With the 7.3 release, IBM introduced historical performance data collection and the ability to view your historical data graphically with Graph History. With the recent Navigator service pack (HTTP Server Group PTF SF99722 Level 7 or later), graph history was expanded with stacked charts. Stacked charts allow you to display and compare a historical data metric over days, weeks, months, or years.
Historical data collection is off by default and you must turn it on – it is a configuration property for Collection Services. Once you start collecting historical performance data, Graph History allows you to visualize that data over days, weeks, months, or years.
Stacked charts are very easy to use. Once you are collecting historical data and display a historical summary chart, you can switch to the stacked chart view by simply clicking on the Stacked Chart view icon – which looks like two parallel lines.
The period of time over which the charts are stacked is determined by the timeframe in which the historical data is selected.
- Stack by day is used when the historical data to be displayed is less than two weeks.
- Stack by week is used when the historical data to be displayed is from two weeks up to and including two months.
- Stack by month is used when the historical data to be displayed is greater than two months and less than two years.
- Stack by year is used when the historical data to be displayed is two years or more.
A simple example will show how easy this is.
I have opened a historical summary chart for CPU Utilization (Average) over the past year. On my (uninteresting) test system, the chart looked like the one below:
You will note the double-arrow icon in the upper right corner with the “Stacked Chart View” popup text under it. When I click on this icon, the stacked chart view is opened.
Since I was looking at one year of data, the stacked chart view is displayed by month. In my example I am reviewing CPU Utilization (Average) of my IBM i partition over the past year and I can see how my usage varies from month to month.
You can easily change the metric you are reviewing and the timeframe with the context section of the graph history interface:
When you change the metric, you will see that metric in the summary view, but you can then review that metric with stacked charts.
You can find more information on the stacked charts and other enhancements to the performance tasks in the April 2017 service pack update on the PDI Changes in PTFs page. Note that graph history, and subsequently stacked charts, are only available with IBM i 7.3. If you are on 7.3, be sure to install the latest HTTP Server Group PTF for this capability. If you are not yet on 7.3, you have another reason to consider moving there (particularly if you are still on 7.1).
This blog post was edited for currency on November 3, 2020.
This blog post was originally published on IBMSystemsMag.com and is reproduced here by permission of IBM Systems Media.