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dynamic_window_udf

README.md

DynamicWindowUDF

Usage example

Files in this directory represent DynamicWindowUDF usage in bundle with the Kapacitor SideloadNode

Properties

@dynamicWindowUDF()
    .periodField('period')
    .periodTimeUnit('m')
    .defaultPeriod(default_period)
    .staticEvery(30s)
    .fillPeriod()
    .emitTimeout(10s)
    
// alternative configuration
@dynamicWindowUDF()
    .staticPeriod(60s)
    .everyField('every')
    .everyTimeUnit('m')
    .defaultEvery(default_every)
    .emitTimeout(10s)
  • periodField –- period field name
  • periodTimeUnit –- period values time unit to interpret them correctly: ns – nanoseconds, u/mcs/us – microseconds, ms – milliseconds, s – seconds, m – minutes, h – hours, d – days, w – weeks
  • defaultPeriod –- period default value
  • staticPeriod -- sets period constant value, cannot be changed with incoming points (Kapacitor WindowNode's period property analogue); conflicts with three previous properties
  • everyField –- every field name
  • everyTimeUnit –- every values time unit, similarly to periodTimeUnit
  • defaultEvery -– every default value
  • staticEvery -- sets every constant value, cannot be changed with incoming points (Kapacitor WindowNode's every property analogue); conflicts with three previous properties
  • emitTimeout -– UDF accumulates several points before processing. emitTimeout property defines timeout between two sequential processing moments
  • fillPeriod –- optional property. Defines if UDF should wait until the first window is fully filled (Kapacitor WindowNode's fillPeriod property analogue)

How to run this example?

docker-compose

Just run the following in the current directory:

$ docker-compose up

Now you can use kapacitor commands right from your host system. For example, you can run dynamic_window.tick and watch the results:

$ kapacitor define dynamic_window_task -tick dynamic_window.tick
$ kapacitor enable dynamic_window_task
$ kapacitor watch dynamic_window_task

After that you will able to see points coming from UDF.

To remove intermediate build container, call:

$ docker image prune --filter "label=stage=builder" --filter "label=project=dynamic_window_udf_example" --force

Explanation

This example uses number of Docker containers:

  • kapacitor-udf -- container with UDF. Uses Docker image built from Dockerfile.
  • collectd -- metrics producer. Sends them to InfluxDB. In theory, can be replaced.
  • indluxdb -- InfluxDB container. Parses Graphite data format coming from collectd. Provides metrics for Kapacitor.
  • kapacitor -- Kapacitor container. Subscribes to InfluxDB to receive metrics, processes them with TICK scripts, communicates with UDF.