The simplest way to view IaaS is as a means of providing access to virtualized computer resources over an Internet connection. IaaS acts as one of three methods of sharing resources over the Internet, alongside SaaS and PaaS. AWS supports IaaS by providing access to virtualized hardware, software, servers, storage, and other infrastructure components. In short, you can use IaaS to replace every physical element in your computing setup except those required to establish and maintain Internet connectivity and those required to provide nonvirtualized services (such as printing). The advantages of IaaS are many, but here are the ones that most people consider essential:
– The host handles tasks such as system maintenance, backup, and resiliency planning.
– A client can gain immediate access to additional resources when needed and then doesn’t need to worry about getting rid of them when the need has ended.
– Detailed administrative tasks are handled by the host, but the client can manage overall administrative tasks, such as deciding how much capacity to use for a particular task.
– Users have access to desktop virtualization, which means that their desktop appears on whatever device they happen to use at a given moment. The use of policy-based services ensures that users must still adhere to company requirements when using computer resources.
– All required updates (software and hardware) occur automatically and without any interaction required by the client.
– Keep in mind that there is no free lunch. AWS and other IaaS providers are interested in making a profit. They do so by investing in huge quantities of hardware, software, and management personnel to oversee it all. The benefits of scale help create profit, and many businesses simply can’t create setups they require for less money.
The definite disadvantages of IaaS
– Billing can become complex because some services are billed at different rates and within different time frames. In addition, billing can include resource usage. The client must ensure that the amount on the bill actually matches real-world usage; paying too much for services that the client didn’t actually use can easily happen.
– Systems management monitoring becomes more difficult. The client loses control over the precise manner in which activities occur.
– A lag often occurs between the time a change in service is needed and the host provides it, so the client can find that even though services are more flexible, they aren’t as responsive.
– Host downtime can affect a large group of people and prove difficult to fix, which means that a particular client may experience downtime at the worst possible time without any means to resolve it.
– Building and testing custom applications can become more difficult. Many experts recommend using in-house equipment for application development needs to ensure that the environment is both protected and responsive.