Hi John, you mentioned about persisting the memcache counts periodically into datastore. What's the best practice to do these periodical updates let's say on a situation when the traffic is very volatile? I've implemented Twig-persist into my project, so would you like to provide some additional code for the example based on the Cookbook strategy, http://code.google.com/p/twig-persist/wiki/Cookbook?
On Apr 8, 12:33 pm, John Patterson <jdpatter...@gmail.com> wrote: > You will need to read and update the object in a transaction which > will throw an exception on commit if another thread updates the same > entity. You can then refresh the object and try again. Also look > into memcache which has an atomic counter increment method that is > much faster than reading and writing to the datastore. The downside > is that the counts could be reset so you may need to periodically > store them in the datastore. > > On 8 Apr 2010, at 16:17, mscwd01 wrote: > > > Hey, > > > How do you ensure, once you have queried an object from the datastore, > > that another call to that object cannot be made? > > I basically have a bunch of objects with counters which get > > incremented during each call to that object. > > > What I need to ensure is the object doesn't get called by two threads, > > each of which increment the counter by 1 and persist the object back > > to the datastore, only for the counter to be incremented by 1 and not > > by 2. > > > Thanks > > > -- > > 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-java@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 > > . -- 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.
