As businesses become more and more dependent on access to their digital assets, there is a growing intolerance to outages and down times. Continuous availability and high availability anywhere, anytime with any kind of device is the mantra of the age. Businesses struggling to meet this demand turn to cloud services to fulfil these expectations. Cloud service providers too, in keeping with their promise, are making an all out effort to bring the right technologies to the table so that their customers are never offline and their data never becomes inaccessible, whatever the circumstances.
Continuous availability of information requires planning. Once the customer has identified the applications that are mission-critical and must be continuously available, cloud service providers will recommend continuous backup of these applications. The backup process is orchestrated quietly in the background with no disruption to the production systems. Technologies such as bandwidth throttling, are used to ensure that the backup process consumes only redundant bandwidth or a minimal bandwidth. Data transmitted to the remote server is then continuously replicated on to one or more geographically dispersed servers to create redundant stores of the same information for future recovery.
The cloud service provider is very disaster conscious and has the responsibility of ensuring that disasters that impact the cloud data centre do not get passed on to individual customers using the services in the cloud. As part of the disaster recovery plan for the data centre, the cloud service provider links together the primary and secondary servers (that are geographically dispersed) in failover configurations. Secondary servers kick start their activity the moment the primary server develops a glitch or fails in any manner. Customers accessing or updating information are seamlessly shifted over from the primary server to the secondary server. The operations are so smooth that customers may not even realise that they have switched servers during a production operation. In the process, the cloud service provider creates a time-pocket in which the primary server can be set right and brought back into operation. High availability is an automatic outcome of this operation.
Customers who have geographically dispersed activities can also take advantage of cloud services multi-site data storage functions. If the enterprise has branches in the local area where a replication server is housed, the enterprise can configure the local replication server to service the requests of the branch. This will cut down on any latency that may be experienced by the branch in accessing and working with data stored on the centralised remote primary server. Any updates or operations on the enterprise data can be reverse-replicated from the secondary server to the primary server continuously.
It is no wonder that high availability is the guarantee of cloud service providers.