Availability of IT resources in the outsourcing model (part II)
When using hosting services, we should be aware that we are not the only ones. Most often, users do not disturb each other, but from time to time the so-called black sheep may appear. Therefore, it is necessary to understand the ways in which individual services are provided to avoid later disappointment.
In the first article of this series we presented the division into types of hosting services and their basic characteristics. Now, we will focus on one specific feature – their availability. This is easiest to explain using examples from the housing market.
Shared server
This is a device that all users use equally. Its performance and management flexibility are not guaranteed. It’s like renting a room in an apartment or dormitory. We do have our own bed, but no privacy. Roommates are active all the time, so you have to wait a bit for the opportunity to use the kitchen or bathroom. Some suspicious guests are always hanging around.
But this is not the only inconvenience. The tenant has no influence on the room decor, furniture or security. All administrative matters must be reported to the owner of the apartment or the building administration.
Similarly with shared servers. Their resources are used by many customers, but all administrative tasks are the responsibility of the service provider. The user does not have a guarantee of high availability of such solution, especially when other customers (as well as co-tenants in the above example) cause confusion.
Virtual private server (VPS)
Thanks to virtualization, VPS users may feel that they have the entire server to themselves (in fact, however, they still share the physical device with others). The user gains control over the operating system and application settings. A similar situation is renting a flat in a tenement house. The level of privacy increases significantly compared to renting a room, but not all inconveniences are eliminated. Weekend peace is disturbed by the renovation carried out by the neighbors or the birthday celebrated loudly, there are also breakdowns of the intercom or elevator, and a leaky drainage pipe the floor above causes streaks on the ceiling.
When renting an apartment, you can decide to a certain extent about its decor or furniture, but most problems should be solved in cooperation with the owner or the building administration. The same is true for virtual private servers – any problem not directly related to the server’s internal environment should be solved jointly with the service administrator.
Dedicated server
Having a server for exclusive use in a professional server room is like renting a single-family house. The entire building is at the customer’s disposal and no one disturbs the peace, there are no children playing instruments at odd times and it is only the tenant who decides when to invite guests or organize events.
The tenant is also responsible for administering the building, arranging for its maintenance and some formal issues. In selected areas, however, responsibility is shared because administrative (municipal, district or housing) authorities are responsible for them.
Nevertheless, the tenant still uses the services provided by public utility institutions: power plant, waterworks or municipal services company responsible for garbage collection. Similarly, the data center provides the company that uses dedicated servers with space lease, supply of electricity and air conditioning with guaranteed parameters and physical protection of the data center building.
Cloud computing
Flexibility guaranteed by cloud services – present in both management and accounting issues – can be analogous to the services provided by hotels. Guests use only the functions they need. They can rent a room, a conference or banquet room, go to the restaurant, gym or swimming pool. Some options are free, others will be added to the invoice. At any time, further services can be added or those no longer needed can be ended.
In a large and well-managed hotel, just like in a reliable data center and cloud services operator, there should always be enough space. Customers decide what their requirements are, and the administration of the facility ensures that all their wishes are fulfilled to their fullest satisfaction.
In the last, third article of this series, presenting the criteria for selecting hosted services provided by data centers, we analyze how their various models guarantee the security of processed data.