Let’s get started: What is cloud computing?

What exactly is the cloud? What are the advantages and disadvantages of the cloud and how does the cloud differ from virtualization?

Martin Gavanda

My friends often ask me what a cloud architect actually does and what is the cloud? Let me get this straight. Welcome to the Cloud Encyclopedia!

Cloud computing is a way to access various infrastructure services on-demand, i.e. whenever they are needed. Whether it’s traditional computing power, database systems, networking or other software, all with a software-defined infrastructure. So no waiting for cables to be plugged in.

The cloud brings a number of advantages over traditional on-premise virtualization, but these go hand in hand with a conceptual shift in thinking about infrastructure and also bring a number of security challenges.

Cloud computing: key benefits

Operational costs instead of investment costs: no direct investment in hardware or data centre is required when using cloud services. All service charges are clearly predictable and the customer only ever pays for the power or service consumed.
Speed of service set-up: compared to traditional on-premise infrastructure, it is possible to draw computing or other resources at any time and immediately. You don’t have to wait more than a few minutes for the service to be completed (for most services).
Unlimited service scaling: most cloud providers have a massive infrastructure within which it is easy to run almost any type of service or application.
Cost flexibility: because in most cases the payment corresponds to the actual power consumed, the cloud is ideal for applications that have varying infrastructure requirements over time or for temporary projects.
Available technologies: providers offer a number of very advanced services for efficient computing that are easy to implement and can be tested at very low cost, which would be technically and time consuming outside of cloud services.
Global reach: Cloud providers typically have a large number of data centres located in different parts of the world (or continent).

Cloud computing: disadvantages and concerns

Security & compliance: in most cases, data is not stored on-site, but in one of the provider’s data centres. It is therefore necessary to consistently consider different approaches to data security. It can also be crucial whether the cloud provider has specific certifications and is continuously audited.
Higher costs: A direct comparison of running a system on owned, leased hardware or hosting leads to the misleading assumption that large cloud providers offer very expensive services. In fact, when factoring in the actual cost of providing corporate internal and B2B/B2C applications (to maintain sufficient availability and performance), these costs are at least equal with significantly higher security and technical and cost flexibility.
Too many services: Most of the world’s cloud providers offer a multitude of services that can make it difficult to navigate and choose a specific solution.
Service changes: Cloud services are constantly evolving for the benefit of the customer and it is necessary to regularly evaluate and apply current offerings. By gradually changing the service, the provider may force the subscriber to change the application environment, reconfigure the architecture, etc. Fortunately, these changes are always managed and communicated well in advance.
Technology and lack of training: typically, several new roles need to be created within an organisation to be responsible for the correct running of applications and services in a cloud environment. At the same time, it is necessary to take into account the costs of employee training and knowledge transfer between teams.
Access control: In traditional IT, each team has “keys” to its technology. When you are first introduced to cloud technologies, you need to take a similar approach to resource groups and consider well the necessary ownership and management roles. There are a specific number and types of roles for each service.
Cost control: As it is very easy to set up any service almost immediately, it is advisable to closely monitor and audit the entire lifecycle of the services in operation.
Data connectivity: internet connectivity is becoming absolutely crucial for consuming cloud services. Its failure can have a fatal effect on the operation of the organisation. The second crucial aspect is the charging of certain types of data transfers.

Cloud vs. virtualization

Among the common myths is the comparison between cloud environments and virtualization (typically on-premise). Cloud computing obviously builds on the foundations laid by virtualization, but it brings a number of other key features and functions that are difficult to implement on your own hardware.

Automation

If manual intervention by the infrastructure team is needed to set up the service, it is not cloud computing, but variously advanced virtualization.

Example: A customer (whether internal or external) requires a new service to run a web application.

Cloud: The infrastructure is automatically set up according to a specific specification.
Virtualizace: The infrastructure team takes the documents and within a few hours or days prepares the service and sends the required deliverables.

Self-Service

Cloud computing is characterised by a self-service approach to setting up and running a service.

Example: A customer requests to set up a new service.

Cloud: The customer logs in to the self-service portal, where he chooses the service he wants to run from an assigned catalogue.
VirtualizaceA: The customer contacts the deployment team with a request to set up a service and the service is then handed over for use.

Pay-as-you-Go

Cloud computing is based on transparent charging for services. If we are not able to measure (ideally in real time) the power consumed and charge for it, again it is not cloud computing.

Example:A customer has set up a new service.

Cloud:The service (or the component that makes up the service) has a clearly specified price that is billed to the customer (generated invoice, automatic billing, in-house accounting, etc.).
Virtualizace: The development department required a new set of test servers to be set up, however there is no billing for consumption of this service (typically within in-house accounting).

Scaling services

If an investment in new hardware is required to create or modify a service, it is not cloud computing. Within its framework, it is possible to implement a compatible extension of an upscale or outscale service immediately and mostly without failure.

Example: With a daily load of a large number of users, the customer’s application slows down.

Cloud: Cloud administrator will change the performance and amount of application nodes on the fly and increase the performance on the database. They can immediately see the impact this change will have on their monthly bill.
Virtualization: The application administrator communicates with the virtualization administrator to determine if the virtual resources of existing virtual servers can be increased, if there is spare capacity reserved on the host servers, and to request the creation of new nodes for the application layer. If he is lucky, the capacity is provided to him within the framework of change management. If not, it addresses the purchase of additional capacity and waits for delivery and installation of new systems within weeks.

If it’s a bit clearer to you, I’ll sort out the different types of cloud next time, because public isn’t actually very public and you’ll come across private cloud as often as a bunch of saffron.

This is a machine translation. Please excuse any possible errors.