An unexpected error occured Unable to get write lock on 'subscribe' method for: com.commafeed.backend.services.FeedSubscriptionService Go back to the previous

An unexpected error occured Unable to get write lock on 'subscribe' method for: com.commafeed.backend.services.FeedSubscriptionService Go back to the previous page or to the home page. com.commafeed.frontend.utils.exception.DisplayException: Unable to get write lock on 'subscribe' method for: com.commafeed.backend.services.FeedSubscriptionService at com.commafeed.frontend.pages.GoogleImportCallbackPage.<init>(GoogleImportCallbackPage.java:94) at sun.reflect.GeneratedConstructorAccessor187.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:525) at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:170) at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:98) at org.apache.wicket.DefaultMapperContext.newPageInstance(DefaultMapperContext.java:137) at org.apache.wicket.core.request.handler.PageProvider.resolvePageInstance(PageProvider.java:278) at org.apache.wicket.core.request.handler.PageProvider.getPageInstance(PageProvider.java:166) at org.apache.wicket.request.handler.render.PageRenderer.getPage(PageRenderer.java:78) at org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:94) at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:244) at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:165) at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:840) at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64) at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:254) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:211) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:282) at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:244) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188) at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:267) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:45) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:722) Caused by: javax.ejb.ConcurrentAccessTimeoutException: Unable to get write lock on 'subscribe' method for: com.commafeed.backend.services.FeedSubscriptionService at org.apache.openejb.core.singleton.SingletonContainer.aquireLock(SingletonContainer.java:303) at org.apache.openejb.core.singleton.SingletonContainer._invoke(SingletonContainer.java:222) at org.apache.openejb.core.singleton.SingletonContainer.invoke(SingletonContainer.java:205) at org.apache.openejb.core.ivm.EjbObjectProxyHandler.synchronizedBusinessMethod(EjbObjectProxyHandler.java:256) at org.apache.openejb.core.ivm.EjbObjectProxyHandler.businessMethod(EjbObjectProxyHandler.java:251) at org.apache.openejb.core.ivm.EjbObjectProxyHandler._invoke(EjbObjectProxyHandler.java:85) at org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:279) at com.commafeed.backend.services.FeedSubscriptionService$LocalBeanProxy.subscribe(com/commafeed/backend/services/FeedSubscriptionService.java) at com.commafeed.backend.feeds.OPMLImporter.handleOutline(OPMLImporter.java:58) at com.commafeed.backend.feeds.OPMLImporter.importOpml(OPMLImporter.java:34) at com.commafeed.frontend.pages.GoogleImportCallbackPage.<init>(GoogleImportCallbackPage.java:92) ... 37 more