Eliminating Single Points of Failure From Your Private Cloud
— Brought to you by 2X Cloud Computing guest blogger Brien M. Posey —
When an organization deploys a private cloud, that private cloud quickly becomes an indispensable, mission critical infrastructure component. That being the case, it is important to construct the private cloud in a way that avoids the potential for a single point of failure. Although it is impossible to delve into a comprehensive discussion of fault tolerance within the confines of a blog post, I wanted to take the opportunity to discuss some strategies for eliminating single points of failure within your private cloud.
Eliminating single points of failure means implementing redundancy for critical system components. In the case of a private cloud the redundant components that you will need and your overall fault-tolerant strategy will depend on what the private cloud is designed to and on the ways in which clients will connect to the private cloud.
Assuming that clients are connecting from the Internet, those clients generally connect to a web portal which then forwards the connection to a Secure Client Gateway. If the web portal or the Secure Client Gateway were to drop off-line then connectivity from the Internet would become impossible. As such, it is important to have redundant web portals and redundant Secure Client Gateways.
If fault tolerance is the only goal than the organization can get by on two web portals and two Secure Client Gateways. Often times however, this redundant architecture is also used to achieve a degree of scalability that allows for a greater number of client connections than a single web portal and client Gateway would be able to handle. Achieving the scalability involves grouping web portals and Secure Client Gateways into a Network Load Balancing Client Access Group.
Although the NLB Client Access Group provides both scalability and fault tolerance, is a good idea to include at least one more web portal and one more Secure Client Gateway than what is actually needed. That way if a web portal for a Secure Client Gateway were to fail then the NLB Client Access Group would still have sufficient resources to manage the inbound connections.
The Secure Client Gateway provides connectivity to a component known as the Publishing agent. Users who are connecting to the private cloud directly through the Local Area Network can connect directly to the Publishing agent without having to pass through the NLB Client Access Group.
Regardless of whether clients are connecting locally or from across the Internet, you don’t want the publishing agent to become a single point of failure. The easiest way to protect against this type of situation is to implement a primary publishing agent and a backup publishing agent.
The final component in this type of architecture is the Microsoft Terminal Server. Once again, redundancy can be achieved by simply deploying multiple terminal servers.
In any private cloud environment it is critically important to use redundant resources as a way of insulating the private cloud against server level failures. By doing so it becomes possible to make your private cloud highly reliable.
About Brien M. Posey
Brien Posey is a ten time Microsoft MVP with two decades of IT experience. Prior to becoming a freelance technical writer, Brien served as CIO for a national chain of hospitals and healthcare facilities. He has also worked as a network administrator for some of the nation’s largest insurance companies and for the Department of Defense at Fort Knox.
Since going freelance in 2001, Brien has become a prolific technical author. He has published many thousands of articles and numerous books on a wide variety of topics (primarily focusing on enterprise networking). In addition to his writing, Brien has provided consulting services to clients and speaks at IT events all over the world.
About 2X Software
2X Software is a global leader in virtual desktop and application delivery, remote access and cloud computing solutions. Thousands of enterprises worldwide trust in the reliability and scalability of 2X products. 2X offers a range of solutions to make every company’s shift to cloud computing simple and affordable.