Quick Answer: What Does High Availability Mean?

What is the purpose of High Availability?

In context of IT operations, the term High Availability refers to a system (a network, a server array or cluster, etc.) that is designed to avoid loss of service by reducing or managing failures and minimizing planned downtime..

What is the difference between fault tolerance and high availability?

The difference between fault tolerance and high availability, is this: A fault tolerant environment has no service interruption but a significantly higher cost, while a highly available environment has a minimal service interruption.

How does high availability work VMware?

vSphere HA provides high availability for virtual machines by pooling the virtual machines and the hosts they reside on into a cluster. Hosts in the cluster are monitored and in the event of a failure, the virtual machines on a failed host are restarted on alternate hosts.

What is considered high availability?

High availability refers to a system or component that is operational without interruption for long periods of time. High availability is measured as a percentage, with a 100% percent system indicating a service that experiences zero downtime. … But four nines uptime is still 52 minutes of downtime per year.

What is high availability in virtualization?

VMware vSphere High Availability High Availability provides uniform, cost-effective failover protection against hardware and operating system outages within your virtualized IT environment. … Restart virtual machines on other vSphere hosts in the cluster without manual intervention when a server outage is detected.

What is high availability software?

High availability software is software used to ensure that systems are running and available most of the time. High availability is a high percentage of time that the system is functioning. … Although the minimum required availability varies by task, systems typically attempt to achieve 99.999% (5-nines) availability.

What is the difference between failover and high availability?

Failover is a means of achieving high availability (HA). Think of HA as a feature and failover as one possible implementation of that feature. Failover is not always the only consideration when achieving HA. … Requiring more nodes to respond means less availability, and requiring fewer nodes means more availability.

What is the most common form of virtualization?

OS Virtualization—aka Virtual Machines Virtualizing an operating system environment is the most common form of virtualization. It involves putting a second instance or multiple instances of an operating system, like Windows, on a single machine.

What does high availability architecture mean?

Definition. In the above definition, high availability is “a design and implementation that ensures a certain degree of operational continuity”, and application architecture refers to the actual concept and design of implementing a new configuration into the particular system.