I need some help: My web application has an upload file function. These files can be huge. While the file is uploading, the upload class spawns a new thread to send status updates to the client's progress bar. This works fine even for the most giant files except when we want to make a parallel deployment while uploads are happening.
08-Jul-2016 10:41:41.852 WARNING [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [WebApps##001012] is still processing a request that has yet to finish. This is very likely to create a memory leak. You can control the time allowed for requests to finish by using the unloadDelay attribute of the standard Context implementation. Stack trace of request processing thread: ... and the stack trace shows it is right in the middle of a file upload. On top of that, the threads that update the upload progress bar are firing and are being beat down by tomcat: 8-Jul-2016 10:41:42.233 INFO [http-nio-8080-exec-7] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access: this web application instance has been stopped already. Could not load [META-INF/services/javax.xml.parsers.SAXParserFactory]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access. java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [META-INF/services/javax.xml.parsers.SAXParserFactory]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access. ... And that's one of the upload progress threads. The first message mentions setting unloadDelay as a possible solution. The docs are light on the consequences of setting that value abnormally high to accommodate the largest of file uploads. What would setting it to an hour (3600000 ms) or more do? Will the next version of the webapp deploy and run for new sessions while the old one waits to idle out? What about those threads? Will they be allowed to fire while it is waiting on shutdown? I'm in the process of setting up a sandbox but if y'all have advice for me that would save me the trouble of setting the scenario up on a set of test servers, I would REALLY appreciate it.
