Kafka-aggregator¶
A Kafka aggregator based on the Faust Python Stream Processing library.
This site provides documentation for the kafka-aggregator installation, configuration, user and development guides, and API reference.
Before installing kafka-aggregator, you might want to use the docker-compose set up as a way to run it locally, in this case jump straight to the Configuration and User guide sessions.
Overview¶
kafka-aggregator uses Faust’s windowing feature to aggregate Kafka streams.
kafka-aggregator implements a Faust agent (stream processor) that adds messages from a source topic into a Faust table. The table is configured as a tumbling window with a size and an expiration time. Every time a window expires, a callback function is called to aggregate the messages allocated to that window. The size of the window controls the frequency of the aggregated stream.
kafka-aggregator uses faust-avro to add Avro serialization and Schema Registry support to Faust.
Summary statistics¶
kafka-aggregator uses the Python statistics module to compute summary statistics for each numerical field in the source topic.
mean() |
Arithmetic mean (“average”) of data. |
median() |
Median (middle value) of data. |
min() |
Minimum value of data. |
max() |
Maximum value of data. |
stdev() |
Sample standard deviation of data. |
q1() |
First quartile of the data. |
q3() |
Third quartile of the data. |
Scalability¶
As a kafka application, it is easy to scale kafka-aggregator horizontally by increasing the number of partitions for the source topics and by running more workers.
To help to define the number of workers in a given environment, kafka-aggregator comes with an example module. Using the kafka-aggregator example module, you can initialize a number of source topics in kafka, control the number of fields in each topic, and produce messages for those topics at a given frequency. It is a good way to start running kafka-aggregator and to understand how it scales in a particular environment.
Installation¶
Configuration¶
User guide¶
Development guide¶
API¶
Project information¶
The GitHub repository for kafka-aggregator
is https://github.com/lsst-sqre/kafka-aggregator
See the LICENSE file for licensing information.