Understanding data collectors
At least one data collector exists for each aspect of system performance.
For example, the PRCS collector collects only data that is associated with processes, while the FMNT collector focuses on data that is related to file systems.
Here is how the data collectors work:
At the beginning of every interval, an interval record is created for each category of data to be collected. An interval record is what data collectors use to store the data that is collected during the interval.
Each category of data has its own uniquely named record (the process collector stores its data in the PRRE record, the file-system collector uses the FMRE record, and so on).
As soon as the interval begins, each collector starts collecting its data by using the OE data gatherer.
From then on, each collector periodically collects data. A preset rate called a sample rate (also called a collector rate) determines how often a collector collects data. Each collector has its own sample rate associated with it.
A sample rate is simply a multiple of the base cycle, which is preset by the BMC AMI Ops Monitor for USS product at one second. Therefore, if a collector’s sample rate is 15, the collector gathers its data once every 15 seconds.
- The data collectors deposit their data in their records. This data is permanent and updated continuously throughout the interval. At the end of the interval, the record is written to the historical database, where it can be referenced by the TIME command.
Steps in requesting a view
When you request a view from the
BMC AMI Ops Monitor for USS
product, the following actions occur:
- BMC AMI Ops Monitor for USS checks the view’s definition to see what data the view requires. For example, the PSOVERZ view definition tells BMC AMI Ops Monitor for USS to get data from the PRRE, P1RE, P3RE, and MTRE interval records (which contain data that is gathered by the PRCS and WADR collectors).
- BMC AMI Ops Monitor for USS accesses the current interval records (for example, PRRE, P1RE, P3RE, and MTRE).
- BMC AMI Ops Monitor for USS formats the data according to the specifications in the view definition. This formatted data is now considered a complete view.
- The view is displayed on your monitor.