ZXTM - How it Works

Virtual Servers, Pools and Monitors


ZXTM Processing Flowchart (click to view)

ZXTM processes incoming traffic using a 'Virtual Server' object. This object performs a number of operations on the incoming request, such as SSL decryption security policy enforcement, request buffering (TCP offload) and rate shaping.

Once the request has been accepted, it is passed on to an appropriate 'Pool' object which load-balances the request to a suitable back-end server. The Pool can apply session persistence logic, encrypt traffic and limit bandwidth (if required). If appropriate, the pool also retries the request if the back-end fails to return a response.

Once the pool receives a response, it is handed back to the Virtual Server, which streams the response data back to the remote client. While doing so, the virtual server will buffer the response (freeing up the server rapidly), apply HTTP compression, monitor conformance to desired service levels, and bandwidth-limit the response data if required.

ZXTM's content cache can be used to completely bypass the back-end server.

Separately, a series of Monitors continually probe the back-end servers to verify they are working correctly. If they fail, the pools are informed and they will stop sending traffic to those servers.

TrafficScript™ rules

ZXTM includes many more features than just load-balancing, including rate shaping, bandwidth limiting, service level verification, content caching, HTTP compression and intelligent request routing.

One key strength of ZXTM is its programmability using TrafficScript rules. With TrafficScript, you can inspect any aspect of a request or response, completely rewrite the request or response if necessary, and control how exactly ZXTM should handle that specific connection. No longer is it a case of 'one-configuration-for-all-traffic' - you can define precisely which features of ZXTM should be used for each request. It's just as if you could configure your traffic manager individually for every request it sees.

Java™ Extensions

Additional traffic management functionality and control can be implemented using ZXTM Java™ Extensions.  Java Extensions can inspect, process and manipulate traffic in the same way as TrafficScript, and can draw on the enormous range of proven Java class libraries and modules to implement very sophisticated functionality.

Java Extensions are the key to the extensible nature of ZXTM, allowing almost any functionality to be implemented in the ZXTM Application Delivery platform.

The ZXTM KnowledgeHub

The ZXTM KnowledgeHub (http://knowledgehub.zeus.com/) contains a large number of examples illustrating the use of TrafficScript and Java Extensions:

Other useful resources include:

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