Hi Cristian, If I am correct (and I could be wrong), you want to update more than one entity group in the datastore by performing a set of sequential writes to the datastore. You may then want to read from the datastore. The writes and subsequent read are to be delayed so that the datastore write/read will take into account the already-written data.
If I am right in my interpretation of what you ask, memcache is not a guaranteed data store, in that data can be deleted from it by the GAE framework at any time. I personally create queued tasks to perform sequential writes to the datastore to the same entity group. I set the interval between successive writes to be long enough for the HRD to cope correctly. Queued tasks do not get deleted, and act as my delayed datastore write queue. Does this help you? Ian On Sep 28, 5:27 pm, "nicanor.babula" <nicanor.bab...@gmail.com> wrote: > Hi, > > I just moved my app to HRD and I am trying to use the memcache to overcome > the eventual consistency problem.. When it comes to get-by-id queries the > solution is very simple. The problem appears when I insert an entity and I > want to appear in the results of more complex queries. > Because using entity groups is not the answer in certain situations I had to > use some sort of foreign keys.. > So far I thought of a system that gets an unique id from the query based on > its FilterPredicates (eg: "MEMCACHE_PHONE_NUMBERS_contactId_12345") and then > uses that to update or read the entities from there. I would build this > system by doing my own implementation of the DatastoreService interface and > attach the memcache management on the various put/delete/get methods. > I don't want to reinvent the wheel. Is there anything already done that I > could use? > > If anybody has any suggestions feel free to enlighten me ;) > > Thanks, > Cristian. -- 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.
