HOB Desktop-on-Blade: Blade Servers and Windows XP/Vista

With the HOB RD VPN software suite, enterprises can access more than just terminal servers; they can also access single-user solutions like Windows XP Professional or Windows Vista. Hereby, our solution uses the Microsoft standard “Remote Desktop Protocol” (RDP). Enterprises are now using HOB Desktop-on-Blade to implement some of their new remote access projects with blade servers instead of relying solely on the classic Windows Terminal Server technology. 

Sample scenario for HOB RD VPN with HOB Desktop-on-Blade

How can a Blade Server Complement a Terminal Server Solution?

There are several reasons why a company might supplement a classical TS farm with a blade server solution. One of these, for example, would be to reduce the total cost of ownership and benefit from the potentially great savings on administration and maintenance. There are other, often overlooked reasons to go with this solution: A major advantage of using a blade server farm is that older applications, or custom-written (home-grown) applications that could not be effectively deployed in a Terminal Server multi-user environment can be used in a multi-user environment based on blade servers. This saves the costs associated with reprogramming older/custom applications or having to replace them entirely.

How do Blade Servers, Windows XP/Vista and HOB Software Work Together?

Companies use blade servers when they need a large number of identical servers. A “blade” is a board with its own CPU, and has the full functionality of a PC. Thanks to the laptop technology used in their manufacture, they are very small and require little ventilation, thus many of them (up to 300!) can be fit into a single cabinet. The individual blades in the cabinet form the blade server, and, usually, they all use a common network environment. The blades in a blade server are connected via a bus system, and new blades can be added, or existing blades exchanged, very easily. This hot-swap ability is just one of the many benefits resulting from a blade server solution. 

With this blade server solution, a company installs Microsoft Windows XP Professional/Vista on each blade. A remote connection over RDP can now be established to every XP/Vista. Only one user at a time then works with the programs installed there. Software programs that are usually run on the Terminal Server are now installed on each blade. There are software tools available that can automatically configure all of the blades identically.

The market for blade server solutions is still relatively young; HOB, however, has already developed a powerful blade server solution. First, HOB solved the problem of making an idle blade with Windows XP/Vista available to other users. To do this, the HOB Blade Balancer was developed. This software reports the blade as being free when no user is currently logged on or no disconnection has taken place. The last is important, because if a user has been inadvertently disconnected from the blade, e.g., due to a faulty communication line, the HOB Blade Balancer detects a disconnect and the HOB solution reserves this blade for a reconnect to the same user. This way, if a blade is in use, the user cannot be “kicked off” by another user attempting to logon, and an idle blade can be freed for the next user, thereby getting maximum performance from your blade server.

The HOB Blade Balancer has to be installed on each blade in the server. It sends its information to the HOB WebSecureProxy. This proxy can also handle the following situation: User 1 has just made a logon request for a blade, but hasn’t yet entered the logon data. User 2 was therefore able to logon to the “free” blade before User 1. If User 1 were to enter the logon data now, with previous blade server solutions, User 2 would be automatically disconnected. With the HOB solution, however, as soon as a blade has responded to a logon request by returning that it is free, it is reserved until the logon process has been completed. This way, potential conflicts are avoided from the beginning.

The WebSecureProxy is a component of the HOB SSL encryption software HOBLink Secure, and is configured via XML. It is highly recommended to use encryption for remote connections over the Internet.

When several WebSecureProxies are in use (in order to avoid a Single-Point-of-Failure), a mechanism similar to the HOB Blade Balancer allows the different WSP’s to “know” which blades are occupied or being logged onto, in order to prevent the same blade from being assigned by more than one WebSecureProxy.

Why Use a Blade Server Farm?

	Reduced Total Cost of Ownership through reduced space, power, cabling and maintenance requirements
	The savings on license fees, client access licenses, etc. is greater than the cost of the hardware (for example: a blade server farm with 300 blades that is used by 600 users still only requires 300 Client Access licenses, whereas a WTS server farm with 600 users requires 600 Client Access licenses!)
	Large savings potential for administration and maintenance
	Hot-swap ability – Blades can be exchanged without affecting other servers

Why Use A Blade Server Farm with HOB Software?

	Idle blades can be assigned to any user who requires one, a blade in use is reserved for the active user alone – Only the HOB Blade Balancer can do this!
	The HOB Blade Balancer provides maximum scalability per user
	Permanent backup-solution available
	When a company deploys many different applications, compatibility with the WTS solution and/or multi-user capability can be difficult to achieve – With the HOB Blade Balancer, this is no problem.

Whether an enterprise prefers to use a classic Windows Terminal Server solution with HOBLink JWT and HOBLink Secure, or decides to apply blade server technology, depends on the enterprise and the work it wants done. Specialists from HOB or one of the HOB partners can help you in making the best choice

Whitepaper: HOB Desktop-on-Blade  (PDF format)

Case study: University of Wisconsin-Green Bay

 For technical information please contact our support department.

webmaster@hobsoft.com, Last Updated: 06-May-08