57. Logging

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.

57.1 Deployment Logs

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.

  1. For instance, if you’d like to enable DEBUG logs for the local-deployer, you’d be starting the server with following.

    $ java -jar <dataflow-server>.jar --logging.level.org.springframework.cloud.deployer.spi.local=DEBUG

    (where, org.springframework.cloud.deployer.spi.local is the global package for everything local-deployer related)

  2. For instance, if you’d like to enable DEBUG logs for the cloudfoundry-deployer, you’d be setting the following environment variable and upon restaging the dataflow-server, we will see more logs around request, response and the elaborate stack traces (upon failures). The cloudfoundry-deployer uses cf-java-client, so we will have to enable DEBUG logs for this library.

    $ cf set-env dataflow-server JAVA_OPTS '-Dlogging.level.cloudfoundry-client=DEBUG'
    $ cf restage dataflow-server

    (where, cloudfoundry-client is the global package for everything cf-java-client related)

  3. If there’s a need to review Reactor logs, which is used by the cf-java-client, then the following would be helpful.

    $ cf set-env dataflow-server JAVA_OPTS '-Dlogging.level.cloudfoundry-client=DEBUG -Dlogging.level.reactor.ipc.netty=DEBUG'
    $ cf restage dataflow-server

    (where, reactor.ipc.netty is the global package for everything reactor-netty related)

[Note]Note

Similar to the local-deployer and cloudfoundry-deployer options as discussed above, there are equivalent settings available for Apache YARN, Apache Mesos and Kubernetes variants, too. Check out the respective SPI implementations to find out more details about the packages to configure for logging.

57.2 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"