"Uncaught exception from servlet",GAE deployment error

Question

I am getting following errors while deploying GAE application. What will be the reason for that? Stack backtrace below.

 Uncaught exception from servlet
    com.google.apphosting.runtime.HardDeadlineExceededError: This request (0000000000000000) started at 2011/11/17 04:12:01.160 UTC and was still executing at 2011/11/17 04:13:01.204 UTC.
        at com.google.appengine.runtime.Request.process-0000000000000000(Request.java)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
        at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
        at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java:56)
        at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java:1)
        at org.springframework.expression.common.TemplateAwareExpressionParser.parseExpression(TemplateAwareExpressionParser.java:66)
        at org.springframework.expression.common.TemplateAwareExpressionParser.parseExpression(TemplateAwareExpressionParser.java:56)
        at org.springframework.security.web.access.expression.ExpressionBasedFilterInvocationSecurityMetadataSource.processMap(ExpressionBasedFilterInvocationSecurityMetadataSource.java:47)
        at org.springframework.security.web.access.expression.ExpressionBasedFilterInvocationSecurityMetadataSource.<init>(ExpressionBasedFilterInvocationSecurityMetadataSource.java:29)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:33)
        at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:126)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:108)
        at org.springframework.beans.factory.support.ConstructorResolver$1.run(ConstructorResolver.java:274)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:272)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1003)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:907)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:270)
        at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:125)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1325)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1086)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
        at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:276)
        at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:197)
        at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
        at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
        at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
        at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
        at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
        at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
        at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
        at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
        at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
        at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
        at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
        at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
        at java.lang.Thread.run(Thread.java:679)

with following explanation:

This request caused a new process to be started for your application, and thus caused your application code to be loaded for the first time. This request may thus take longer and use more CPU than a typical request for your application.

A serious problem was encountered with the process that handled this request, causing it to exit. This is likely to cause a new process to be used for the next request to your application. If you see this message frequently, you may be throwing exceptions during the initialization of your application. (Error code 104)

Answer 1

Finally we sorted the issue by removing <prop key="hibernate.hbm2ddl.auto">update</prop> from the hibernate configuration,which was for automatically exporting schema DDL to the database when the SessionFactory is created.

Answer 2

You need to optimize your application for quick setup. For example:

• Uses a lightweight framework
• Reduces classes scanning (discovery) at framework setup
• Minimizes operations in ServletContextListener#contextInitialized

There is a long way for GAE application optimizations, good luck ;-)

Answer 3

As it says in the stacktrace:

HardDeadlineExceededError: This request (0000000000000000) started at 2011/11/17 04:12:01.160 UTC and was still executing at 2011/11/17 04:13:01.204 UTC.

Frontend requests to App Engine apps have 60 seconds to complete. If your request takes longer than that, it will be terminated. If you need to do a lot of work, you should do it on the Task Queue.