Waterfall analysis in SAP monitoring user action duration

[Shirai]

We are validating SAP monitoring.

We Waterfall analyzed an action with a Duration of 1.9 seconds. I was able to confirm the details of 1.9 seconds. The sum of all detailed items is longer than the Duration. Also, in other user actions, "detail item total time" < "Duration".
I understood that the sum of the detail items matches the Duration, is my understanding wrong?

[ChadTurner · Accepted solution]

@Shirai great question. Looking at your screen shot we can see that the entire duration is 1.90 seconds. and as you have highlighted, there are 8 segments that contribute to the overall 1.90 seconds, but adding them up exceeds the claimed 1.90 second duration. While this is true, we need to keep in mind that each segment is running asynchronous with each other as we can see each progress bar starts at the same time. so adding them up will give you an inaccurate duration number as they all processed during that 1.90 seconds and completed at some point during that 1.90 seconds.  the max duration in your highlighted section is 1.84 seconds, but also while they were running so was the networking requests which surpassed the 1.84 seconds with a value of 1.90 seconds, so the total duration is 1.90 seconds.  When you expand out these buckets keep in mind they don't always "add up" to the overall value since components might not wait for other components to complete prior to running, they run asynchronously. 

[Mike_L]

Just two minor changes. Other than that, good explanation 👍

They run asynchronous (the a is important 😊)

SAP doesn’t tell us when the different steps start, so we always place them as start on 0. 

[ChadTurner]

Thanks for catching that! ill update the post 🙂