Hi Jeff and Michael, Yes, I am looking for a way to ensure that multiple servers don't create the same URLInfo object at the same time.
As Michael said: If you use a transaction to retrieve the entity by key (the URL) and then create one if it doesn't exist, only one entity should be successfully created in the event of a collision. Therefore, *even if you create two different versions with different unique ids,* only one should survive. My question is do we really need to care about the lost Id (as only one entity is going to survive) in the case of collision? And can we have code snippet for allocating and assigning id to the URLInfo in the transaction that guarantees that there shall be only one instance of a URL in the datastore and the Ids of all the URLs are unique and non empty? Thanks for your patience. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/9LXWEKXdndQJ. 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?hl=en.
