[NIFI-5618] NullPointerException is thrown if attempting to view details of a Provenance Event on a node that is disconnected from cluster

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.8.0
• Component/s: Core Framework
• Assignee: Mark Payne
• Reporter: Mark Payne
• Created: 20/Sep/18 19:21
• Updated: 25/Sep/18 10:29
• Resolved: 25/Sep/18 10:29

Description

I have a cluster of 2 nodes. I disconnected one of the nodes, then did a Provenance Query. This returned the results correctly. However, when I tried to view the details of the provenance event, I got an error in the UI indicating that I should check my logs. User log has the following (partial) stack trace:

2018-09-20 15:16:36,049 ERROR [NiFi Web Server-177] o.a.nifi.web.api.config.ThrowableMapper An unexpected error has occurred: java.lang.NullPointerException. Returning Internal Server Error response.
java.lang.NullPointerException: null
at org.apache.nifi.web.api.ProvenanceEventResource.getProvenanceEvent(ProvenanceEventResource.java:299)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:76)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:148)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:191)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:200)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:103)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:493)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:415)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:104)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:277)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:272)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:268)
at org.glassfish.jersey.internal.Errors.process(Errors.java:316)
at org.glassfish.jersey.internal.Errors.process(Errors.java:298)
at org.glassfish.jersey.internal.Errors.process(Errors.java:268)

 

It appears to be due to the fact that since the node is disconnected, the clusterNodeId is not provided in the REST API call. So the following block of code:

final ClusterCoordinator coordinator = getClusterCoordinator();
if (coordinator != null) {
    final NodeIdentifier nodeId = coordinator.getNodeIdentifier(clusterNodeId);
    event.setClusterNodeAddress(nodeId.getApiAddress() + ":" + nodeId.getApiPort());
}

results in calling coordinator.getNodeIdentifier(null), which returns null for the nodeId. We then call nodeId.getApiAddress(), throwing a NPE.

Issue Links

• links to: GitHub Pull Request #3027