You could also go with the sharded counter strategy. The more shards you have, the less the chance that you'll have a collision, and you'd use @Version for optimistic locking on each shard.
On Mar 9, 7:18 am, legendlink <gregc...@gmail.com> wrote: > Thanks for the reply. > > If memcache is used, how do I implement it so that the counter would > always be updated and not be deleted? > > On Mar 6, 4:35 am, "Ikai L (Google)" <ika...@google.com> wrote: > > > Have you looked into Memcache's INCR? > > >http://code.google.com/appengine/docs/java/javadoc/com/google/appengi..., > > long) > > > This'll do it atomically, but you run the risk of it being volatile, > > so you'll have to account for that in your client code. > > > On Tue, Mar 2, 2010 at 11:40 PM, legendlink <gregc...@gmail.com> wrote: > > > hi, i wanted to have a sequence generator that increments by x value > > > everytime it generates a value. if i would create the sequence > > > generator by using the datastore, it is likely that data contention > > > would occurr if there is high access times. > > > > i have looked into the sample code of max ross in the google code > > > repository (SequenceExamplesJDO.java) and think this is limited to > > > increment by 1 only and not increment by x value. > > > > if sharding technique is used, my concern is that i might not get the > > > right sequence. > > > > what is the best/elegant way of doing sequence generator that > > > increments x value? > > > > -- > > > 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 > > > athttp://groups.google.com/group/google-appengine-java?hl=en. > > > -- > > Ikai Lan > > Developer Programs Engineer, Google App > > Enginehttp://googleappengine.blogspot.com|http://twitter.com/app_engine -- 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.
