XML messages and XML Schema are not very common in the Apache Kafka and Event Streaming world! Why? Many people call XML legacy. It is complex, verbose, and often associated with the ugly WS-* Hell (SOAP, WSDL, etc). On the other side, every company older than five years uses XML. It is well understood, provides a good structure, and is human- and machine-readable.

This post does not want to start another flame war between XML and other technologies such as JSON (which also provides JSON Schema now), Avro, or Protobuf. Instead, I will walk you through the three main approaches to integrate between Kafka and XML messages as there is still a vast demand for implementing this integration today (often for integrating legacy applications and middleware).

XML and XML Schema

Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The World Wide Web Consortium’s XML 1.0 Specification of 1998 and several other related specifications — all of them free open standards — define XML.

The design goals of XML emphasize simplicity, generality, and usability across the Internet. It is a textual data format with strong support via Unicode for different human languages. Although the design of XML focuses on documents, the language is widely used for the representation of arbitrary data structures such as those used in web services. Several schema systems exist to aid in defining XML-based languages, while programmers have developed many application programming interfaces (APIs) to assist the processing of XML data.

#open source #big data #integration #xml #json #kafka #middleware #event streaming #kafka connect platform #kafka connectors