So, it's been a while since my last post. I've been traveling visiting customers and partners (and took a little Thanksgiving holiday vacation too...). But, while visiting some folks on the east coast, I had an opportunity to learn about a number of really inspired Web services solutions underway. In fact, a number of them are in support of some critical government functions. I'd like to tell you about some of them but... well... I can't. ;-) But, I CAN tell you this: anybody that even suggests that Web services cannot support serious, mission-critical applications could not be more mistaken.

Anyways, I also heard about a number of interesting iControl applications. One was particularly interesting AND shows how iControl can provide a more flexible and adaptive environment for managing a wide variety of application traffic.

In this example, the customer has a federated search application that gathers information from a variety of old and new systems. Because some of the older systems run batch processes as part of an asynchronous request, it is hard to know the relative utilization levels of each redundant server. Some of these batch processes are very lengthy in terms of completion and others are very process intensive. But, since the connections are not handled in a standard way, it's difficult to make intelligent traffic management decisions as there is virtually no information from which to make the decision.

So, the (very intelligent) developers at this customer thought about it and realized that they could, with a little coding, determine anticipated completion time of a batch process. And, they could tell other details like how many concurrent processes run on the server. With this information, they were then able to build an iControl app that takes this constantly changing status and pass a request to BIG-IP to alter the Dynamic Ratio LB mode for how BIG-IP directs traffic to each server for optimal performance.

If a server has many long-lived processes running, it tells BIG-IP to decrement it's priority in the load balancing scheme. When status changes to a reduced workload, it instructs BIG-IP to return to a more static mode to begin receiving more new requests.

The bottom line is that they can now balance traffic intelligently that they couldn't before. The result is more predictable availability, enhanced application performance, and fewer support calls. Pretty cool stuff.

Have you done something similar? Do you have an even more interesting use for iControl or iRules? I'd like to hear about it. Send me an email at