I am seeing the same error. I believe this happens when appengine shuts down your server and then restarts the server. I have read the exception is harmless, but the slow start seems to indicate different. My startup time takes about 8 seconds.
I have created cron, that runs every minute. This seems to prevent appengine from shutting down my server very often. I probably still have the appengine shut down my server about 20+ times a day, but that is better than every request. I still have some delays on the first request after a cron restarts, but it about 3 seconds. I have also thread talking about these issues. --Jeffrey On Sat, Nov 28, 2009 at 9:00 AM, Donny <[email protected]> wrote: > I use JPA in my servlet in my app, but some times when I query data > google app engine will report some exception(following is my log from > app engine's admin log. ResultServlet is my servlet), the exception is > about: > > "com.google.appengine.repackaged.com.google.common.base.FinalizableReferenceQueue > <init> > INFO: Failed to start reference finalizer thread. Reference cleanup > will only occur when new references are created." > > this exception was discussed in this group and i found no one gave the > solution, every one said it > is not affect the performance of application. but from my log i found > it affected my performance. > > 11-28 08:37AM 44.050 survey.ResultServlet doGet: begin query data > I 11-28 08:37AM 44.703 > > com.google.appengine.repackaged.com.google.common.base.FinalizableReferenceQueue > $SystemLoader loadFinalizer: Not allowed to access system class loader > I 11-28 08:37AM 44.718 > com.google.appengine.repackaged.com.google.common.base.internal.Finalizer > getInheritableThreadLocalsField: Couldn't access > Thread.inheritableThreadLoc > I 11-28 08:37AM 44.721 > > com.google.appengine.repackaged.com.google.common.base.FinalizableReferenceQueue > <init>: Failed to start reference finalizer thread. Reference > cleanup... > I 11-28 08:37AM 45.242 survey.ResultServlet doGet: query data used > time :1188 > I 11-28 08:37AM 45.617 survey.ResultServlet doGet: render page used > time : 375 > > some times this exception will disappear, every thing go well, here is > the log: > > 11-28 08:30AM 33.170 survey.ResultServlet doGet: begin query data > I 11-28 08:30AM 33.206 survey.ResultServlet doGet: query data used > time :36 > I 11-28 08:30AM 33.212 survey.ResultServlet doGet: render page used > time : 6 > > if the exception occurs, my page will be rendered to client very slowly > (it will costs >3s), but without the exception page render is less > than 1s. And I found this exception occurs after some minute when my > application has no incoming request from client. because my > application is not in very high concurrency environment, so the > problem occurs in 50% time. > > > my code is like this: > > public class ResultServlet extends HttpServlet { > > private static final Logger log = Logger.getLogger > (ResultServlet.class.getName()); > > public void doGet(HttpServletRequest req, HttpServletResponse resp) > throws IOException, ServletException { > > List<Reply> list = null; > EntityManager em = EMF.get().createEntityManager(); > > log.info("begin query data"); > long start = System.currentTimeMillis(); > try { > > list = em.createQuery("select r from Reply as > r").getResultList(); > > log.info("query data used time :" + String.valueOf > (System.currentTimeMillis() - start)); > > start = System.currentTimeMillis(); > > ....code to deal list data. > > req.getRequestDispatcher("result.jsp").forward(req, > resp); > log.info("render page used time : " + > String.valueOf > (System.currentTimeMillis() - start)); > } finally { > em.close(); > } > } > } > > > any one can help me? > > > -- > > You received this message because you are subscribed to the Google Groups > "Google App Engine for Java" group. > To post to this group, send email to > [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-appengine-java%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > > > -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
