Robert - the limit should be: - 10 active asynchronous RPCs. Technically, since the synchronous API just makes an async call and blocks, I suppose this translates to 10 concurrent RPCs per request.
- 5 concurrent transaction jobs per datastore instance per request. We are working on various ways to increase this limit, such as parallel transactions to multiple datastore instances. Is my explanation confusing? To answer the question about read latency - yes, the read latency should be the same. However, get by key is done inside a transaction unless you set "eventually consistent queries" to true. The reason it needs to be done inside a transaction is because we need to be sure the data you are reading is the freshest data. Fresh = data written that passes milestone A: http://code.google.com/appengine/articles/transaction_isolation.html 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 Sat, Jun 25, 2011 at 6:48 AM, Branko Vukelic <[email protected]> wrote: > On Fri, Jun 24, 2011 at 11:39 PM, Casey Dwyer <[email protected]> > wrote: > > IIRC, in one of the I/O talks ("More 9s Please" I believe), they said > that > > read latency is about the same and write latency is high in HRD. Did I > hear > > that incorrectly? > > That's exactly correct. > > http://www.youtube.com/watch?v=xO015C3R6dw&feature=player_detailpage#t=795s > > Just below that, though, the error rate is supposedly much lower for > HRD compared to MS. That's what's meant by "more 9s". > > -- > Branko Vukelić > [email protected] > > Lead Developer > Herd Hound (tm) - Travel that doesn't bite > www.herdhound.com > > -- > 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.
