Hi, Responses inline.
On Sat, May 21, 2011 at 11:55, Joops <[email protected]> wrote: > Hi all, > > I have been working on a pet project for a few months (A note/list app > - showing an amazing lack of originality). Currently I am the only > user who uses it for real. Damn, you stole my idea... ;) > > Currently it is on Master/Slave. > > I am considering migrating over to HR, but I wanted to check a few > things. > - HR has eventual consistency, does that mean I am going to need to > be careful to make sure users don't see an inconsitent state? Possibly. But, as you seem aware, fetches by key and ancestor queries are strongly consistent. For a note-taking app this is probably not an issue, since you've probably got clearly defined entity groups... unless you allow cross-user note sharing. ;) > - As I understand it, I could avoid inconsistencies using Entity > Groups. So each user could be a root Entity, and then their notes can > be their children. Can anyone see a potential problem with this? Sounds like a logical structure. > - I saw somewhere that there may be a write rate limit on entity > groups, so if i was syncronising hundreds of notes from another > source... might that cause problems? - could anyone elaborate on their > experiance? Yes, there are write-rate limits on entity groups. Something in the low single-digits per second; I think the docs actually say 1 write per second per entity group. For a notes app, this will probably not be an issue. Presumably if you're syncing from some other source you could easily batch your writes. So instead of sending one note per request, you could send ten, twenty, or whatever you can squeeze into the request. Then you can do a batch put which will increase your write-throughput significantly. Robert > > > Thanks very much > > J. > > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > 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. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. 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.
