What to choose: on-premise, private, public, hybrid, or multi-cloud?

There are several solutions for storing IT resources in a company: in-house data centre, private cloud, public cloud… It is also possible to use more than one environment simultaneously, thus managing a hybrid cloud or a multi-cloud solution.

The article outlines what each type of infrastructure brings about and its benefits and drawbacks. There is no clear-cut rule for whom a particular environment will work – the choice depends on several factors, including the necessity to meet regulations, the level of security, or the need for scalability.

On-premise solution – what is it, advantages and disadvantages

On-premise, sometimes shortened to “on-prem”, is a local data centre operated by an in-house IT department or an outsourcing company. It involves the lease or purchase of machines and (most often) the construction and maintenance of the whole infrastructure – hardware, software, networks and a server room that provides suitable conditions. Scalability, in the case of an on-premise solution, is linked to the purchase and configuration of additional devices and sometimes the expansion of the IT team.

In the case of an on-premise solution, infrastructure management also includes maintenance and care of the hardware itself, not just the software layer. By having your own data centre, you have influence over the type of machines, making it easier to comply with legal requirements, such as the GDPR or the guidelines of the Financial Conduct Authority.

Owning your own devices comes with a fixed, predictable cost. The company incurs one-off expenses for the construction or extension of a server room, the provision of appropriate conditions (space, air conditioning, power generators) or the purchase of additional servers. The Total Cost of Ownership is rather flat and includes, i.a., buying new machines, the salaries of the system administrators, the electricity or the internet connection.

Benefits of the on-premise model

• Low cost: in the case of leased or co-located servers, the cost of an on-premise solution can be relatively low.
• Great control: you can control resources and create dedicated services with an on-premise solution.
• Easier compliance with regulations: on-premise infrastructure and hardware management makes it easier to comply with legal requirements such as data storage or processing.

Drawbacks of the on-premise solution

• The difficulty of scaling: in the on-premise model, scaling is done by buying more machines, which can entail additional costs (like an extension of the server room or hiring more IT specialists).
• The need for a server room: preparing a dedicated space and maintaining the right conditions can be a hassle and, therefore, expensive;
• In-house upkeep: the company owns the servers, so the IT team has to spend time maintaining the physical machines, sometimes at the expense of development work.

Private cloud – definition, pros and cons of the solution

A private cloud combines the provision of server space and infrastructure services to a company on an exclusive basis. Maintenance of the data centre can be outsourced or done in-house. The company uses an internal network and dedicated infrastructure space – thus, not sharing it with others translates into security but also a high cost of upkeeping. The supplier takes care of hardware, maintenance, OS updates, resiliency or scaling. Suppose increased traffic is anticipated to ensure scalability. In that case, the company does not have to incur the cost of buying more servers – it simply increases the leased server space with the supplier. If the company expects spikes in traffic, it only needs to rent more server space from the provider; that makes the cost of scaling lower than with on-premise infrastructure.

In private cloud computing, costs are fixed, even if the load varies. The company pays for server space, IT services and network maintenance. The prices are relatively high because the company rents the entire environment exclusively. This combines with the ability to tailor the infrastructure, machines and services to the needs of the business. The provider can prepare dedicated solutions or purchase devices that meet legal regulations (e.g., processing personal data or online payments).

Pros of a private cloud model

• Out-of-house hardware maintenance: the service provider takes care of the proper conditions of servers, so the internal IT department can focus more on development work instead of upkeeping.
• Scalability: if needed, the provider takes care of increasing or decreasing the resource level. The company does not have to incur the costs of purchasing and maintaining its servers.
• Security and reliability: the environment is isolated even on a physical level, and any external user can’t enter it or consume the resources.
• Control over resources and services: you can develop dedicated infrastructure solutions with a private cloud. 
• The convenience of meeting regulations: the company has a say in the type of hardware and software in the private cloud, so it can easily tailor specifications to meet legal requirements.

Cons of a private cloud model

• High cost: a company incurs the fixed cost of renting an isolated server environment, even if the consumption does not reach its maximum level. 
• Complex environment: maintaining a private cloud requires skill and time, which also implies a higher cost of operating the infrastructure.

Public computing cloud – explanation, benefits and drawbacks

In the case of a public cloud, hardware belongs to external service providers (such as Google, Amazon or Microsoft). The most popular clouds are Google Cloud Platform, Microsoft Azure, and Amazon Web Services.

Public cloud service providers have data centres, extensive server infrastructure and network connections. The physical specification of the hardware is up to the providers, but more and more of them are giving the option of dedicated hardware, such as through the Bare Metal Solution. Maintenance work – hardware operating, maintenance, updates – is carried out by the cloud service provider. 

Resources are made available over the internet via a public cloud platform. In addition to the server space itself, public cloud providers also offer infrastructure services. In the case of GCP, there are around 200 tools and services, including solutions for industries, applications to support rapid deployment and launch of applications, Big Data analytics, and machine learning or artificial intelligence capabilities, to name a few.

Public cloud solutions can be used by any company, adjusting the scope of the service and the level of use to its own needs. In the case of the public cloud, costs are flexible – charged according to consumption, usually on a per-minute or per-second basis.

The public cloud is a fully scalable solution. Scaling can take place automatically (after configuration) or manually by changing the instance’s parameters or running more virtual machines. Public cloud providers ensure high availability of services and stability of the solution – with their extensive infrastructure, they can handle network failures more efficiently than on-premise or private cloud solutions.

Benefits of public cloud

• Scalability: scaling can be manual or automatic, both up- and downscaling. The instance configuration changes in seconds without prior resource provisioning.
• Flexible costs: billing is per second or minute in response to actual consumption.
• Easy access to cloud services: public clouds allow you to build your infrastructure using out-of-the-box building blocks.
• High availability and reliability: thanks to the extensive infrastructure and connections between data centres, the service provider can prevent or minimise failure consequences.

Public cloud drawbacks

• Limited control: the user cannot create new cloud services or modify existing ones; they also have limited options for choosing the physical hardware specification.
• Possible high cost: in the long term, public cloud computing may be more costly than an on-premise solution, especially for applications with constant traffic.
• Dependence on the provider: the user has no influence on the solutions proposed by the cloud provider. If he relies only on one cloud solution, the outage can bring him a lot of losses.

Hybrid cloud – definition, advantages and disadvantages

The hybrid cloud combines a public cloud and an exclusive solution (private cloud or on-premise). It allows taking advantage of both solutions, e.g., the ability to configure and customise services with high computing power in the public cloud. With a hybrid cloud, you can, for example, process sensitive data in your own data centre while scaling traffic spikes to the public cloud.

Advantages of hybrid cloud

• Combining the strengths of both solutions: the hybrid cloud allows you to benefit from the security of your own infrastructure and the ability to create dedicated solutions while providing all the advantages of the public cloud.
• Meeting law regulations: by using the hybrid cloud, you have influence over the devices you own, so you can choose machines that meet legal requirements.
• Scalability: seasonal or sudden increases in traffic can be scaled to the public cloud.
• Fixed cost and charge in the pay-as-you-use model: the charge for a private cloud or on-premise solution is a fixed monthly cost, while in the case of a public cloud, the cost is flexible, and dependent on consumption level.

Disadvantages of hybrid cloud

• Possible data transfer troubles: as the cloud operates over the internet, there may be an issue while transferring resources between environments if the connection is of poor quality. A fast and stable internet connection is necessary to ensure smooth data transfer.

Multi-cloud – what’s that, pros and cons

A multi-cloud solution involves the simultaneous use of services of two or more cloud providers. The distribution of resources between environments depends on the company’s needs – for example, the main infrastructure may be built on Google Cloud Platform but extended with AWS services. 

Using multi-clouds allows you to be independent of a single provider. Although technology giants look after public clouds and ensure high availability, failures happen to them too (as with on-premise solutions or private clouds – a problem can happen anywhere; the important thing is how to react and minimise the impact). With multi-cloud, even if one provider struggles, the distributed system will, at least partially, continue to operate.

Pros of multi-cloud

• No reliance on a single provider: using solutions from several public clouds ensures greater system stability and prevents the consequences of potential infrastructure failure.
• Combining services from several environments: in a multi-cloud model, you can expand your infrastructure with cloud services from different providers.

Cons of multi-cloud

• Problematic management of several environments: maintaining a multi-cloud infrastructure can be difficult and costly, but you can take advantage of tools like Terraform to maintain greater control.

Which infrastructural solution to choose?

There’s no simple answer to this question. The choice of infrastructure should be preceded by a stage of analysis of business and technological needs and the direction of the development plans.

FOTC has cloud engineers and security and network specialists on board who can design the infrastructure architecture. If you want to benefit from the expertise of our specialists and create the best possible environment for your business, contact us.

See also:

• Cloud technologies made simple. What is cloud computing and what can you gain from it?
• Multicloud strategy – a way to benefit from many clouds at once?
• Amazon Web Services vs Microsoft Azure vs Google Cloud Platform – which cloud to choose?