Mission-critical computing, also known as a mission-critical system, is any IT component (software, hardware, database, process, application, etc.) that performs a function essential to business operations. Failure or disruption of a mission-critical factor adversely affects the mission or activity which it supports, and may affect the survival of the business as a whole. For example, online banking systems, traffic control systems and communication systems are mission-critical computing systems that result in business loss if they fail.
Mission-critical computing may also be used as an umbrella term for any IT system or network device whose loss would cause business operations to fail. System resilience, high availability, redundancy, backup and other IT strategies can protect business operations and maintain uptime if a mission-critical component fails. For large enterprises, database systems and process control servers are considered mission-critical computing. Data centers and database servers for Internet applications must be protected from potential failures caused by software corruption, power shortages, faulty hardware and environmental disasters. Replicating data across multiple server clusters is another way to protect mission-critical computing workloads, prevent application downtime and assure data availability. A server cluster is a group of linked servers that work together to improve system performance, load balancing and service availability. If a server fails, other servers in the cluster can take over the functions and workloads of the failed server.
To extend high availability for mission-critical computing, physical and virtual servers can be clustered together. Geo clustering helps minimize the effects of regional disasters, providing service failover across any distance. On Linux-based systems, live kernel patching can reduce downtime by allowing on-the-fly fixes without rebooting. SUSE Linux Enterprise High Availability Extension virtually eliminates unplanned downtime with features that protect mission-critical computing. SUSE Linux Enterprise Server for SAP Applications includes an integrated clustering solution for physical and virtual Linux systems to protect mission-critical SAP HANA databases.