GiAPA - Performance

PERFORMANCE ANALYSIS

Having data available for all jobs every 15 seconds, the possibilities for different reports and charts are almost infinite. This report is often chosen as the first to look at the results from an analysis: “Job Performance Summary” descending by CPU time used.

Here are a few examples of results and options based on above data – we refer to the red numbers:

1. Batch job SNBRVRE consumed for hours almost an entire CPU – 715 million reads and only 1613

disk

accesses. Cause was easy to spot: Job was looping!

2. 19066 batch jobs “behaved” so well that GiAPA decided not to keep them individually for detailed

analysis – but all details are available, just in case…

3. An interactive job should never use more than one hour CPU – the user probably ran batch-type

programs! Placing the cursor on the job and hitting F6, F7 or F8 will give analysis of files accessed

(+ spot inefficient I/Os), and F9 will run call stack analysis (tell which program(s) used most

resources) F10 / F11 give further details.

4. To see graphical representation of e.g. jobs using more than ½ hour CPU, place the cursor on the

last job above the dotted line and hit F14. The chart data will contain CPU seconds used, because

the

report sequence was descending on CPU usage.

By default a bar chart is selected:

But of course the user may select between different types

As stated above, there are so many possibilities. Here is a 3D column chart showing the users causing the highest number of disk accesses.

This report shows which user programs that most often caused a HotSpot, i.e. were active when a job had used more than 6 % CPU the last 15 seconds. Optimizing the top-10 here is likely to cure 80+ % of all performance concerns … (F14 would have made the data available for graphic display.)

If you know that there was a performance drop at a given point of time, you can of course get statistics per 15-seconds data collection interval. It also shows the system ASP disk usage percent, and the names of the 6 jobs that used the most resources at each interval.