Spring Batch Hibernate configuration error when execute on SCDF

1
votes

The Problem: failed to execute spring batch job using CommandLineJobRunner, where the application defines its own data source and Hibernate configuration.

Error Message (extracted) DatabaseLookup org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup getDatabase org.springframework.jdbc.support.MetaDataAccessException: Could not get Connection for extracting meta-data; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory ... Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set

A bit about the batch job: - SCDF is run using docker-compose.yml downloaded from spring web site. - a number of properties files under /config, which are built into jar, including a Hibernate configuration file defining "hibernate.dialect=org.hibernate.dialect.MySQLDialect" - the application defines its own data source using properties below 

qre.data.driverClassName=org.mariadb.jdbc.Driver
qre.data.url=jdbc:mysql://127.0.0.1:3306/dataflow
qre.data.username=root
qre.data.password=rootpw
  • a XML configuration with place-holder definition importing these properties

  • jar file is built using spring-boot-maven-plugin, defining org.springframework.batch.core.launch.support.CommandLineJobRunner as mainClass

    org.springframework.boot spring-boot-maven-plugin a.b.c.MyCommandLineJobRunner

  • MyCommandLineJobRunner extends Spring CommandLineJobRunner and pass job name and configuration as name/value pair

    job.name=MYJOB

  • run the jar successfully on local "java -jar application.jar job.name=MYJOB"

  • register the app on SCDF and create a task. Run the task with arguments "job.name=MYJOB" The task execute failed with error above

Tried to search SCDF reference guide, but unable to find anything useful yet. Any help is apprecaited.

2
spring-cloud-dataflow

2 Answers

0
votes

I am not sure why your application tries to override the hibernate dialect property as the batch application still needs to use the SCDF's data source. You can override the hibernate dialect for the SCDF server using the property spring.jpa.properties.hibernate.dialect. You can see some of these examples here in the documentation.

0
votes

After a few changes in configuration, I believe JDBC url wasn't configured correctly. Changed it to the same value as in docker-compose.yml, 

- SPRING_DATASOURCE_URL=jdbc:mysql://mysql:3306/dataflow
- SPRING_DATASOURCE_DRIVER_CLASS_NAME=org.mariadb.jdbc.Driver

The job can then be run successfully.