High availability, as it relates to the cloud is a very convoluted concept. For example, the impetus for my creating this series had to do with the storms in Sydney, Australia, which caused AWS to lose connection to their cloud facility. The thing is that they had no redundant facility anywhere in Australia. Certainly, the costs of standing up another facility in, say, Melbourne, are quite daunting, but the ability to guarantee a greater level of uptime, to me, seems quite worthwhile.
The fault in this case was not necessarily with AWS. In my opinion, the customer base who chose not to research and determine that should an even occur, their applications would be down, as did actually happen. Building for redundancy or uptime is necessary in many cases. Before moving an application to the cloud, be sure all your needs can be satisfied. Those of compliance, cost, and availability are critical. What are your RPO/RTO objectives? How much downtime can your application handle? How much data can you lose? Is there a cost factor associated with a higher degree up both recovery point and recovery time objectives that make these objectives prohibitive? These issues are quite relevant and potentially daunting.
I think that a full Business Industry Analysis is necessary to determine your tolerance to these pain points. However, depending on your industry, there are regulations that must be considered as part of your formula.
OK… back on topic: the scenario in which you’re using a cloud provider, not necessarily only a public provider, but any hosting service, in which your internal environment gets replicated can likely handle a minor outage, but can it remain fully available? If you’re planning on migrating the full ERP system, say the one currently running on Oracle to Oracle Cloud. There are variables that must be evaluated. Oracle has made a huge investment in their infrastructure so as to support all native platform apps into the 12G Cloud release. That being said, be sure that your needs are covered. Even though Oracle’s cloud is suited ideally toward the workloads of Oracle’s databases, you must ensure that there’s ample storage, networking, and redundancy in place to ensure the mission criticality of your business central application.
The messaging is clear, if not entirely overstated. When you choose to make decisions based on cloud architectures and your applications, be sure that you know what your concerns are, your parameters for a successful deployment really are no different than they would be if the workloads were deployed in the on-prem data center.