This a long time issue for java apps. And it seems GAE team doesn't care this issue. Basically, this is a gae instance scheduler defect.
Currently, only one way to avoid the slow startup problem: buy more always-on instances. On Oct 20, 12:57 pm, Casey <j.casey.one...@gmail.com> wrote: > I've been developing an application for quite some time and I always > noticed the following things while testing: > > - The first hit to the quiet server took a long time due to > application startup. Anywhere from 10-30 seconds. Sometimes I see 60 > seconds. > - Performance would be ok but it seems like a lot of extra instances > would be spun up with just a single user. That's even with safe > threading enabled. > - Of course after a few minutes of idle time the instance would spin > down and then the next request would take a long time to process while > a new instance was spooled up > > I should also mention that I'm using GWT with RPC and I'm using Spring > to manage all of my services. I do think that the use of Spring is why > my application takes so long to start up. Since the datastore EMF > handles my transactions I really only use the spring framework to > provide dependency access to singleton beans across servlets and RPC > services. But the primary reason I use Spring is for the session > scoped bean so that I can store objects in the session. I actually > don't store much in the session, just the current user id so > performance should be OK. > > During QA I was kind of OK with with the bad performance because I > attributed the delays with the spooling up of instance #1. Yesterday I > enabled the persistent instances where I pay $9 a month to have three > instances constantly powered on and waiting. That seemed to work at > first. My first hit to server where I access a JSP is pretty fast. > Login then takes awhile and then my first RPC call took forever. When > I looked at the instances it made sense. Even though there were three > instances waiting for traffic, for some reason, a single user > accessing the server caused another three instances to be spooled up > for a total of six. Again, this is just for a single user accessing > the system. > > I've since accessed appstats and inserted a bunch of logging > statements. As far as I can tell, all of my datastore requests are > <100ms. Since some RPC calls make multiple calls to the DB I see some > request times around 0.5s or 1s. I wouldn't think that such a time > would cause additional instances to be spun up. So my only guess as to > why additional instances keep getting spun up is that Spring is taking > forever to load the small configuration files. It also looks like > Spring isn't initialized until login is called. Post access to the > JSP. > > So what do I do? I've tried to optimize Spring startup as much > possible but that clearly doesn't seem to be working. Does anyone have > any suggestions or do I have to figure out how to completely ditch > Spring and use Guice for my dependency injection. If that's true, what > do I do about the session scoped bean? I found a bunch a GAE session > projects for python but so far I haven't found one for managing > session objects in java. Does anyone have any ideas? -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
