From 0743ddd7782c01a976ae377e74f701797064854e Mon Sep 17 00:00:00 2001 From: Jakub Holy Date: Tue, 15 May 2012 16:06:02 +0200 Subject: [PATCH] initial --- README.md | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 README.md diff --git a/README.md b/README.md new file mode 100644 index 0000000..e0d03fe --- /dev/null +++ b/README.md @@ -0,0 +1,34 @@ +INTRO +Light-weight, minimalistic, low-overhead lib for collecting and publishing performance statistics in production systems. +Calls to the lib are usually injected via AOP. + +Overview: +- code calls Statistics.recordMeasurement(String metricName, long duration [, unit]) +- the measurement is added to a list of values to process and the call returns +- a background thread processes new measurement, updating aggregate values etc. +- the collected values are made available via publishers such as JmxPublisher and PeriodicalLogPublisher + +USAGE + +Statistics.recordMeasurement("myBizMethod", 60); +// => asynch. stored and updated count, avg, min, max, std.dev, ... +// Computation strategy: rolling window x all values + +STATS + +- ignore lowest and highest N values (random extreems far behind normal values) +- count avg, 10 min, 10 max, std.dev. +- running avg/dev or based on all values + +ATTRS OF INTEREST + +Count attribute The number of times this event has occurred. +ErrorCount attribute The number of times this event ended in error. +AverageTime attribute The average execution time, in the selected unit. +MaxTime attribute The maximum execution time, in the selected unit. +MinTime attribute The minimum execution time, in the selected unit. +StandardDeviation attribute The standard deviation from the mean, in the selected unit. +LastInvocation attribute The most recent date and time at which this event occurred. +Units attribute The unit of measure for max, min, average, and stddev. Valid values are seconds, milliseconds, and nanoseconds. Defaults to milliseconds if unspecified. +reset operation Reset statistics for this type of event. +