Article: Computer Science
Define and describe IaaS and identify IaaS solution providers.
Define and describe colocation.
Define and describe system and storage redundancy.
Define and describe cloud-based network-attached storage (NAS) devices and identify solution providers.
Define and describe load balancing and identify cloud-based solution providers.
Describe the pros and cons of IaaS solutions.
Learning Objectives
An IaaS provider makes all of the computing hardware resources available, and the customers, in turn, are responsible for installing and managing the systems, which they can normally do, for the most part, over the Internet.
IaaS Defined
What Data Centers Must Provide
Access to high-speed and redundant Internet service
Sufficient air conditioning to eliminate the heat generated by servers and disk storage devices
Conditioned power with the potential for uninterrupted power supply in the short term and long term through the use of on-site diesel powered generators
Fire suppression systems
Administrative staffing to support hardware, networks, and operating systems
Bottom Line: Data Centers are Expensive
Co-located Data Centers
To reduce the risk of a single point of failure, companies often create a duplicate data center at a remote location.
Should one of the data centers fail, the other can immediately take over operations.
Unfortunately, the second data center will increase the company’s costs—essentially doubling them—because there are duplicate servers, storage devices, network equipment, Internet access, and staffing.
Co-located Data Center
What Co-located Systems Accomplish
Makes the company less susceptible to fire, acts of God, and terrorism
Improves performance through a distributed workload
Makes the company less susceptible to downtime due to power loss from a blackout or brownout
IaaS solutions allow smaller companies to eliminate the need for their own on-site data center
IaaS Solutions May Support Many Different Companies
Load Balancing
Across the web, sites experience a wide range of network traffic requirements.
Sites such as Google, Yahoo!, Amazon, and Microsoft experience millions of user hits per day. To handle such web requests, the sites use a technique known as load balancing, to share the requests across multiple servers.
Load Balancing Continued
Load balancing uses a server to route traffic to multiple servers which, in turn, share the workload.
Load Balancing and Replicated Databases
Load balanced systems, for data redundancy, often replicate databases on multiple servers.
Each database, in turn, will send data updates to the other to maintain data synchronization between the servers.
Cloud-Based Data Replication
Using cloud-based NAS devices and cloud-based databases, companies can replicate key data within the cloud.
Real World: Rackspace IaaS
Rackspace has emerged as one of the largest players in the IaaS market. Rackspace offers a set of solutions that include cloud hosting, managed hosting (including 24/7 data-center like management), and hybrid solutions that combine the cloud and managed services.
Within minutes, from the Rackspace website an administrator can select a solution that deploys from 1 to 50 servers. Larger configurations are available.
Rackspace Continued
Today Rackspace offers cloudbased solutions to hundreds of thousands of clients. Rackspace houses its data centers at very large facilities located around the world.
With respect to the cloud, Rackspace offers pay as you go scalability, with on-demand storage and load balancing. Beyond cloud hosting, Rackspace provides solutions for cloud-based e-mail, Exchange hosting, file sharing, backups, and collaboration.
Network Attached Storage (NAS)
Cloud-based NAS devices present cloud-based storage as mountable devices, which may be replicated in the cloud to meet a company’s data redundancy needs.
Real World: Nirvanix IaaS
The Nirvanix IaaS provides cloud-based NAS, which is accessible through the CloudNAS file system.
Advantages of IaaS
Elimination of an expensive and staff-intensive data center
Ease of hardware scalability
Reduced hardware cost
On-demand, pay as you go scalability
Reduction of IT staff
Suitability for ad hoc test environments
Allows complete system administration and management
IaaS Server Types
Physical server: Actual hardware is allocated for the customer’s dedicated use.
Dedicated virtual server: The customer is allocated a virtual server, which runs on a physical server that may or may not have other virtual servers.
Shared virtual server: The customer can access a virtual server on a device that may be shared with other customers.
IaaS Server Types Continued
Within an IaaS environment, customers can allocate various server types.
Data Center Technology
Virtualization
Standardization and Modularity
Automation
Remote Operation and Management
High Availability
Security-Aware Design, Operation, and Management
Facilities
Computing Hardware
Storage Hardware
(Erl, 2014)
Storage Technologies
Hard Disk Arrays
I/O Caching
Hot-Swappable Hard Disks
Storage Virtualization
Fast Data Replication Mechanisms
Network Storage Devices
Storage Area Networks (SAN) – dedicated network
Network Attached Storage (NAS) – device connected to network
(Erl, 2014)
Network Hardware
Carrier and External Network Interconnection – LAN/WAN
Load Balancing and Acceleration
LAN Fabric – High performance and redundant connectivity
SAN Fabric – Used to connect servers to storage devices
NAS Gateways – connection points for NAS storage devices
(Erl, 2014)
Key Terms
References
Primary:
Jamsa, K. A. (2013). Cloud computing: SaaS, PaaS, IaaS, virtualization, business models, mobile, security and more. Burlington, MA: Jones & Bartlett Learning.
Secondary:
Erl, T., Mahmood, Z., & Puttini, R. (2014). Cloud computing: concepts, technology, & architecture. Upper Saddle River, NJ: Prentice Hall.
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