June 30, 2008 | Comments: (0)
Battle of the bare-bones balancers: Barracuda Load Balancer vs. Kemp Load Master
A load balancer for less than $2K? Barracuda Networks offers two models by that description, and Logan Harbaugh tested the posher one, the $1,999 Load Balancer 340. At the same time, he tested the $2,499 Kemp Load Master 1500, likewise a bare-bones load balancer in terms of features but a step up in manageability, thanks to easy drop-down configurations for features such as cookie persistence and health checking. Here are Logan's Bottom Line summaries. Click the links to read the full reviews. For a closer look at products in this space, including other reviews, see "Test Center guide: Load balancers and Web accelerators."
Barracuda Load Balancer 340 Version 2.1.033
Good 7.6
Bottom Line: The Barracuda Load Balancer is a good choice for any organization looking for a low-cost way to move from a single Web server to a Web farm. It has a good basic feature set, including cookie persistence, SSL offloading, and intrusion prevention capabilities. It's not as sophisticated -- or as expensive -- as some competing products.
Kemp Load Master 1500 Version 4.1-33
Good 7.7
Bottom Line: Although initial setup is a bit of a pain, the wide variety of preset options in the Kemp Load Master make configuring persistence or sophisticated health checks easier than usual. The GUI is clear and easy to navigate, and drop-down menus handle functions that require creating scripts or custom rules in other products. The Load Master goes a step beyond the Barracuda at a slightly higher price.
Posted by Doug Dineley on June 30, 2008 09:00 AM
June 30, 2008 | Comments: (0)
Load balancers and Web accelerators compared
Today's Test Center guide to load balancers and Web application accelerators by Logan Harbaugh pulls together all of his reviews in the space over the past two years, and zeros in on the key differences among the products. This chart provides an at-a-glance comparison. To get all the juicy stuff you'll have to read his guide.
At bottom, the essential differences amount to the type of platform used (classic Intel appliance or proprietary switch hardware) and whether the system boosts application performance through compression, multiplexing, and other optimizations. The appliance vendors are in the minority, with Barracuda and Kemp Technologies value leaders at the low end and Zeus Technology a nice balance of features and price in the middle of the pack. The only appliance battling it out with switches at the top end, the Juniper DX, has exited the market.
| Product family | Number ports (1) | Health checking | SSL accel. | App accel. | App firewall | Network firewall | DoS protection | Geo load balancing |
| Load balancers | ||||||||
| Array Networks TMX | 2 to 6 | Y | Y | Some | Y | Y | Y | N |
| Barracuda Load Balancer | 2 to 14 | Y | Y | N | Y | Y | Y | N |
| Cisco Catalyst 6500 CSM | 48 to 516 | Y | Y | N | N | Y | Y | Y |
| Citrix NetScaler | 2 to 8 | Y | Y | Y | Y | N | Y | Y |
| Coyote Point Equalizer | 24 | Y | Y | Some | N | N | Y | Y |
| Web accelerators | ||||||||
| F5 Networks BIG-IP | 12 to 24 | Y | Y | Y | Y | N | Y | Y |
| Foundry ServerIron | 4 to 112 | Y | Y | Y | Y | N | Y | Y |
| Juniper Networks DX (2) | 2 to 4 | Y | Y | Y | N | N | Y | Y |
| Kemp Load Master | 2 to 8 | Y | Y | N | N | N | Y | N |
| Zeus ZXTM | 2 to 4 | Y | Y | N | N | N | Y | Y |
Posted by Doug Dineley on June 30, 2008 03:00 AM
April 05, 2007 | Comments: (0)
Judging from what I saw while testing Juniper's DX3680 load balancer, it's clear that these devices have come a long way from their humble beginnings. In its simplest form, a load balancer is a device that sends TCP/IP requests to more than one host, creating a cluster of servers that all present the same Web site. In fact, basic load balancing can be accomplished by adding multiple IP addresses to a host entry in the domain name service (DNS) system. However, doing this creates a blind round-robin system that will send the next request to the next IP address, whether that IP address actually has a working server on it or not and regardless of whether or not that server is the best server to handle the next request.
Most advances in load balancing technology are oriented toward ensuring that requests go to a server in the group best able to handle a request. Various algorithms decide which server gets the next request -- the least loaded server or fastest responding server, for example. You can also use proprietary algorithms and even agents running on each server to provide more granular and accurate information on how heavily loaded each server might be.
The process of determining whether servers are available has also grown more complex and precise, from the basic TCP/IP PING to check to see if the server has a responsive network connection to detailed checks that ensure that a particular service -- whether it's the HTTP daemon or a back-end SQL server -- are running and returning a proper response to a query.
As the basic capabilities expand and develop to a more useful level, load-balancer companies strive to differentiate themselves in other ways. From the early systems that were built on PCs with two Ethernet cards, load balancers have evolved to include up to 24 switched Ethernet ports and custom ASICs running routing rules at Gigabit wire-speed. Other systems add protection for Web servers and other types of application servers, guarding against buffer overflows, denial of service and other hacker attacks. Still others add the ability to route incoming traffic to specialized clusters of Web servers depending on the needs of the customer, so that e-commerce requests go to one cluster while video viewing is done on another.
A recent trend is to add Web acceleration technologies, including HTTP compression, caching, and consolidation of TCP/IP requests from hundreds to a few. Many products offer a basic level of load balancing functionality and allow the customer to add additional features via add-on software modules. F5, for instance, offers functionality similar to the Juniper system I recently reviewed. On the other hand, Zeus offers basic functionality at a lower price, as does the Coyote Point system -- I'll have a review of that in the coming weeks.
Posted by Logan Harbaugh on April 5, 2007 03:30 PM