A cluster-aware application is a software application

Application software

Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

 designed to call cluster API

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

s in order to determine its running state, in case a manual failover

Failover

In computing, failover is automatic switching to a redundant or standby computer server, system, or network upon the failure or abnormal termination of the previously active application, server, system, or network...

 is triggered between cluster nodes for planned technical maintenance, or an automatic failover is required, if a computing cluster node encounters hardware or software failure, to maintain business continuity

Business continuity

Business continuity is the activity performed by an organization to ensure that critical business functions will be available to customers, suppliers, regulators, and other entities that must have access to those functions. These activities include many daily chores such as project management,...

. A cluster-aware application may be capable of failing over LAN

Local area network

A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...

 or WAN

Wide area network

A wide area network is a telecommunication network that covers a broad area . Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations...

.

Cluster-aware application characteristics

• Use TCP/IP to maintain heartbeat
  Heartbeat
  Heartbeat may refer to:* Cardiac cycle of the heart* Heart sounds* Pulse* The interval for keeping alive a push e-mail connection* Heartbeat , a British police drama* HeartBeat Heartbeat may refer to:* Cardiac cycle of the heart* Heart sounds* Pulse* The interval for keeping alive a push e-mail...
  
   between nodes.
• Capable of transaction processing
  Transaction processing
  In computer science, transaction processing is information processing that is divided into individual, indivisible operations, called transactions. Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state...
  
  .
• Mirroring cluster information in realtime.