Stories by: Logan Harbaugh

Virtualization is becoming increasingly important in the datacenter as a way to respond quickly to the varying server demands. Depending on time of day and day of the week, as well as events in progress and many other factors, loads on any given machine may vary by factors of 100 or 1,000 or more. Giving a server more or less computing power, running multiple instances of the same server for load balancing purposes, or allowing failover from one virtual instance to another are increasingly important capabilities.

Kemp Technologies' Load Master 1500 appliance sports three 10/100 ports and a basic set of load-balancing features, so it competes with the likes of the Barracuda 240 at the lower end of the market. Like the Barracuda line, the Kemp family includes other models with additional features such as SSL acceleration, higher capacity, active/passive high availability, and up to eight gigabit ports. The Kemp systems are also very affordable, and go further beyond the basics than the Barracuda systems.

Whether you call them application delivery controllers, application accelerators, application traffic managers, or just load balancers, the solutions for scaling out Web sites and improving the performance of Web applications have come a long way from their humble beginnings. The result is a great deal of choice in the marketplace, from bare-bones appliances with basic functionality to high-capacity switch-based systems that handle Web traffic in wildly sophisticated ways.

Known for anti-spam appliances and firewalls, Barracuda Networks is relatively new to the load-balancing game. The company's series of load balancers span the range from a basic 10-server model that starts at US$1,995 to an enterprise model with an entry price of US$8,999 and that supports an unlimited number of servers and virtual clusters. As the models increase in size and cost, they also add some nice features. These include active/passive high availability that is extremely easy to set up, the ability to route traffic based on the type of service (layer 7 load balancing), cookie persistence for e-commerce (and other applications that need to identify users from one session to the next), and hardware-based SSL acceleration.

Viruses and spam both pose an increasing threat these days, and not just to your data or productivity. Rather than hackers trying to break security systems for their own amusement, most current threats are financially motivated and can cost a company millions. And with viruses and phishing attacks growing increasingly more criminal in intention every day, securing financial, customer, and other critical data requires a rock-solid system of defense.

Microsoft Windows Server 2003 supports running Exchange in a cluster of as many as eight nodes, and the functionality is great. If any of the nodes fails or is brought down for maintenance, the Exchange server is simply moved to one of the other nodes in the cluster. The interruption to handling incoming mail or client requests is minimal, amounting to the time it takes for Exchange services to come up when you boot a server. So why not use native clustering?

Basic e-mail encryption between two users isn't terribly difficult to implement. Free add-ons to the more popular e-mail clients provide for easy encryption and decryption of messages. It's exponentially more difficult, however, to deploy encryption to hundreds or thousands of clients, which typically involves supplying the software to recipients at the other end of every encrypted connection, coordinating the exchanges of keys, and training users on client-side encryption software.

Load balancers used to be fairly simple, distributing user requests from the Internet to a group of servers instead of just one. Between the drive to differentiate themselves and the increasing sophistication of Web sites and enterprise intranets, current load balancers add a plethora of additional features, from SSL off-loading to Web application acceleration to content inspection and security filters that guard against hackers exploiting known vulnerabilities to gain control of Web servers or applications.

Administrators often battle with end users over the amount of space they use on mail and file servers. Users would like to keep everything they might need, while administrators would like to avoid buying more disks and upgrading servers to handle huge inboxes and home directories.

In a world where compliance encourages companies to save everything, emerging standards promise flexibility and control for heterogeneous storage environments.

Geared to the SMB market, WatchGuard Technologies's Firebox X series offers a feature set comparable to more expensive firewalls -- along with some of the accompanying setup and administration complexities of enterprise firewalls.