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.
The Barracuda Load Balancer 340 was easy to install, with a clean, quick initial configuration. The default installation uses keyboard, mouse, and monitor, but there's a procedure to apply a default IP address for initial configuration by browser, if you prefer. Once that first configuration is done, setting up clusters is straightforward, although not quite as easy as with some of the more mature products. For instance, the dialog for adding servers to a cluster applies to only one server at a time; you have to close, then open another box to add each additional server. Some of the other load balancers will let you add multiple servers in a single dialog box -- not a big deal, but typical of a less mature interface. A convenient auto-discovery feature finds available servers and lets you add them to a cluster with a click. The Barracuda also does a good job with performance monitoring and reports, although with not quite as many options as, say, the F5 BIG-IP.
The Barracuda 340 has two Ethernet ports, as do the less expensive 240 and pricier 440. These are gigabit ports for the 340 and 440, and 10/100 for the 240. These models should do the trick for most small load-balancing setups. For those setting up internally facing Web sites for application delivery or other applications that require higher port counts, the Barracuda 640 offers 12 gigabit ports. The 240 is limited to 10 physical servers, the 340 to 35, the 440 to 50, and the 640 to 250 servers. All models include an intrusion prevention feature that should block DoS attacks and other TCP/IP based attacks such as SYN floods.
Setting up the additional features beyond basic load balancing is also easy. The Barracuda is not as configurable as the F5 or Juniper solutions, for instance, but it's easier to get started with. Health checking offers some basic options (such as pinging an IP address or other TCP port numbers to see if an SSL port or database is available, for instance), and Barracuda will write custom health checks for anyone who has a support subscription. F5 and Juniper allow you to create custom health checks rather than relying on customer support people to create one for you. The end result is the same, but you aren't dependent on the goodwill of the vendor.
The more extensive programmability of the higher-end systems also lets you create more complex rules for managing Web traffic. For instance, you might have a rule that, based on source IP address, sends any traffic from China to a Chinese-language version of the Web site. This kind of advanced routing is not possible with the Barracuda.
As with the other products I've tested, I tried out the Barracuda 340 by setting up a virtual cluster of several servers running a demo version of an e-commerce site. I then used an Ixia 400T traffic generator and IxLoad software to simulate a large number of users accessing the virtual Web site, then compared the loads generated on each Web site. The 340 was able to keep actual loads on the servers consistent even though their processing power varied considerably. I then enabled a number of features such as SSL and persistent sessions, and attempted to overload the unit by simulating many simultaneous users. As with the other solutions I've tested, this was only possible with artificially small sessions. When simulating actual traffic, the gigabit connection became saturated before the limitations of the device were reached.
The Barracuda 340 and its brethren belong to the class of basic load balancers rather than Web accelerators. Lacking compression, caching, and TCP optimization features, they are not the most capable units I've tested, but they will do the job for basic server farms and even basic e-commerce applications. They aren't capable of pulling off some of the more sophisticated tasks such as geographic load balancing and rule-based policies, either, but considering the very low costs, they deliver all that one should expect, and maybe a little more.