Spring Cloud Data Flow is built upon several Spring projects, but ultimately the dataflow-server is a Spring Boot app, so the logging techniques that apply to any Spring Boot application are applicable here as well.
While troubleshooting, following are the two primary areas where enabling the DEBUG logs could be useful.
Spring Cloud Data Flow builds upon Spring Cloud Deployer SPI and the platform specific dataflow-server uses the respective SPI implementations. Specifically, if we were to troubleshoot deployment specific issues; such as the network errors, it’d be useful to enable the DEBUG logs at the underlying deployer and the libraries used by it.
For instance, if you’d like to enable DEBUG logs for the kubernetes-deployer, you’d be starting the server with following environment variable set.
LOGGING_LEVEL_ORG_SPRINGFRAMEWORK_CLOUD_DEPLOYER_SPI_KUBERNETES=DEBUG
=== Application Logs
The streaming applications in Spring Cloud Data Flow are Spring Boot applications and they can be independently setup with logging configurations.
For instance, if you’d have to troubleshoot the header and payload specifics that are being passed
around source, processor and sink channels, you’d be deploying the stream with the following
options.
dataflow:>stream create foo --definition "http --logging.level.org.springframework.integration=DEBUG | transform --logging.level.org.springframework.integration=DEBUG | log --logging.level.org.springframework.integration=DEBUG" --deploy(where, org.springframework.integration is the global package for everything Spring Integration related,
which is responsible for messaging channels)
These properties can also be specified via deployment properties when deploying the stream.
dataflow:>stream deploy foo --properties "app.*.logging.level.org.springframework.integration=DEBUG"