at the last night i had strange problem on one of production servers. all of tomcat executors threads were stopped on creation task instance for long time (minutes!). there are example of stacktrace. also i found problem like my there https://youtrack.jetbrains.com/issue/TW-38477

gistfile1.java

Java HotSpot(TM) 64-Bit Server VM (25.31-b07 mixed mode):

"thread-request-handler-2046-main" #2046 daemon prio=5 os_prio=0 tid=0x00007f09501af800 nid=0x2eb5 runnable [0x00007f094e8e8000]
   java.lang.Thread.State: RUNNABLE
        at java.lang.Class.getDeclaredConstructors0(Native Method)
        at java.lang.Class.privateGetDeclaredConstructors(Class.java:2663)
        at java.lang.Class.getConstructor0(Class.java:3067)
        at java.lang.Class.newInstance(Class.java:408)
        at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:403)
        at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:394)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.reflect.MethodAccessorGenerator.generate(MethodAccessorGenerator.java:393)
        at sun.reflect.MethodAccessorGenerator.generateSerializationConstructor(MethodAccessorGenerator.java:112)
        at sun.reflect.ReflectionFactory.newConstructorForSerialization(ReflectionFactory.java:340)
        at sun.reflect.GeneratedMethodAccessor73.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:483)
        at org.springframework.objenesis.instantiator.sun.SunReflectionFactoryHelper.newConstructorForSerialization(SunReflectionFactoryHelper.java:45)
        at org.springframework.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.<init>(SunReflectionFactoryInstantiator.java:38)
        at org.springframework.objenesis.strategy.StdInstantiatorStrategy.newInstantiatorOf(StdInstantiatorStrategy.java:58)
        at org.springframework.objenesis.ObjenesisBase.getInstantiatorOf(ObjenesisBase.java:91)
        at org.springframework.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:73)
        at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:57)
        at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:202)
        at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:109)
        at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.createProxy(AbstractAutoProxyCreator.java:447)
        at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:333)
        at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:293)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:422)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1579)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:322)
        at ru.laximo.wsoem.ws.services.RequestDispatcher$$EnhancerBySpringCGLIB$$cd14773d.getCommandTask(<generated>)
        at ru.laximo.wsoem.ws.services.RequestDispatcher.dispatch(RequestDispatcher.java:62)
        at ru.laximo.wsoem.ws.webcatalog.CatalogImpl.QueryData(CatalogImpl.java:72)

hmmm... one of possible reason can be starting this application with debugging option.