System resilience is the ability of a system to withstand a disaster and to recover within an acceptable timeframe. In this section, we will have a detailed discussion on application resiliency and telecommunications resiliency.
Application resiliency – clustering
Clustering helps to protect an application against a disaster. The aim of clustering is to provide for the high availability of the system. A cluster is a software that is installed on every server where the application runs. An application that is clustered is protected against a single point of failure.
Application clusters can be either active-passive or active-active. In an active-passive setup, an application runs only on one node, while other passive nodes are used only if an application fails on the active node.
In an active-active cluster setup, the application runs on every cluster. An active-active setup, though more expensive than an active-passive setup, provides quick application recovery...
