"IllegalArgumentException: Name must not be null" when deploying to jboss - jboss

Question

(I already solved this problem, but posting it here to help others.)
I recently upgraded from Grails 2.4.4 to Grails 3. When deploying to JBoss EAP 6.4 (Wildfly 7), I receive the following error in the server log and the application fails to start:
09-06 20:46:18,463 ERROR [org.jboss.as.web.deployment.JBossContextConfig] (ServerService Thread Pool -- 90) JBAS018202: Error calling onStartup for servlet container initializer: org.springframework.web.SpringServletContainerInitializer: java.lang.IllegalArgumentException: Name must not be null
at org.springframework.util.Assert.notNull(Assert.java:115) [spring-core-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.util.ClassUtils.forName(ClassUtils.java:214) [spring-core-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:284) [spring-core-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.grails.transaction.ChainedTransactionManagerPostProcessor.resolveTransactionManagerClass(ChainedTransactionManagerPostProcessor.java:158) [grails-core-3.1.5.jar:3.1.5]
at org.grails.transaction.ChainedTransactionManagerPostProcessor.hasJtaOrChainedTransactionManager(ChainedTransactionManagerPostProcessor.java:143) [grails-core-3.1.5.jar:3.1.5]
at org.grails.transaction.ChainedTransactionManagerPostProcessor.postProcessBeanDefinitionRegistry(ChainedTransactionManagerPostProcessor.java:119) [grails-core-3.1.5.jar:3.1.5]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:123) [spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:678) [spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:520) [spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at grails.boot.GrailsApp.run(GrailsApp.groovy:55) [grails-core-3.1.5.jar:3.1.5]
I have two different data sources in the application, both of which are registered in JNDI.
After running through a debugger, I see that transactionManagerBeanDefinition.getBeanClassName() returns null but I am not sure why.
Why would this error be happening, and how would I solve it?

Answer 1

This link led me to the answer.
The problem seems to be caused by there being multiple datasources in my application, which causes Spring / JBoss to get confused when setting up the transaction manager.
The solution is to set transactional: false in application.yml for the second datasource. This worked perfect for me, since the second datasource is read-only anyway.
application.yml:
dataSources:
dataSource:
dialect: "..."
otherDataSource:
dialect: "..."
transactional: false <------ add this line