LifeKeeper can provide High Availability Clustering capabilities to nearly any form of application, allowing you to sell your own software with HA features, or to provide resilience to your existing infrastructure

One of key advantages of SteelEye's LifeKeeper architecture is that target applications do not need to be changed in order to provide application protection.

Instead of requiring any changes to applications, LifeKeeper's Application Recovery Kits (ARK's) are used as an efficient and flexible mechanism to provide recovery of target applications whose reliability and uptime require protection.

ARK's are a set of administration and recovery components that provide LifeKeeper with the ability to manage and control a specific application

Generic ARK

LifeKeeper for Linux core product includes generic application support. In other words, it is possible to write scripts to make custom applications to be supported by LifeKeeper. This is useful for random installations since it typically requires reasonable small amount of work and it is quite simple.

Software Development Kit ("LifeKeeper Extender")

The LifeKeeper Software Development Kit (SDK) provides a user-friendly way to develop integration between LifeKeeper core and any other application, enabling LifeKeeper users to write their own custom recovery kits. Usually a custom recovery kit leverages as many of the existing LifeKeeper resource instances as it can.

The SDK is used when the application recovery is dependent on other resources and a specific behaviour is required to manage the recovery process.

For example, the Apache Web Server Recovery Kit supplies its own webserver/apache resource instance, but its job is merely to start and stop the web server. It creates dependencies of the LifeKeeper supplied comm/ip and gen/filesys resources to protect the IP addresses and file systems it needs to function correctly.

Components of an ARK

Each resource instance consists of two separate components: an action component (for recovery and monitoring) and an administration component (for creation, extension, and removal). The action component performs start, stop, and monitoring operations for the application associated with a resource instance. The administration component is usually attached to a top-level resource instance and performs administration operation, such as creating the entire resource hierarchy, including the associated dependencies. The administration component also includes a GUI interface, which defines how the LifeKeeper Java-based GUI should collect input parameters for the administration components.

Original Source: www.openminds.co.uk