Kafka For Pythonistas

Matt Howlett has an introduction to Apache Kafka, designed for Python developers:

In the call to the produce method, both the key and value parameters need to be either a byte-like object (in Python 2.x this includes strings), a Unicode object, or None. In Python 3.x, strings are Unicode and will be converted to a sequence of bytes using the UTF-8 encoding. In Python 2.x, objects of type unicode will be encoded using the default encoding. Often, you will want to serialize objects of a particular type before writing them to Kafka. A common pattern for doing this is to subclass Producer and override the produce method with one that performs the required serialization.

The produce method returns immediately without waiting for confirmation that the message has been successfully produced to Kafka (or otherwise). The flush method blocks until all outstanding produce commands have completed, or the optional timeout (specified as a number of seconds) has been exceeded. You can test to see whether all produce commands have completed by checking the value returned by the flush method: if it is greater than zero, there are still produce commands that have yet to complete. Note that you should typically call flush only at application teardown, not during normal flow of execution, as it will prevent requests from being streamlined in a performant manner.

This is a fairly gentle introduction to the topic if you’re already familiar with Python and have a familiarity with message broker systems.

Related Posts

Optimizing Apache Flink

Ivan Mushketyk has a few tips for speeding up programs using Apache Flink: One more way to optimize your Flink application is to provide some information about what your user-defined functions are doing with input data. Since Flink can’t parse and understand code, you can provide crucial information that will help to build a more […]

Read More

Anomaly Detection With Kafka Streams

Ajmal Karuthakantakath shows us an application which performs fairly simple anomaly detection using Kafka Streams: The problem is in the banking loan payment domain, where customers¬†have taken a loan and they need to make monthly payments to repay the loan amount. Assume there are millions of customers in the system and all these customers need […]

Read More

Categories

June 2017
MTWTFSS
« May Jul »
 1234
567891011
12131415161718
19202122232425
2627282930