Ah, that's interesting. From what I could tell via appstats during my requests, in my 1-N relationship the L2 cache was only caching the individual objects, not the entire collection. So, two accesses of the same collection in two subsequent requests would require a round trip to the memcache for each element of the collection. This is what caused my problem as the latency on the memcache lookups was between 10-30ms for each element, which gets you to some pretty awful request times even when dealing with only ~100 total elements.
>From my perspective it seems like a mistake for Google to be using JDO in all the main Java documentation. It doesn't seem like it will well work for many reasonable scenarios, although DataNucleus 2.x seems to have a lot of these issues sorted out. On Wed, Apr 7, 2010 at 3:41 PM, datanucleus <andy_jeffer...@yahoo.com>wrote: > > I think if I were to do it all over again I'd either embed the items > right > > in the order, or not use JDO at all and try to do some more manual > caching > > and batch loading. A lot of time was spent learning how JDO was loading > the > > items collection and then trying to get JDO to cache that collection. It > > might be possible, but I couldn't figure it out. > > DataNucleus 2.x has L2 caching enabled by default, and caches > relations (1-1, 1-N, M-N). Sadly GAE/J still doesn't support that > version and no sign of when it will either (in fact DN 2.1 is in > progress so they'll be even further behind soon). Can't remember how > much of L2 caching was complete in DN 1.1 since it was so long ago. > > -- > 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-j...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > > -- 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-j...@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.
