Fault tolerance and availability of systems is an important and relevant topic within every company. A failure due to an error means in most cases an economic damage of a company.
In order to avoid this, businesses use various solutions in order to bridge a system failure or planned downtime. One of these ways is to have a secondary component take over the functions of the affected system components in the event of a downtime. This is referred to as failover solutions or backup mode of an operation. In many companies, "failover" is a supporting component of mission-critical systems.
A common method here is to automatically move tasks to a standby component. The requirement for the method is that it should work as seamlessly as possible for the end user. Automated failover therefore means that normal functions can be maintained despite the inevitable failure due to equipment problems. This requires constant connectivity and mirroring of systems. In addition, regular checks must be made to ensure that this connection is working - the "heartbeat" is usually used for this purpose. If there is no feedback from the heartbeat, the secondary component takes over. However, this can lead to minimal delays when switching to the secondary system. The shorter this delay, the better the failover concept. (Source)
A failover can refer to both the hardware as well as the software components of a system. It involves developing a protection mechanism against failures of the relevant component. Components of IT systems where failovers make sense: Web server/application server, databases, network components and storage components. If we take a web server as an example, a backup server would be a typical failover. In this case, the backup server takes over the tasks of the regular server in the event of a failure.
Here, companies resort to so-called failover clusters in order to ensure high availability for applications and services. But how does a failover cluster work? In a failover cluster, a group of servers work together. This means that as soon as one server fails, another machine steps in. There is no downtime at all. The machine that steps in and then takes over the workloads automatically. (Source)
This means that multiple connection paths, each with the same components, are used in order to ensure that at least one of the paths remains functional and that the system does not fail. A failed path can be caused by the failure of any single component of a path.
With our solution Libelle BusinessShadow® for automated disaster recovery best possible and high availability you can mirror databases, SAP® landscapes and other application systems with a time delay. Your company is therefore protected not only against the consequences of hardware and application errors, but also against the consequences of natural hazards, sabotage or data loss due to human error.
Would you like to learn more about IT terms? In connection with the term failover, high availability and business continuity play an important role. But what exactly do these terms mean? Learn more on our Libelle IT blog and follow us on LinkedIn for regular updates.