This chapter covers the following topics:
Types of server farms and data centers
Topologies of data centers
Fully redundant Layer 2 and Layer 3 designs
Fully redundant Layer 2 and Layer 3 designs with services
This chapter focuses on three key properties of data center architectures: scalability, flexibility, and high availability. Data centers are rapidly evolving to meet higher expectations for growth, consolidation and security. While traditional Layer 2 and Layer 3 designs have not changed dramatically in recent years, stringent uptime and service availability requirements, along with new technology and protocols, make design efforts more challenging and demanding.
The requirements for scalability, flexibility and high availability can be summarized as follows:
ScalabilityThe data center must support rapid and seamless growth without major disruptions.
FlexibilityThe data center must support new services without major infrastructure overhaul.
High availabilityA data center should not have a single point of failure and should allow for predictable uptime (related to hard failures).
A hard failure is a failure where a component must be replaced to return to a stable operating state.
Scalability translates into the ability to support rapid growth in performance, the number of devices located in the data center, and the quantity and quality of services offered. Higher performance implies tolerance to very short-term changes in traffic patterns without packet loss and longer-term plans that show data center capacity growth trends.
Hosted appliance scalability refers to the ability to seamlessly add multiple ports to servers, routers, switches, and other service devices, such as server load balancers, firewalls, IDSs, and SSL offloaders. Higher density also includes slot density because the number of slots ultimately determines the potential growth of the system.
Flexibility translates into designs that can adapt to new service offerings without the need for complete architecture redesign or drastic changes beyond normal scheduled maintenance. The flexibility approach is a modular design where the features of the modules are known and the steps to add more modules are simple.
High availability translates into a fully redundant architecture where all possible severe failures are predictable and deterministic. This means that the failure of each potential component has a predetermined failover time and recovery time and that the worst possible failure scenario is still within the acceptable failover limits and within the requirements measured from an application availability perspective. This means that while the failure and recovery time of a network component should be predictable and known, the more important time relates to the user's perception of the time required to recover an application service.
After a failure, recovery time can be measured from a layer 2 environment perspective (spanning tree) or from a layer 3 perspective (routed network), but the availability of the application is ultimately what matters to the user. If the failure is such that the user's connection times out, network convergence will not meet the application's requirements, regardless of the convergence time. In data center design, it is important to measure recovery time from a network and application perspective to ensure predictable network recovery time for the customer (application service).
Figure 4.1 provides an overview of a data center that as an object contains numerous building blocks and components of a larger corporate network architecture.
This book is mainly concerned with the engineering of application environments and their integration into the rest of the corporate network. Different types of server farms support application environments, but this book focuses on understanding, designing, implementing, and maintaining server farms that support intranet application environments. The actual engineering of different types of server farms Internet, extranet, and intranet server farms do not differ much from one type to another; however, their integration with the rest of the architecture is different. Design choices that differ for each type of server farm are a result of their main functional purpose. This leads to a specific location for their placement, security considerations, redundancy, scalability and performance. In addition to server farm concepts, a brief discussion of server farm types further clarifies these points.
The illustrations in this chapter contain a large selection of Cisco icons. See the "Icons used in this book" section (just before the "Introduction") for a list of icons and their descriptions.
Figure 4-1 Data center topology overview
As shown in Figure 4.1, there are three different types of server farms:
All three types are found in the data center and often in the same data center facility, which is generally calledcorporate data centerfromcorporate data center. If the sole purpose of a data center is to support Internet applications and server farms, the data center becomes oneInternet data center.
Server farms are the heart of a 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 common architectural requirements, their goals differ. So the specific set of requirements for a data center depends on what type of server farm needs to be supported. Each type of server farm has its own set of infrastructure, security, and management requirements that must be met when designing a server farm. Although each server farm design and its specific topology may differ, the design guidelines apply to all server farms. Server farms are introduced in the following sections.
Internet server farms
As their name suggests, Internet server farms monitor the Internet. This means that users accessing server farms are primarily located somewhere on the Internet and use the Internet to reach the server farm. Internet server farms are then available to the wider Internet community and support business-to-consumer services. Internal users usually also have access to Internet server farms. Server farm services and their users depend on the use of web interfaces and web browsers, making them ubiquitous in Internet environments.
There are two different types of Internet server farms. A dedicated Internet server farm, shown in Figure 4-2, is built to support the large Internet-facing applications that support the core business. Typically, a company's core business is based on an online presence or online store.
In general, dedicated Internet server farms exist to support an enterprise's e-business goals. Architecturally, these server farms follow the data center architecture presented in Chapter 1, "Data Center Overview," but the details of each layer and the required layers are determined by the requirements of the application environment. Security and scalability are major concerns in this type of server farm. On the one hand, most of the users accessing the server farm are on the Internet, which poses a greater security risk; on the other hand, the number of likely users is very high, which can easily cause scalability problems.
A data center that supports this type of server farm is often called an Internet Data Center (IDC). IDCs are built by both companies to support their own e-business infrastructure and by service providers that sell hosting services, enabling companies to integrate e-business infrastructure into the service provider's network.
The next type of Internet server farm, shown in Figure 4-3, is built to support Internet-based applications with business Internet access. This means that the infrastructure that supports server farms is also used to support business users' Internet access. These server farms are usually located in the demilitarized zone (DMZ) because they are part of the corporate network, yet they can be accessed via the Internet. These server farms are called DMZ server farms, to distinguish them from dedicated Internet server farms.
Figure 4-2 Dedicated Internet server farms
These server farms support services such as e-commerce and are access portals for generic applications used by Internet and intranet users. Scalability considerations depend on how large the expected user base is. Security requirements are also very strict as security policies are aimed at protecting server farms from outside users while keeping the corporate network secure. Note that under this model, the corporate network supports the campus, private WAN, and intranet server farm.
Note that Figure 4-3 shows a small number of servers located on a segment outside the firewall. Depending on the requirements, a small number of servers could become hundreds or thousands, which would change the topology to include a set of Layer 3 switches and as many Layer 2 switches to connect the servers as needed.
Figure 4-3 Server farm DMZ
Intranet server farms
The evolution of the client/server model and the widespread use of web-based applications on the Internet created the basis for the construction of intranets. Intranet server farms are similar to Internet server farms in terms of ease of access, but are accessible only to internal company users. As described earlier in this chapter, intranet server farms contain most of the critical computing resources that support business processes and internal applications. This list of critical resources includes intermediate and mainframe systems that support a wide variety of applications. Figure 4-4 illustrates an intranet server farm.
Note that the intranet server farm module is connected to core switches that are part of the enterprise backbone and provide connectivity between the private WAN and the Internet Edge module. Users accessing the intranet server farm are located on campus and in the private WAN. Internet users generally do not have access to an intranet; however, internal users using the Internet as a means of transportation can access the intranet using Virtual Private Network (VPN) technology.
Figure 4-4 Intranet server farms
The Internet Edge module supports several features, including the following:
Secure your business network
Management of Internet access from the intranet
Access control to Internet server farms
The data center provides additional security for additional data protection in the intranet server farm. This is achieved by applying security policies at the edge of the data center and at the applicable application layers when trying to strengthen communication between servers at different levels. The security design applied to each layer depends on the application architecture and the desired level of security.
The access requirements of business users dictate the size and architecture of server farms. The growing number of users, as well as the increased load imposed by rich applications, increases the demand for server farms. This requirement forces scalability to be a critical design criterion, along with high availability, security, and manageability.
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 applications, but unlike Internet or intranet server farms, they are only available to a select group of non-Internet or intranet-based users. Extranet server farms are primarily available to business partners who are considered remote but trusted users. The main purpose of extranets is to improve communication between companies by enabling a faster exchange of information in a user-friendly and secure environment. This reduces time to market and business costs. Communication between an enterprise and its business partners, traditionally supported by dedicated connections, is rapidly migrating to VPN infrastructure due to ease of installation, lower costs and support for simultaneous voice, video and data traffic over the IP network.
As explained earlier, the extranet concept is analogous to IDC in that the server farm is located at the edge of the corporate network. Since the purpose of an extranet is to provide server farm services to confidential remote end users, there are special security considerations. These security considerations mean that business partners have access to a subset of the company's applications, but cannot access the rest of the company's network. Figure 4-5 shows an extranet server farm. Note that the extranet server farm is accessible to internal users, but access from the extranet to the intranet is prevented or highly secured. Usually, access from the extranet to the intranet is restricted by the use of firewalls.
When designing an extranet topology, many factors must be considered, including scalability, availability, and security. Dedicated firewalls and extranet routers are the result of a highly secure and scalable network infrastructure for connecting partners, but if you only have a small number of partners to deal with, you can leverage your existing Internet Edge infrastructure. Some partners require a direct connection or dedicated private connections, while others expect secure connections via VPN connections. Server farm architecture does not change whether you are designing Internet or intranet server farms. Design guidelines apply equally to all types of server farms, but design details are dictated by the requirements of the application environment.
Figure 4-5 Server farm extranet
The following section discusses the types of data centers that have been briefly mentioned in this section.
Internet data center
Internet data centers (IDCs) are traditionally built and managed by service providers, but companies with an e-commerce business model also build and manage IDCs. The architecture of enterprise IDCs is very similar to service provider IDCs, but scalability requirements are typically lower because the user base is typically smaller and has fewer services compared to SP IDCs that host multiple clients.
In fact, the architecture of the IDC is the same as that shown in Figure 4.2. An interesting consideration of enterprise IDCs is that, if the business model requires it, the facilities used by the data center may be located in the service provider's data center, but they remain under the control of the enterprise. This is typically done to reduce the costs associated with building a server farm and shorten time to market by avoiding building an in-house data center from the ground up.
The company's data center
Enterprise data centers support many different functions that enable different 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 is illustrated in Figure 4-1, where a data center facility supports any type of server farm and is also connected to the rest of the corporate network—private WAN, campus, Internet Edge, etc. Supporting intranet server farms is still the primary purpose of corporate data centers.
Enterprise data centers are evolving, and this evolution is partly the result of new trends in application environments, such as n-tier, web services, and network computing, but mostly stems from the critical nature of data stored in data centers.
The following section discusses typical topologies used in data center architecture.
Difference Between Server Farms and Data Centers
You can think of the server farm as a collection of computers and the data center as a place for those computers. Server farms don't need a data center.
There can be two types of Internet server farms:•Dedicated internet server farms•Demilitarised zone (DMZ) server farmsDedicated Internet server farms:The dedicated internet server farm is designed to supportlarge-scale Internet-facing applications.What type of servers are used in data centers? ›
- Web Server.
- Database Server.
- Email Server.
- Web Proxy Server.
- DNS Server.
- FTP Server.
- File Server.
- DHCP Server.
Data centers are made up of three primary types of components: compute, storage, and network.What is the difference between server farm and cluster? ›
The key differences between a cluster and a server farm are the behavior when a failure occurs, ease of management, and scalability of operations: A cluster allows an EVS to be automatically migrated among cluster nodes in the event of a failure, and management of all nodes in the cluster is centralized.What are the three 3 types of server? ›
Today's servers are primarily available in three forms: racks, blades and mainframes. The majority of IT teams turn to rack and blade servers to meet their server requirements. Some teams opt for mainframe computers to handle their workloads, although not nearly to the extent of rack and blade servers.What is the purpose of server farms? ›
What is a server farm? Also known as a server cluster, a server farm is a large number—up to thousands—of servers grouped together to provide better functionality and accessibility. By keeping the servers close together, the manager of a server farm can achieve centralized control and economy of scale.What are the three common server types? ›
- Web server. An open-source web server is used for accessing the world wide web through public domain software. ...
- Proxy server. ...
- Virtual machine (VM) ...
- File transfer protocol (FTP) server. ...
- Application server. ...
- File server. ...
- Database server. ...
- 8. Mail server.
Data center needs vary depending on their structure, physical limitations, density requirements and more. Here are four common data center types including onsite, colocation facilities, hyperscale, and edge data centers, as well as their use cases and industry trends.What are the 5 elements of data center? ›
- Power. Data centers use more power than some developed nations do. ...
- Cooling. Servers and other equipment in data centers generate a lot of heat. ...
- Security. ...
- Scalability. ...
- Location. ...
- Get It Right!
- Public data. Public data is important information, though often available material that's freely accessible for people to read, research, review and store. ...
- Private data. ...
- Internal data. ...
- Confidential data. ...
- Restricted data.
The function of a server is to receive, store, and share data. Some of the most common types of servers include web servers, print servers, file servers, mail servers, application servers, and many more.How many types of servers are? ›
Database servers, print servers, mail servers, file servers, application servers, web servers, and game servers are a few examples of servers. The request-response paradigm, in which a client submits a request to the server, is the one used to create client-server systems most frequently.How many servers are required in data center? ›
How many servers does a data center have? On the lower end, a small, in-house data center could somewhere near 1000 servers. Most data centers are quite large, however, and a more typical number is close to 100,000 servers.What is the basic structure of data center? ›
It consists of a network of computing and storage resources such as routers and servers that enable the provision of data and applications. In this way, companies or Internet service providers can manage their entire IT infrastructure and data processing efficiently and securely.What are the 3 main purposes of a datacenter? ›
The Role of the Data Center
Data storage, management, backup and recovery.
Data center design is the process of modeling and designing a data center's IT resources, architectural layout and entire infrastructure. It enables the logical conception of a data center prior to development or implementation in an organization or IT environment.What is another name for server farm? ›
A server farm is also known as a server cluster or computer ranch.Is a server farm a data center? ›
With over 1 million square feet of operating space between our facilities, Serverfarm data centers offer optimal connectivity, colocation and hybrid IT services. From North America's most sought-after markets to emerging regions across Europe and the Middle East, Serverfarm data centers deliver fast, scalable capacity.How many servers in a cluster? ›
Those who have experienced the complexities and gotchas of two-node clusters know that a minimum of three servers is the best way to create a cluster that is both reliable and easy to manage.
|Client server architecture||Peer-to-peer architecture|
|It has specific clients and servers.||There is no differentiation between clients and servers.|
|It has centralized data management.||It has its own data and applications.|
A Server Farm is a set of computer servers that are maintained and housed in one location. Server farms, also called data farms, generally have backup servers, which can take over the role of primary servers in the event the servers fail.What is the biggest data center in the world? ›
The Inner Mongolia Information Park is the world's largest data center, with 10,763,910 (10.7 million) square feet, and sits on the Beijin-Tianjin economic circle radiation belt.Who is the largest data center provider? ›
|#||Data Center Company||Geography|
|1||Amazon Web Services (AWS)||Global|
|3||Google Cloud Platform (GCP)||Global|
|4||Meta Platforms (Facebook)||North America, Europe|
4 Key Components of a Server: CPU, Memory, Hard Disk & RAID Card.What is server with example? ›
server, network computer, computer program, or device that processes requests from a client (see client-server architecture). On the World Wide Web, for example, a Web server is a computer that uses the HTTP protocol to send Web pages to a client's computer when the client requests them.What are the functions of a server? ›
The function of a computer server is to store, retrieve and send or "serve" files and data to other computers on its network.How are datacenters classified? ›
Data centers are ranked under various Data Center Tiers basis the reliability, facilities, uptime, security, etc. they provide. This classification helps enterprises choose a data center basis their requirements. Data centers are certified by Uptime institute's - standard tier classification system or TIA/942 standard.What are the two classification of data centers? ›
Tier 1: A Tier 1 data center has a single path for power and cooling and few, if any, redundant and backup components. It has an expected uptime of 99.671% (28.8 hours of downtime annually). Tier 2: A Tier 2 data center has a single path for power and cooling and some redundant and backup components.What is a Tier 3 or 4 data center? ›
Tier 3: A data center with multiple paths for power and cooling, and redundant systems that allow the staff to work on the setup without taking it offline. This tier has an expected uptime of 99.982% per year. Tier 4: A completely fault-tolerant data center with redundancy for every component.
Hence, information systems can be viewed as having six major components: hardware, software, network communications, data, people, and processes. Each has a specific role, and all roles must work together to have a working information system.What is a Tier 5 data center? ›
Tier 5 Platinum not only encompasses the resiliency and redundancy in other data center ratings systems, but also evaluates more than 30 additional key elements, such as long-term power system capabilities, the number of available carriers, zero roof penetrations, the location of cooling system lines in or above the ...What are the four element in data? ›
Four Elements of Data: Volume, velocity, variety, and veracity.What are the 7 types of data? ›
- Integer. Integer data types often represent whole numbers in programming. ...
- Character. In coding, alphabet letters denote characters. ...
- Date. This data type stores a calendar date with other programming information. ...
- Floating point (real) ...
- Long. ...
- Short. ...
- String. ...
A server is a computer program or device that provides a service to another computer program and its user, also known as the client. In a data center, the physical computer that a server program runs on is also frequently referred to as a server.What is the difference between a server and a service? ›
Difference Between Web Server and Web Service
The main difference between a web server and a web service is that a web server is responsible for hosting websites and providing access to web content, while a web service is a software application that provides a service over the internet.
According to network size, servers are divided into Workgroup Servers, Department Servers, and Enterprise Servers. It is used for small networks with a few dozen of computers or with low requirements for processing speed and system reliability, with relatively low hardware configuration.What are 13 servers? ›
The authoritative name servers that serve the DNS root zone, commonly known as the “root servers”, are a network of hundreds of servers in many countries around the world. They are configured in the DNS root zone as 13 named authorities, as follows.What are the two most popular servers? ›
Nginx and Apache are undoubtedly the two most used web servers worldwide. Each of them holds about a third of the market. According to W3Techs' data, Nginx holds about 34.2% of the market and Apache about 31.2% — 28.9% and 22.6% respectively according to Netcraft's data.
- Decide what service request (or requests) your server will handle. If your server handles more than one service request, your server needs a service function for each request. ...
- Decide whether the server should use 24- or 31-bit addressing. ...
- Select a name for the server.
What is a server farm? Also known as a server cluster, a server farm is a large number—up to thousands—of servers grouped together to provide better functionality and accessibility. By keeping the servers close together, the manager of a server farm can achieve centralized control and economy of scale.What are the three types of data centers? ›
- Colocation. A colocation center — also known as a “carrier hotel” — is a type of data center where you can rent equipment, space, and bandwidth from the data center's owner.
- Enterprise. ...
- Cloud. ...
- Edge Data Center. ...
- Micro Data Center.
A server farm or server cluster is a collection of computer servers, usually maintained by an organization to supply server functionality far beyond the capability of a single machine. They often consist of thousands of computers which require a large amount of power to run and to keep cool.What are the characteristics of a server farm? ›
A server farm is a group of computer servers that are housed in one facility. Server farms can contain anywhere from dozens to thousands of racks of servers operating the same applications and systems. Load balancers distribute traffic throughout the server farm to maximize efficiency.Where are server farms used? ›
Its cutting-edge design sets a new standard for data centers around the world. Server farms are used for efficient data storage and management. The bigger it is, the more data it can store!What are the benefits of a server farm? ›
- consistent and reliable tools to manage many servers at once (or one by one)
- several monitoring capabilities.
- automatic, possibly encrypted backups.
- working MTA configuration (your servers are now able to send emails)
Data farming is the process of using designed computational experiments to “grow” data, which can then be analyzed using statistical and visualization techniques to obtain insight into complex systems. These methods can be applied to any computational model.What is a data farm used for? ›
data farming, in contrast, is a controlled method of data analysis. It involves utilizing simulations to create large amounts of data and extracting insights through experimentation. Data farmers control the simulations by adjusting parameters and experimenting with different models and designs.What are the four main types of data centers? ›
Data center needs vary depending on their structure, physical limitations, density requirements and more. Here are four common data center types including onsite, colocation facilities, hyperscale, and edge data centers, as well as their use cases and industry trends.