I am analyzing strobe report for the first time. Strobe report is more or less self descriptive and if not then compuware manual makes it easier to understand. But I still have some questions -
1. TIME DISTRIBUTION OF ACTIVITY LEVEL - As I understand from the manual whatever number is populated in the section has to be multiplied by 10 to get our acitivity level.But what does activity level means. And at what point should one be concerned ie say at particular instance activity level is 1(or 10) and that is fine, but if it is 7(or 70) then we should be alrmed. And how do we know at that particular instance what our program is doing due to which we have high activity level.
2. For DB2 query - is it fine if our query shows the total time as .48%. What is allowable "total time" for a query.
3. EXCP count - Does one I/O operation means 1 EXCP Count.
On the first few pages, STROBE tells you the rough cut of what was happening during sampling. Look at CPU % vs WAIT %. Then look at "stretch time."
Also, always be thinking in terms of what you are trying to achieve: low CPU, low wall clock time, low EXCP...etc.
I've seen people spend weeks trying to get the CPU% down by 1, when the entire job is running 18 hours because of i/o. When they fixed the i/o problem, the CPU% went UP, but the total CPU time went down.
I'm pretty sure the STROBE I/O is a singe EXCP (EXecute Channel Program). That is from the job out to the storage system. So a single COBOL read can have differing EXCPs if there are different buffers involved.