The fact that iStats give you a view of the entire device when querying any particular stat, vs. iStats provides a more flexible, scalable, picture complete (non TMM specific) mechanism for tracking information vital to your deployment, and critical when building business solutions in many cases. Hopefully the picture that is shaping up is as obvious to everyone else as it is to me. - iStats can be both read and modified by the control plane, I.E.- Any consumer of iStats (even iRules) will always get the global view (meaning, not on a per-TMM basis, but rather aggregated over all stat producers), which is extremely important in many cases where you want to look at the overall picture when referencing a stat, not a per TMM number, given that there are multiple if not many TMMs per device in most cases.- iStats do not have to be preconfigured or predefined, they can be built on the fly, effectively.- Users can create an arbitrary number of iStats (although there is a practical limit of 5,000-10,000 iStats).

In contrast, let's look at iStats in a similar way and compare the differences: They aren't amazingly flexible, and provide limited hooks into the control plane (command line, GUI, etc.) which makes them somewhat isolated from the bigger picture of your BIG-IP's configuration and existence at large. While a stats profile can be useful in many cases, it is largely used to track data plane only metrics such as connections, data rates, etc. - Cannot be modified from the control plane.- Stat values are sometimes available only on a per-TMM basis.

- Limited to a small number of statistics.

First let's look at what we know about a stats profile: IStats are similar in concept to the existing stats profile, with several important variations. IStats are user-created custom statistics, accessible from both the data plane (iRules) and the control plane (tmsh, on-box scripts, etc.). In this 2-parter we'll talk about iStats first from a higher level overview/introduction perspective, and then a bit more in-depth in part 2, talking about specific metrics that are measurable, commands available from within iRules, etc. iStats were introduced in v11, and are worth talking about, as they can dramatically change the way you are solving problems, depending on your deployment. Between sideband connections, iFiles and improvements of already existing functionality, it's hard to imagine there is more yet to discuss in v11 iRules goodness, but there is. iRules improvements and features were among the cooler things changed, in the opinion of this avid iRuler. Version 11 of BIG-IP brought with it many enhancements and new features ranging across the entire product.

Istats frequency