Software Defined Data Center (SDDC)

Cloud Computing is becoming more and more important for companies. Having your own hardware resources on site are a thing of the past, as are the as­so­ci­ated costs, par­tic­u­larly high ac­quis­i­tion costs – the option of obtaining the required computing and storage ca­pa­cit­ies from a provider is very at­tract­ive.

Thanks to vir­tu­al­ised computing and storage power, as well as software defined networking, it is now even possible to rent complete data centre struc­tures: Providers no longer only provide storage and server per­form­ance, but also network com­pon­ents such as switches, load balancers or firewalls as virtual resources that can be con­veni­ently con­trolled using software. It is therefore hardly sur­pris­ing that not only providers but also an in­creas­ing number of experts see these Software Defined Data Centres (SDDCs) as the data centre model of the future. The following sections explain why this is the case and how a software-con­trolled network works at all.

The software-defined vir­tu­al­isa­tion and provision of computing power (software defined computing) and storage space (software defined storage) have long es­tab­lished them­selves within the portfolio of cloud providers. For some time now, the future-oriented IaaS model, in which a higher-level software acts as a central control unit, has also been used for ad­min­is­trat­ing network struc­tures (software defined net­work­ing).

A software defined data centre (SDDC) combines these three ap­plic­a­tion-driven in­fra­struc­ture services so that users can build their own cus­tom­ised data centre. Using the ap­pro­pri­ate software, typical com­pon­ents like routers, switches, servers load balancers or firewalls can be in­di­vidu­ally booked and organised in the virtual network without having to purchase their own hardware. Instead, it is provided by the IaaS provider, and they are also re­spons­ible for the main­ten­ance and security of the devices. If certain com­pon­ents are no longer needed, they can be removed from the SDDC at any time. You can also add ad­di­tion­al hardware to a software defined data centre if larger struc­tures are required.

Just like any software-defined IT resource, the sep­ar­a­tion of control and data levels plays an important role in SDDCs: All control functions are ab­strac­ted in advance from the in­teg­rated hardware and im­ple­men­ted in higher-level software, which then functions as the control centre (or “Control Plane”) of the virtual data centre. It takes over all tasks that go beyond simple data pro­cessing at the data level (“Data Plane”) – for example, de­term­in­ing where an ap­plic­a­tion or a certain process is executed, which path a data package should take, or exactly where files should be stored.

Com­mu­nic­a­tion with the various devices works through stand­ard­ised protocols like OpenFlow, BGP (Border Gateway Protocol) or NETCONF. These enable the control plane to uniformly control and expand the functions of the hardware com­pon­ents, re­gard­less of which man­u­fac­turer they come from. In addition, it is not necessary to implement changes on each in­di­vidu­al device, since the cor­res­pond­ing in­form­a­tion can also be passed on centrally – with just a few clicks, or even auto­mat­ic­ally, through the software defined data centre’s control software.

Software defined data centres make full use of vir­tu­al­isa­tion tech­no­logy, making ad­min­is­tra­tion a mammoth task. The virtual com­pon­ents and the un­der­ly­ing hardware must be formed into a unit that is still easy to oversee and manage. In par­tic­u­lar, the fluid bound­ar­ies between real and virtual data centres present operators with major chal­lenges: For example, it is necessary to perfectly harmonise the mediating tools between the virtual and physical en­vir­on­ment. Otherwise, an error may be reported for a virtual component even though it ori­gin­ates at the physical level.

The com­bin­a­tion of the various software defined services (computing, storage, net­work­ing) is also more difficult than it might appear: The in­di­vidu­al software-defined IaaS options are of varying maturity and have also es­tab­lished various protocols and in­ter­faces, which must also be combined in the SDDC. This is also reflected in the hardware, which on the one hand must be easy to vir­tu­al­ise and on the other hand should support the in­ter­ac­tion of various virtual server, storage and network com­pon­ents beyond its own hardware limits. This is the only way in which the software defined data centre can guarantee the multi-client capable use of the in­fra­struc­ture.

The goal of software-defined services is maximum flex­ib­il­ity, auto­ma­tion and ef­fi­ciency. To achieve this goal, hardware de­pend­ency must be overcome and a maximum degree of vir­tu­al­isa­tion must be achieved. The result is IT in­fra­struc­tures without the physical lim­it­a­tions of tra­di­tion­al en­vir­on­ments, which can be flexibly adapted to user re­quire­ments and scaled ac­cord­ingly. After vir­tu­al­ised mass storage, server and network solutions, this approach is now being extended to a complete virtual data centre in the form of the software defined data centre, which has various ad­vant­ages over the tra­di­tion­al data centre with dedicated hardware:

• Sim­pli­fied hardware man­age­ment: SDDCs replace isolated hardware tech­no­lo­gies and enable cent­ral­ised man­age­ment of all embedded com­pon­ents. This makes it easier for providers to build and deploy resources and for customers to control and monitor them. Companies also benefit from the fact that the purchase of their own hardware is com­pletely elim­in­ated.
• Lower costs: Software defined data centres are more cost effective than tra­di­tion­al data centres for two reasons. On the one hand, a large part of the hardware is cheaper due to the lack of control logic; on the other hand, simple scalab­il­ity helps customers keep costs as low as possible.
• High planning re­li­ab­il­ity: By setting up or using a software-defined data centre, you are well equipped for future tech­no­lo­gic­al de­vel­op­ments. New functions can be in­teg­rated much more easily than in a tra­di­tion­al data centre. The good scalab­il­ity also allows selected resources to be increased or reduced at any time.
• High re­li­ab­il­ity: SDDC solutions are very fail-safe because the software-based ar­chi­tec­ture easily com­pensates for hardware failure. For this purpose, the cor­res­pond­ing workloads are trans­ferred to other com­pon­ents within a very short time, without manual access to the failed devices being necessary.
• Increased security: In contrast to the tra­di­tion­al in­fra­struc­ture of data centres, the SDDC model enables all security-relevant in­form­a­tion to be bound to the virtual machines them­selves. Security de­fi­cien­cies, e.g. due to in­ad­equate con­fig­ur­a­tions, can therefore prac­tic­ally be ruled out.
• Less know-how required: Stand­ard­isa­tion, open protocols and man­u­fac­turer-in­de­pend­ent pro­gram­ming means not just more flex­ib­il­ity, but also less de­pend­ence on spe­cial­ist knowledge. The use of a software defined data centre therefore makes it a large number of ad­di­tion­al training courses and trained spe­cial­ist personnel un­ne­ces­sary.

Software-defined services like a software defined data centre are becoming in­creas­ingly important due to their great ad­vant­ages over tra­di­tion­al in­fra­struc­ture models. However, renting a complete data centre is only a pos­sib­il­ity for few companies. For this reason, IaaS providers’ SDDC offerings have so far mainly been aimed at en­ter­prise customers who either want to sup­ple­ment their own struc­tures with virtual data centre struc­tures (hybrid solution) or want to replace them step by step. In the long term, the use of software-con­trolled storage, computing power and network com­pon­ents pays off in par­tic­u­lar if the following scenarios are targeted:

• Op­tim­isa­tion of your own data centre: Those who already have their own data centre take the next logical step with an SDDC – es­pe­cially if software defined storage and software defined servers already play a role in the current struc­tures.
• Dynamic con­nec­tions: A software defined data centre is perfect for es­tab­lish­ing dynamic con­nec­tions with in­di­vidu­al bandwidth al­loc­a­tion and guar­an­teed Quality of Service (QoS) between different locations. In this way, different company locations (internal or partner) or used data centers can be connected ef­fi­ciently.
• Optimal network access control: SDDC provides a cent­ral­ised and con­veni­ent way to define per­mis­sions for all users and devices accessing an in­teg­rated network, including access control re­stric­tions, service chain in­teg­ra­tion and ap­pro­pri­ate quality of service.
• Auto­ma­tion of IT processes: Virtual data centres greatly simplify the work of ad­min­is­trat­ors – es­pe­cially through the high degree of auto­ma­tion of processes that are usually done manually. The software-defined approach is therefore a decisive factor in relieving the burden on existing IT personnel.
• Con­sol­id­a­tion of classic cloud services: Tra­di­tion­al cloud services basically follow the same approach as software-based services by focusing on vir­tu­al­isa­tion and policies. However, merging the services of different providers is often a major challenge that can be mastered with a software defined data centre.

Software Defined Data Centres combine all relevant IaaS offerings like storage, computing power and networks in virtual struc­tures that replace a tra­di­tion­al data centre one-to-one and can be con­trolled via a central software solution. Typical problems like com­plic­a­tions when merging or expanding the functions of devices from different man­u­fac­tur­ers or when in­creas­ing or de­creas­ing resources are a thing of the past in a fully virtual data centre. If the relevant hardware is even better equipped for use in the SDDC, en­ter­prise companies will probably not be able to avoid this flexible and highly scalable tech­no­logy in the future.