicated (Application + OS). And the full VM is restarted in case of failure. The advantage is that there is no restart scripts to write per application and no virtual IP address to define. If you do not know how the application works, this is the best solution.

VM HA

We deliver two modules for implementing this solution: one for Hyper-V on Windows and one for KVM on Linux. Several VMs can be replicated and can run on both hypervisors with crossed replication and mutual takeover.

VM HA vs Application HA

VM HA with the SafeKit Hyper-V or KVM module Application HA with SafeKit application modules
SafeKit inside 2 hypervisors

VM HA

SafeKit replication and failover of full VM
SafeKit inside 2 virtual or physical machines

Application HA

SafeKit replication and failover at application level
Replicates more data (App+OS) Replicates only application data
Reboot of VM on hypervisor 2 if hypervisor 1 crashes
Recovery time depending on the OS reboot
Quick recovery time with restart of App on OS2 if crash of server 1
Around 1 mn or less (see RTO/RPO here)
Application checker and software failover
Generic solution for any application / OS Restart scripts to be written in application modules

SafeKit vs Microsoft Hyper-V Cluster & VMware HA

SafeKit with the Hyper-V module or the KVM module Microsoft Hyper-V Cluster & VMware HA
SafeKit with Hyper-V VMware HA 1 Hyper-V cluster
Like  No shared disk - synchronous real-time replication instead with no data loss Dislike  Shared disk and specific extenal bay of disk
Like  Remote sites = no SAN for replication Dislike  Remote sites = replicated bays of disk across a SAN
Like  No specific IT skill to configure the system Dislike  Specific IT skills to configure the system

Note that the Hyper-V/SafeKit and KVM/SafeKit solutions are limited to replication and failover of 25 VMs.

SafeKit: an ideal solution for a partner application

This platform agnostic solution is ideal for a partner with a critical application and who wants to provide a high availability option easy to deploy to many customers.

This clustering solution is also recognized as the simplest to implement by our partners.

SafeKit High Availability Differentiators against Competition

SafeKit Modules for Plug&Play High Availability Solutions

SafeKit Modules for Plug&Play High Availability Solutions

Network load balancing and failover

Windows farm

Linux farm

Generic farm   > Generic farm   >
Microsoft IIS   > -
NGINX   > NGINX   >
Apache   > Apache   >
Amazon AWS farm   > Amazon AWS farm   >
Microsoft Azure farm   > Microsoft Azure farm   >
Google GCP farm   > Google GCP farm   >
Other cloud   > Other cloud   >

Note:

Several modules can be deployed on the same cluster. Thus, advanced clustering architectures can be implemented:

Demonstrations of SafeKit High Availability Software

SafeKit Webinar

This webinar presents in 2 minutes Evidian SafeKit.

In this webinar, you will understand SafeKit mirror and farm clusters.

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