«Data Center Design Criteria Course Content Module 1 Data Center Layers Data Center Feasibility Studies and Project Cost Budgeting Risk Assessment ...»
www.PDHcenter.com PDH Course E173 www.PDHonline.org
Data Center Design Criteria
Data Center Layers
Data Center Feasibility Studies and Project Cost Budgeting
Power and Cooling Systems Analysis
Business Continuity and Disaster Recovery
Data Center Site Selection
Type of Server Farms in Data Center
Server Farm Topologies and Network Infrastructure in Data Center
Electrical Power & Cooling requirement UPS and Battery systems Generator and Automatic transfer switch equipment Fire Alarm System and Sprinkler systems Security Page 1 of 29 www.PDHcenter.com PDH Course E173 www.PDHonline.org Module 1 Data Center Layers The data center design process starts by working with the management staff to determine business’s data center project needs and combine this with the understanding of the trends and migration strategies required in adapting to future changes. Finally a conceptual data center design is developed and from which construction budget and time lines are put together.
Figure 1-1: Data Center Layers Page 2 of 29 www.PDHcenter.com PDH Course E173 www.PDHonline.org The modern Data center has various components. Figure 1.1 above shows all the components as different layers. All the layers will be discussed in detail in this course.
As shown graphically in this figure, “Applications, Database & Content” layer is the core layer which is the prime concern for corporation’s user’s point of view. But as we can see from the figure 1.1, for reliability and accessibility of this “core” layer there are several other layers need to be designed properly for Data center to be ideal.
Three important attributes of any good Data Center Design are scalability, flexibility and high availability.
The Data Center Design must support fast and seamless growth without major disruptions.
The Data Center Design must support new services without a major overhaul of its infrastructure.
The Data Center Design must minimize single point of failure and offer predictable uptime by incorporating concurrent maintainability and fault-tolerance against hard failures.
Data Center Feasibility Studies and Project Cost:
Data center project feasibility and cost budgeting is accomplished by applying Key
Design Criteria of the two main categories of the budget:
The Information Technology Infrastructure & Services (IT):
Each corporation has different Infrastructure in place depending upon the nature of the business. Spacing, Engineering and Security design depends a lot on primary use of the Data Center.
Infrastructure can be mix of various manufacturers for the same type of equipment, for example, Data servers can be from manufactures like Sun, IBM, Dell or Compaq.
This prompts for different Rack types and different power outlet requirement for each type of servers.
It is important to know the migration schedule from IT department of existing hardware for Flexibility.
Support Infrastructure and Services (Facility):
Location and size of the data center should be well coordinated with IT staff and facility maintenance staff.
Electrical and Air Conditioning: while selecting a location and space, Electrical and Air conditioning must be kept in mind. It should be feasible to add extra electrical and Air conditioning loads.
Maintenance staff: dedicated and trained maintenance staff should be available 24x7 to support data center issues.
A comprehensive data center inspection is needed to assess the ability of the support
infrastructure to provide continuous availability which include the following:
An evaluation of the present load condition A comparison to the capacity constraints Identification of critical deficiencies Potential downtime risks An assessment of the concurrent maintenance capacity of the site
Power and Cooling Systems Analysis:
A complete load profiling and reporting from simple spot-checking to week-long data
should be used to accomplish the following:
An evaluation of the present load condition A comparison to the capacity constraints Identification of critical deficiencies An assessment of the concurrent maintenance capacity of the site Redundant power supplies, 24 x7 backup facilities, multiple environment control systems
Business Continuity and Disaster Recovery:
A detailed assessment must be made while designing a data center for the following:
Identify Mission Critical Applications and Servers Staff availability in the event of Disaster Remote access to Applications
Data Center Site selection should be made based on all the above discussed factors.
All three types reside in a Data Center and often in the same Data Center facility, which generally is referred to as the corporate Data Center or enterprise Data Center. If the sole purpose of the Data Center is to support Internet-facing applications and server farms, the Data Center is referred to as an Internet Data Center.
Server farms are at the heart of the Data Center. In fact, Data Centers are built to support at least one type of server farm. Although different types of server farms share many architectural requirements, their objectives differ. Thus, the particular set of Data Center requirements depends on which type of server farm must be supported. Each type of server farm has a distinct set of infrastructure, security, and management requirements that must be addressed in the design of the server farm. Although each server farm design
and its specific topology might be different, the design guidelines apply equally to them all. The following sections introduce server farms.
Internet Server Farms As their name indicates, Internet server farms face the Internet. This implies that users accessing the server farms primarily are located somewhere on the Internet and use the Internet to reach the server farm. Internet server farms are then available to the Internet community at large and support business-to-consumer services. Typically, internal users also have access to the Internet server farms. The server farm services and their users rely on the use of web interfaces and web browsers, which makes them pervasive on Internet environments.
Two distinct types of Internet server farms exist. The dedicated Internet server farm, shown in Figure 2-2, is built to support large-scale Internet-facing applications that support the core business function. Typically, the core business function is based on an Internet presence or Internet commerce.
Figure 2-2 Dedicated Internet Server Farms
In general, dedicated Internet server farms exist to sustain the enterprise's e-business goals. Security and scalability are a major concern in this type of server farm. On one hand, most users accessing the server farm are located on the Internet, thereby introducing higher security risks; on the other hand, the number of likely users is very high, which could easily cause scalability problems.
Page 7 of 29 www.PDHcenter.com PDH Course E173 www.PDHonline.org The Data Center that supports this type of server farm is often referred to as an Internet Data Center (IDC). IDCs are built both by enterprises to support their own e-business infrastructure and by service providers selling hosting services, thus allowing enterprises to collocate the e-business infrastructure in the provider's network.
Intranet Server Farms
The evolution of the client/server model and the wide adoption of web-based applications on the Internet was the foundation for building intranets. Intranet server farms resemble the Internet server farms in their ease of access, yet they are available only to the enterprise's internal users. As described earlier in this chapter, intranet server farms include most of the enterprise-critical computing resources that support business processes and internal applications. This list of critical resources includes midrange and mainframe systems that support a wide variety of applications. Figure 2-3 illustrates the intranet server farm.
Notice that the intranet server farm module is connected to the core switches that form a portion of the enterprise backbone and provide connectivity between the private WAN and Internet Edge modules. The users accessing the intranet server farm are located in the campus and private WAN. Internet users typically are not permitted access to the intranet; however, internal users using the Internet as transport have access to the intranet using virtual private network (VPN) technology.
The Internet Edge module supports several functions that include the following:
Securing the enterprise network Controlling Internet access from the intranet Controlling access to the Internet server farms The Data Center provides additional security to further protect the data in the intranet server farm. This is accomplished by applying the security policies to the edge of the Data Center as well as to the applicable application tiers when attempting to harden communication between servers on different tiers. The security design applied to each tier depends on the architecture of the applications and the desired security level.
Extranet Server Farms
From a functional perspective, extranet server farms sit between Internet and intranet server farms. Extranet server farms continue the trend of using web-based applications, but, unlike Internet- or intranet-based server farms, they are accessed only by a selected group of users that are neither Internet- nor intranet-based. Extranet server farms are mainly available to business partners that are considered external yet trusted users. The main purpose for extranets is to improve business-to-business communication by allowing faster exchange of information in a user-friendly and secure environment. This reduces time to market and the cost of conducting business. The communication between the enterprise and its business partners, traditionally supported by dedicated links, rapidly is being migrated to a VPN infrastructure because of the ease of the setup, lower costs, and the support for concurrent voice, video, and data traffic over an IP network.
Many factors must be considered in the design of the extranet topology, including scalability, availability, and security. Dedicated firewalls and routers in the extranet are the result of a highly secure and scalable network infrastructure for partner connectivity, yet if there are only a small number of partners to deal with, you can leverage the existing Internet Edge infrastructure. Some partners require direct connectivity or dedicated private links, and others expect secure connections through VPN links. The architecture of the server farm does not change whether you are designing Internet or intranet server farms. The design guidelines apply equally to all types of server farms, yet the specifics of the design are dictated by the application environment requirements.
Corporate Data Center Corporate or enterprise Data Centers support many different functions that enable various business models based on Internet services, intranet services, or both. As a result, support for Internet, intranet, and extranet server farms is not uncommon. This concept was depicted in Figure 2-1, where the Data Center facility supports every type of server farm and also is connected to the rest of the enterprise network—private WAN, campus, Internet Edge, and so on. The support of intranet server farms is still the primary target of corporate Data Centers.
Enterprise Data Centers are evolving, and this evolution is partly a result of new trends in application environments, such as the n-tier, web services, and grid computing, but it results mainly because of the criticality of the data held in Data Centers.