Original issue
Since I changed the version from 1.6.3. to 1.6.4 I get serious performance problems working together with GWT in hosted mode.
Update 18/04/2012
The issue is reproductible also in 1.6.4.1 in dev environment. By now the best is to downgrade to 1.6.3
Update 09/07/2012
According to Kris Giesing: This is still not fixed in 1.7.0. A request that takes 330ms to process in 1.4.3, and 415ms to process in 1.6.3, takes 13740ms to process in 1.7.0. That's from timing the Java analysis code (no I/O) - almost a 40x slowdown.
Update 09/08/2012
Google acknowledged the problem in the issue 7282 of google appengine's public issue list.
This is a confirmed performance regression in 1.6.4. We (Google) are putting together a patch that contains a fix and we'll make it available as soon as we can.
Sorry for the trouble
(I'm the guy who introduced the regression)
Even after the sdk 1.6.4.1... its still to slow!
The problem is to process the request, take too long. I cant test with real data anymore, because it is too slow.
Does anyone agree?
When i try to do a batch delete (pm.deletePersistentAll(ltToBeDelete);) of 50 entity, its took me 10 seconds.
Sorry, i'll have to downgrade to the 1.6.3 SDK.. too sad :(
Yeah, something is definitely wrong: http://code.google.com/p/googleappengine/issues/detail?id=7282
Star it!