2.1.1.2 : What is measured



Two categories of statistics are collected independently in each daemon:

  • Computing statistics (mapStatComputing): for each registered data type, the time taken by the corresponding processing function is measured in nanoseconds. One StatAccumulator is maintained per data type.
  • Communication statistics (mapStatCommunication): for each destination daemon, the round-trip latency of a message is measured --- from the moment a message is sent to the moment its MESSAGE_CONFIRMATION is received. One StatAccumulator is maintained per (destination daemon, data type) pair.


Each StatAccumulator stores the following raw values: number of events, minimum, maximum, sum (for average computation), a fixed-size histogram with configurable bounds, and counters for events falling outside the histogram bounds.