Hi, I guess that you should read the "Background" parag of http://code.google.com/appengine/articles/scaling/contention.html to see what's happening to your app and then find out a way to rearchitect it in order to avoid touching same data at same time from different transactions
Don't have enough details about your appl but maybe the recipe in following articles may help: http://code.google.com/appengine/articles/sharding_counters.html regards didier On Dec 20, 8:42 pm, cghersi <cristiano.ghe...@gmail.com> wrote: > Hi all, > I'm very new with GoogleAppEngine, and I cannot yet understand how to > deal with Transactions and concurrency. > I've got a servlet called by a queue task where I need to manipulate > several kind of objects. > I'm not able to use the Transactions, as I'm updating several objects > not belonging to the same entity group. > I'm facing a "org.datanucleus.exceptions.NucleusDataStoreException: > Concurrent Modification" problem when trying to close my > PersistenceManager object at the end of the doPost() method of the > servlet. > > Is there a known pattern to face with this problem? > > Thank you very much. > Bye > cghersi -- 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.
