LAST WEEK, WE reviewed F5 Networks' BIG-IP 5000 Application Switch, a high-end load balancer with a rich feature set that earned our highest rating of Deploy (see " Fight server overload "). This week we follow with reviews of the Radware WSD (Web Server Director) Application Switch II and the SysMaster 5000, two more worthy systems with impressive load-balancing capabilities.
As is the F5 system, the Radware unit is switch-based, with plenty of 10/100 and even Gigabit Ethernet ports. The SysMaster system is a router-based device, with only one 10/100 Ethernet port in and one out. Whereas the F5 and Radware units will handle very heavy loads and support hundreds or thousands of Web sites, the SysMaster is limited to 100Mbps of bandwidth. Nevertheless, the SysMaster is more than sufficient for most companies wanting to scale their Web sites by distributing the traffic loads across their Web server farms.
Each load balancer we tested has pluses and minuses. The F5 BIG-IP is less expensive than the Radware WSD and includes SSL (Secure Sockets Layer) acceleration and on-site installation support -- but using it to its limits as an SSL accelerator could compromise performance in other areas. The WSD includes protection against DoS (denial of service) attacks and provides excellent integration with other Radware devices, but it is relatively expensive, especially considering the extra cost of support packages. Finally, the Sysmaster costs less than the F5 or WSD system, and it includes a lot of extra functionality -- but has a relatively difficult interface and doesn't have the potential to handle as much bandwidth as the others. For an at-a-glance comparison of features of these three products, see our online chart at www.infoworld.com.
Radware WSD Application Switch II
The Radware WSD has been around for several generations, and it is stable and refined in its setup and management interface. The switch-based architecture includes 16 10/100 Ethernet ports and five GBIC (Gigabit Interface Converter) slots for Gigabit Ethernet.
Setting up the WSD is straightforward, although the difference between the browser-based configuration utility and the stand-alone application is not made overly clear. Further, the browser-based configuration utility still requires installing a fairly large application -- one cannot simply browse to the IP address of the unit to administer it, as with F5's BIG-IP. This is supposed to be possible in the next release, however.
The WSD has a default IP address, which makes configuration simple; rather than dealing with a serial terminal, you install the management application and give it the default IP address. You can then perform the basic configuration, give the unit a real IP address, then reboot it to set up VLANs (virtual LANs), Web farms, and virtual servers.
Radware's documentation is clear and well-written, with lots of screen shots to familiarize the reader with the management interface. The WSD supports a wide range of load-balancing algorithms, including round robin, least traffic, least users, local least traffic and local least users, a special algorithm for NT servers, and two custom-defined algorithms. The local least traffic and local least users algorithms send only to servers in a local group, whereas the least traffic and least users settings allow for multiple groups.