Availabilty & the Performance Graphs

This is my penultimate post on the subject of Availability statistics. The earlier post on this was Accessing Availability Statistics.

If you’ve read an understood everything up to this point (then give yourself a gold star) you’ll want to know how you can access Availability data.

This information is available through the SerioClient Chapter called ‘Performance’ (click the link underneath ‘Tools’). If you open a Performance Chapter you’ll see the following graphs that you can use:

  • Availability – Item
  • Availability – System
  • Downtime – Item (Monthly)
  • Downtime – Item (Monthly User Based)
  • Downtime – Item (Weekly)
  • Downtime – Item (Weekly User Based)
  • Downtime – System
  • Downtime – System (User Based)

All of these graphs take the ingredients I’ve mentioned before – the Availability SLA, and the Incidents logged against the Item or System – and compute your downtime data for you. All you need to have is accurate Incident records.

Let’s look at these Graphs more closely.

Availability Item, Availability System

These reports express Availability as a percentage over a monthly date range, going back from the report start date a total of 6 months and in so doing allowing the trend of Availability to be discovered. For each month, and for each Item or System , Serio computes the maximum possible Availability based on your SLA in minutes (MAXh), and then computes the amount of downtime (DOWNh) . It then expresses downtime (or more accurately, Availability) as a percentage using this formulae

PCT = ((MAXh – DOWNh) / MAXh) * 100

for each Item or System. As criteria for the graph, you need to supply two items of information:

Impact – So that the calculation of DOWNh is made solely on the basis of Incidents that are related to system unavailability.

Item Type Category (for the Availability Item graph). This is so you can restrict your graph to particular classes of Item (for instance ‘Enterprise servers’).

This style of graph has an interesting side effect – it can make what would otherwise be considered poor availability look quite good.

I’ll complete this post early next week by covering the Downtime reports, and what ‘User based’ means.

In the meantime, have a peaceful weekend, if that’s your thing. Otherwise have a riotous weekend.