TomEE+ 8.0 - OperationNotSupportedException: Context is read only]

Question

Using TomEE+ 8.0 (Tomcat 9.0.12) in local Eclipse IDE and remote CentOS server. The application starts normally locally and previously started normally on the remote server. Now after changes adding a javascript WebSocket, throws a NPE on deployment to the remote server.

Any suggestions of where to start looking? This is a head scratcher.

Thank you, Ted S.

Stack Trace:

SEVERE [http-nio-9086-exec-119] sun.reflect.NativeMethodAccessorImpl.invoke Creation of the naming context failed: [javax.naming.OperationNotSupportedException: Context is read only]
SEVERE [http-nio-9086-exec-119] org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal Error merging Java EE JNDI entries in to war /o-test: Exception: null
 java.lang.NullPointerException
        at org.apache.catalina.core.NamingContextListener.createSubcontexts(NamingContextListener.java:1253)
        at org.apache.catalina.core.NamingContextListener.addEnvironment(NamingContextListener.java:785)
        at org.apache.catalina.core.NamingContextListener.processGlobalResourcesChange(NamingContextListener.java:432)
        at org.apache.catalina.core.NamingContextListener.propertyChange(NamingContextListener.java:382)
        at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
        at org.apache.catalina.deploy.NamingResourcesImpl.addEnvironment(NamingResourcesImpl.java:303)
        at org.apache.tomee.catalina.OpenEJBNamingResource.addEnvironment(OpenEJBNamingResource.java:78)
        at org.apache.tomee.catalina.TomcatJndiBuilder.mergeRef(TomcatJndiBuilder.java:403)
        at org.apache.tomee.catalina.TomcatJndiBuilder.mergeJndi(TomcatJndiBuilder.java:125)
        at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1394)
        at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130)
        at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:133)
        at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5007)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:703)
        at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:986)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
        at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1651)
        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:498)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:287)
        at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
        at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1571)
    at org.apache.catalina.manager.HTMLManagerServlet.upload(HTMLManagerServlet.java:294)
    at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:212)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:136)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:607)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.tomee.catalina.OpenEJBSecurityListener$RequestCapturer.invoke(OpenEJBSecurityListener.java:97)
    at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:685)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:668)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:770)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

Answer 1

This application served image files from a directory outside the web application root using a entry in the element for the application of tomcat's server.xml referenced here Serve static files from Tomcat

<Host name="www.example.com" appBase="webapps"
                 unpackWARs="true" autoDeploy="true" >
    <Alias>example.com</Alias>
    <Valve className="org.apache.catalina.valves.AccessLogValve" 
        directory="logs"
        prefix="oneme_access_log." suffix=".txt"
        pattern="%h %l %u %t &quot;%r&quot; %s %b" />

    <Context docBase="/var/www/html/example/media" 
            path="/myapp/media" 
            reloadable="true" />
</Host>

The problem was solved by (in this order)

1. removing the application war file
2. cleaning up unnecessary Maven dependencies that had been entered during the sprint
3. commenting out the element
4. stopping and restarting Tomcat
5. uncommenting the element
6. stopping and restarting Tomcat

Deployment was attempted after each step above. I don't have an explanation of why that worked. The application had previously deployed properly, then after a sprint, it would give the error above. I suspect that conflicting jars added by Maven had somehow disturbed Tomcat's state.

Hope sharing this helps someone.