Java错误导致Openfire崩溃

Question

I am running a openfire based chat system in my server, but do get lot crashes related to the openfire java environment, i already increased the java VM memory to the 512MB but still it crashes when the server load exceeds,

i dont have many users only 20,30 at one time with a very powerful 8 core cpu, with 32 GB memory

i am running openfire 3.71. I have to restart the whole server, since restarting the openfire doenst fix the problem at all.

error i get in java is

java.lang.ExceptionInInitializerError
    at org.jivesoftware.admin.LoginLimitManager.getInstance(LoginLimitManager.java:48)
    at org.jivesoftware.openfire.admin.login_jsp._jspService(login_jsp.java:143)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:530)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1216)
    at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:39)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1187)
    at org.jivesoftware.util.LocaleFilter.doFilter(LocaleFilter.java:74)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1187)
    at org.jivesoftware.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:50)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1187)
    at org.jivesoftware.admin.PluginFilter.doFilter(PluginFilter.java:78)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1187)
    at org.jivesoftware.admin.AuthCheckFilter.doFilter(AuthCheckFilter.java:164)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1187)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:425)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:494)
    at org.eclipse.jetty.server.session.SessionHandler.handle(SessionHandler.java:182)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:933)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:362)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:867)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
    at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:245)
    at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:113)
    at org.eclipse.jetty.server.Server.handle(Server.java:334)
    at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:559)
    at org.eclipse.jetty.server.HttpConnection$RequestHandler.content(HttpConnection.java:1007)
    at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:747)
    at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:209)
    at org.eclipse.jetty.server.HttpConnection.handle(HttpConnection.java:406)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:462)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:436)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at org.jivesoftware.util.TaskEngine.scheduleAtFixedRate(TaskEngine.java:228)
    at org.jivesoftware.admin.LoginLimitManager.(LoginLimitManager.java:83)
    at org.jivesoftware.admin.LoginLimitManager.(LoginLimitManager.java:33)
    at org.jivesoftware.admin.LoginLimitManager$LoginLimitManagerContainer.(LoginLimitManager.java:39)
    ... 36 more 

Answer 1

This error does not seem to be directly related to memory shortage - usually memory errors in Java are OutOfMemoryError errors or refer to limited space for the permanent generation and such.

NullPointerException exceptions, on the other hand, are almost certainly programming errors in the executed code. Since in your case this seems to happen under load, I can take a few shots in the dark:

• There is some finite resource, such as a thread pool or an event queue, that is being exhausted and the code that uses it does not check for that condition.

• There is a race condition, where some part of the code hits uninitialized structures that are normally being initialized by another thread under lighter load.

• There is some time out that is being reached, returning null that is then not handled properly.

Please note that the amount of memory available to the VM can affect the timing of various operations, due to the effect of the garbage collector running more or less frequently. You can use a profiler, such as VisualVM , to tell whether your application is starved for memory or not.