If the updates are that important, just use a transaction since it effectively does what Didier describes.
Ikai Lan Developer Programs Engineer, Google App Engine Blog: http://googleappengine.blogspot.com Twitter: http://twitter.com/app_engine Reddit: http://www.reddit.com/r/appengine On Sun, Apr 3, 2011 at 5:10 AM, Peter Backx <peter.ba...@gmail.com> wrote: > I have an application that accesses a user entity. This entity also > contains a number of user specific settings that the user can update. Some > of those settings are updated by different servlets in parallel (for > instance uploading a profile picture to the blobstore) > > I'm having some serious issues keeping everything in sync. If I'm not > careful, I can easily overwrite updates that have been done in another > thread. > > I have the feeling this is a recurring issue for many GAE application, so > I'm looking for some best practices of how to deal with it. > > In the relational world, often a "version" column is added. Before updating > a row, the version number in the database is compared to the one in memory. > I suppose I can implement something like that on GAE too, but I was > wondering whether there are better/other options available in the NoSQL > world. > > > Regards, > Peter > > -- > 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 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-java@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.
