Janusgraph: Janus shutdown hook cannot be disabled and logs unwatned warnings

[wojciechwojcik]

When JanusGraph close() method is called from another shutdown hook e.g. coming from spring boot application, bogus warnings are logged:

WARN [ Thread-11] o.j.g.d.StandardJanusGraph : Failed to remove shutdown hook java.lang.IllegalStateException: Shutdown in progress at java.lang.ApplicationShutdownHooks.remove(ApplicationShutdownHooks.java:82) ~[?:1.8.0_144] at java.lang.Runtime.removeShutdownHook(Runtime.java:239) ~[?:1.8.0_144] at org.janusgraph.graphdb.database.StandardJanusGraph.removeHook(StandardJanusGraph.java:259) [janusgraph-core-0.2.0.jar:?] at org.janusgraph.graphdb.database.StandardJanusGraph.close(StandardJanusGraph.java:193) [janusgraph-core-0.2.0.jar:?] at ... at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_144] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_144] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_144] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_144] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:366) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeDestroyMethods(InitDestroyAnnotationBeanPostProcessor.java:325) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeDestruction(InitDestroyAnnotationBeanPostProcessor.java:154) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DisposableBeanAdapter.destroy(DisposableBeanAdapter.java:253) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroyBean(DefaultSingletonBeanRegistry.java:578) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingleton(DefaultSingletonBeanRegistry.java:554) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingleton(DefaultListableBeanFactory.java:961) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroyBean(DefaultSingletonBeanRegistry.java:571) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingleton(DefaultSingletonBeanRegistry.java:554) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingleton(DefaultListableBeanFactory.java:961) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingletons(DefaultSingletonBeanRegistry.java:523) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.destroySingletons(FactoryBeanRegistrySupport.java:230) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingletons(DefaultListableBeanFactory.java:968) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.destroyBeans(AbstractApplicationContext.java:1032) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1008) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.support.AbstractApplicationContext$2.run(AbstractApplicationContext.java:929) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE]

Either there should be an option to disable Janus shutdown hook completely (via configuration property or Java api) or the warning should not be logged when application shutdown is in progress.

[rehevkor5]

This also makes it impossible to achieve graceful shutdown because we cannot control the order in which shutdown hooks run. Ideally, we would wait for outstanding transactions to complete, and then shutdown the graph. Instead, the graph shutdown hook runs, and outstanding transactions throw many exceptions.