IT Pro Verdict
It's expensive but the ZXTM 7400 delivers a most comprehensive range of load balancing and traffic management tools in a well specified appliance that we found relatively simple to install and use.
In the world of application traffic management Zeus Technology is one of the key players in this market and for good reason. Claimed as one of few software solutions on the market, Zeus' Extensible Traffic Manager (ZXTM) has always stood out thanks to its superb range of features. Originally only offered as a software product, Zeus made the move to appliance-based solutions around eighteen months ago and now provides a family of four platforms. In this exclusive review we take a closer look at its new flagship - the ZXTM 7400.
ZXTM offers an extensive range of features to web based applications and web sites including Layer 7 traffic management and high-performance load balancing along with extensive security measures. The appliance runs the latest ZXTM 4.1r2 software which includes a few minor improvements and fixes. The last significant release was version 4.1 which introduced Zeus' request rate shaping feature which, as its name suggests, allows you to set a limit on the number of request types allowed through the appliance. It's aimed at stopping problems such as service abuse, floods and dictionary based attacks.
One thing we've always liked about the Zeus solution is its easy installation and the 7400 is no exception. Just connect the dedicated management interface to your network, point a web browser at the default or DHCP assigned address and follow a brief, seven-step questionnaire. This takes you through assigning hostnames, entering IP addresses for the four public interfaces, providing DNS and gateway details, licensing the box and then moving on to the main web interface for general management and monitoring.
Virtual server creation is dealt with by a wizard that steps you neatly through defining the service. It really is very simple as you just choose a name for your virtual server, pick a protocol from the drop down list and add your nodes. We successfully created pools for collections of Windows servers running general web services, FTP and web mail which were then assigned to our virtual servers. The appliance functions as an application proxy and as far as our test clients were concerned it was completely transparent as we merely pointed their web browsers at its service ports to access the required service.
Using virtual servers means you can add more physical servers to a pool as and when required without taking a service offline. A drain function also allows you to safely remove back end servers as it stops new connections associating with a specific node. Once your service is up and running the appliance performs load balancing across all nodes in the pool and offers a range of schemes to choose from. You can go for a simple round-robin mode which distributes inbound requests to each node in strict rotation or modify this behaviour by applying different weightings to each node in the pool. The least connections and fastest response modes are self explanatory whilst the perceptive mode measures system responses and distributes traffic accordingly. Alternatively, you can create a priority list which determines a strict order that each node will be used in.
Rules make the ZXTM very versatile - especially as each pool can have rules for requests and responses. They use sets of conditions and actions to determine how traffic should be handled and conditions can be anything from a local or remote IP address, a cookie, remote port, HTTP header or a URL path. Actions are just as varied and range from HTTP redirects, dropping connections, adding headers or simply gathering logging information. Bandwidth restrictions can also be applied as actions and you can create multiple classes with different maximum bandwidth values.
The appliance has the ability to maintain persistent connections with a variety of methods. Source addresses can be used to ensure traffic from a specific host always goes to the same node within a pool or you can use other methods such as rules or monitored application cookies. There's much more as for each virtual server you can apply service protection classes which limit the number of requests it can handle to stop it getting overloaded. Bandwidth restrictions can be applied wholesale to specific virtual servers and service level monitoring classes used to ensure warnings are sent out if SLAs aren't being maintained. Zeus' TrafficScript tool adds another dimension to the appliance as this can be used to create sophisticated custom traffic management rules. Don't expect to get the hang of TrafficScript in a day as it is a complex tool but is ultimately very powerful.
There's no denying the ZXTM 7400 comes with a premium price tag but it is delivering an unbeatable range of features. During testing we found the appliance particularly easy to use thanks to its well designed and intuitive management interface and it is worth noting that the price does include support for an unlimited number of virtual servers.
Verdict
It's expensive but the ZXTM 7400 delivers a most comprehensive range of load balancing and traffic management tools in a well specified appliance that we found relatively simple to install and use.
2U rack chassis
Supermicro H8DAE motherboard
2 x 2.6GHz AMD Opteron 285
8GB 400MHz SDRAM
ICP Vortex GDT8114RZ Ultra320 single channel RAID controller with 128MB cache memory
2 x 73.5GB Fujitsu Ultra320 SCSI hard disks in RAID-1 array
Dual embedded Broadcom Gigabit
Intel PRO/1000 MT dual-port Gigabit PCI card
Supermicro IPMI management card
2 x 500W hot-plug power supplies
Linux kernel
Web browser management
