High Availability Architectures Overview
First step - integration via application modules
An application module is a customization of SafeKit for an application. There are two types of modules: the mirror module with real-time data replication and failover and the farm module with load balancing and failover.
In practice, an application module is a “.Safe” file (zip type) including:
1 - the configuration file userconfig.xml which contains:
- names or physical IP addresses of the servers,
- name or virtual IP address of the cluster,
- file directories to replicate in real time (for a mirror module),
- network load balancing criteria (for a farm module),
- configuration of software and hardware failures detectors
2 - the scripts to start and stop the application.
Plug and play deployment
Once an application module is configured and tested with an application, deployment requires no specific IT skills:
1 - install application on 2 standard servers (physical or virtual),
2 - install the SafeKit software on both servers,
3 - install the application module on both servers.
High availability architectures: the different software clusters
SafeKit offers two basic clusters:
- the mirror cluster built by deploying a mirror application module on 2 servers,
- the farm cluster built by deploying a farm application module on 2 servers or more.
Several application modules can be deployed on the same cluster. Thus, advanced clustering architectures can be implemented:
- a farm+mirror cluster with the deployment of one farm module and one mirror module on the same cluster,
- an active/active cluster with the deployment of several mirror modules on 2 servers,
- a Hyper-V cluster with replication and failover of full VMs between 2 active physical servers,
- a N-1 cluster with the deployment of N mirror module on N+1 servers.