Cloud Delivery and Hosting Models - Deploying and Managing a Cloud Infrastructure - page 170

Cloud Consumers These are not really the end users as you might thing. They are also
known as resellers; they buy services from cloud service providers through service models
such as IaaS and SaaS and then push them to the end user in different flavors. The best
example of this would be website owners that lease computing resources from cloud service
providers in order to create virtual web servers that in turn serve the end users who visit the
website. Well-known companies like Pinterest, Instagram, and Netflix rely on cloud service
providers to keep their services running, in particular AWS.
End Users As the name suggests, end users are at the end point of the business hierarchy,
the consumers. They can be individuals or other businesses or organizations who make use
of the system and are not part of its distribution or upkeep. They make use of their own
equipment and IP networks providers.
These are the key players, and each has its own responsibilities and accountability
toward the system, which varies depending on the situation.
Responsibility for Service Impairments
Outages can be the result of vulnerabilities or imperfections in the software and applications,
the hardware, the cloud environment itself, the network, and data. They can even be due to
operational and service policies as well as natural disasters and human error. In the telecom-
munications sector, three traditional categories have been identified for outage accountability:
Product-Attributable Outages These are outages that result from hardware or software
faults such as malfunctioning hardware and software bugs.
Customer- or Provider-Attributable Outages Includes downtime caused by scheduled
maintenance and human errors. In the case of customers, their equipment or network
could be the cause of an outage.
Externally Attributable Outages These outages are out of the control of operators and
humans. Natural disasters and malicious acts fall into this category.
Accountability for problems with cloud servers is more complex, so these categories don't
really apply. For example, accountability is usually now split between the cloud consumer and
the service provider because the two of them are working together to deliver cloud services
to end users. The service providers usually provide the virtual and hardware infrastructure
while the cloud consumers make use of this infrastructure to run their applications, which
end users ultimately use. We can break down accountability on a per-element basis, accord-
ing to a portion of cloud services.
Accountability Categories
Cloud computing is all about interaction between many different layers of application, plat-
form, infrastructure, and network. Different layers might be offered by different providers.
Because multiple entities can be involved, the effects of problems with each layer may go
well beyond the normal business domain of a provider. Thus, it can be difficult to determine