Subject:Execution Time Variation for node Author:Dhruva Nagalla Date:07 Feb 2006 10:54 AM
Hi,
I am trying to evaluate the Stylus Studio 2006 on Winxp servicepack2 and j2sdk1.4.2_09
The odd behavior I noticed is when the profiler is ran on same set of xsl and xml files its giving different execution times each time for a particular node.
Any possible reason for this kind of behavior?
We are really in a hurry to buy a XSLT profiling product.
Subject:Execution Time Variation for node Author:(Deleted User) Date:07 Feb 2006 11:35 AM
Hi, Dhruva. A number of factors can contribute to time differences from one processing run to the next. Java garbage collection, for example, isn't a scheduled task -- Java does this when it thinks it's appropriate, which can be in the middle of XSLT processing. Also, initial runs will typically take longer than subsequent runs, so consider looking at the times over a number of runs.
Can you tell us a few things to help us better understand your issue?
- What engine are you using to process the XSLT?
- How much does the total time vary from one run to the next?
- How many runs did you use to gather your benchmark data?
Subject:Execution Time Variation for node Author:Dhruva Nagalla Date:07 Feb 2006 12:04 PM
I am using Saxon 8.6.1
The difference is around .03 to .07 secs for node (which takes an average of .25 secs)
Regarding your other question, what is the best count of runs we should use to gather data?
I basically checked for an average of two runs
Subject:Execution Time Variation for node Author:(Deleted User) Date:07 Feb 2006 12:36 PM
Well, to get a meaningful sample, I'd consider looping the transformation and running it 100 or so times. At your run rate, this shouldn't be too time-consuming and might provide you with more meaningful numbers for comparison.
As I mentioned previously, the first run can often take longer than subsequent runs (allowing for the engine startup time and initialization), so coupling the statistics from that run with those from just one other isn't going to be especially telling.
Subject:Execution Time Variation for node Author:Dhruva Nagalla Date:08 Feb 2006 12:41 PM
I was wondering how the time column(call tree)for a node is showing microseconds, because JDK 1.4 only allows timings by millisecond.
Is that something manipulated by the profiler.