Thank you Didier, I had to strongly synchronize my app using Java options (locka, synchrnized objects, and so on...).
I think it is quite unbelievable that a huge giant like BigTable is so weak in concurrency issues... Perhaps my approach is geared from my experience in relational DBs, but I'm quite puzzeld... Anyway, thank you for your hints! Bye CRI On Dec 26, 9:14 am, Didier Durand <[email protected]> wrote: > Hi, > > I guess that you should read the "Background" parag > ofhttp://code.google.com/appengine/articles/scaling/contention.htmlto > 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 <[email protected]> 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
