Useful metric opertions
The ZIMON pmcollector measures various metric counters with a frequency defined as a sensor period. It stores only the delta value of the readings between 2 points in time. In the Grafana panel editor there are five operations available for metric transformation: sum, avg, max, min and rate. The sum, avg, max and min operations allow the aggregation of several values, while the rate operation allows you to change the level of granularity of the values.
The rate operation returns the metric value per second, i.e. it divides the stored value by the number of seconds corresponding to the frequency of the sensor period. Compare two graphs below.
The metric "gpfs_fs_bytes_read" (number of bytes read) is measured by the GPFSFilesystem sensor every 10 seconds. Between 13:40:40 and 13:40:50, 20KiB were read from node scale-11 on the localFS filesystem.
The rate operation causes the value of 20KIB to be divided by the number of seconds between 13:40:40 and 13:40:50. In other words, at 13:40:50 the average gpfs_fs_bytes_read per second was 2KIB.