Demand Technology Software
Frequently Asked Questions about NTSMF overhead and use
1. What is the overhead of running NTSMF?
2. How big are the NTSMF data files?
3. What is the format of the NTSMF data files?
Frequently Asked Questions about NTSMF overhead and use
1. What is the overhead of running NTSMF?
At typical collection intervals (we recommend at least once per minute), NTSMF overhead is well under 1% of a single processor. Chapter One of the User's Manual contains a lengthy discussion of Windows 2000 performance monitoring overhead considerations.
2. How big are the nightly NTSMF data files?
You can expect data files on the order of 2-4 MB daily. If you find that your daily .smf data files are significantly larger and that amount of data is causing unacceptable problems and delays in post-processing, there are several approaches that you can use to trim them back in size without sacrificing clarity and detail.
Review your Filter definitions.
The Filter definitions that you activate can have a major impact on the size of the .smf data files that you collect. If you are collecting an excessive number of process instance records, check your Process Filter settings. By raising the threshold for collecting data a little bit you might be able to reduce the amount of data in the file considerably.
If you find that it is the high volume of Object instances other than Process that is causing the problem, please contact Customer Support and send us a copy of your data file. We are always looking for ways to make the filtering process more intelligent.
Use the Summarization Utility
Running the Summarization Utility before you post process the .smf data file can reduce the amount of data to be processed significantly. We developed the Summarization Utility because performance management and capacity planning both work off the same source data, but at different levels of granularity. To spot performance problems and diagnose, you need detailed data. To do trend long term capacity requirements, you need summary data. Problem diagnosis normally requires recording measurement data at one minute intervals, while capacity planning trending can often work with 15, 20, 30 or 60 mminute intervals. To reconcile both needs, collect detailed data for performance management, invoke the Summarization Utility at Cycle End to reduce the size of the data file, and then transmit the summarized file for post-processing.
Output files generated by the Summarization Utility conform in all respects to the original NTSMF data file format, except that the collection interval between data records is longer. They are managed by the same hierarchical file management parameters that control the automatic archiving and deletion of the detail files. Remember that the the Summarization Utility requires the use of the Type 6 Counter Type format records to summarize the input data correctly.
3. What is the format of the NTSMF data files?
We write text files, comma delimited by default, in an open, documented format that can be easily read in almost any application. To make it easy for third party products to process our data, we developed a self-defining file format. At the start of each file, we write Configuration records and other identifying data. Then we write the dictionary records (or Format Records) which describe the contents of the file to follow. Then we write the actual data records that are collected each measurement interval. Each Object instance is written as a separate data record. Data fields have a default precision of two decimal places, but whenever more precision is required, we write the data field with an explicit decimal point.
Appendix B of the User Manual provides a complete description of the NTSMF file format.