Processor App in Spring Boot 2.2.4/Hoxton.SR1 not working in Spring Cloud Data Flow 2.4.1

Question

I am trying to develop a new application to work on SCDF 2.4.1 and Skipper 2.3.1

I took the samples from https://github.com/sabbyanandan/stream-programming-models

Answer 1

For function based stream modules to work with SCDF, you need to add the appropriate binding name properties to input and output to your application properties as described here: https://cloud.spring.io/spring-cloud-static/spring-cloud-stream/3.0.3.RELEASE/reference/html/spring-cloud-stream.html#_functional_binding_names

Essentially, this maps the functional binding endpoint names to the SCDF endpoint names, input and output. For example, if you have a Function `foo':

spring.cloud.stream.function.bindings.foo-in-0=input spring.cloud.stream.function.bindings.foo-out-0=output

.Future releases of the prepackaged stream modules will use the Functional paradigm and will provide these properties automatically.

Answer 2

I believe the problem is that the current published stream apps, http and log, use an earlier version of spring-cloud-stream, based on spring boot 2.1.x. The newer version of spring-cloud-stream that is compatible with boot 2.2.x is not backwards compatible. All apps in the stream must be on the same (or compatible) spring-cloud-stream versions. I expect if you look at the log for custom processor, you will see some conversion error.