Spring MVC Slow on Google App Engine for Java?

We previously tried deploying Spring-based Java web applications on Google's App Engine (GAE). And I remember abandoning it due to the time it takes to handle a loading request.

Now, I was able to get some time to create a minimal Spring MVC web application and see how it performs on GAE. Below is the result. The web.xml loads the ContextLoaderListener and DispatcherServlet. The application context is empty (i.e. no beans). The dispatcher-servlet.xml contains a <context:component-scan /> tag and a ViewResolver. It takes about 6.75 seconds for a loading request (approximately cpu_ms=3600).

6.75 seconds for a loading request is probably not much. But the 1100 cpu_ms by slim3 is sure enviable. I also found this article helpful in explaining the cause of increase in loading request time.

Here's some detailed log entries:

javax.servlet.ServletContext log: Initializing Spring root WebApplicationContext
…
org.springframework.web.context.ContextLoader initWebApplicationContext: Root WebApplicationContext:
initialization completed in 2420 ms
…
javax.servlet.ServletContext log: Initializing Spring FrameworkServlet 'dispatcher'
org.springframework.web.servlet.FrameworkServlet initServletBean: FrameworkServlet 'dispatcher': initialization started
…
org.springframework.web.servlet.FrameworkServlet initServletBean: FrameworkServlet 'dispatcher':
initialization completed in 2995 ms

Looks like the DispatcherServlet eats up some processing time. If we just use the ContextLoader, and plain-vanilla servlets, the loading request time should be tolerable.