Apologies, I was wrong. Roughly ~10mb of entities is the maximum. Hopefully you don't need *that* much data to be transactional.
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 Thu, Jul 21, 2011 at 10:13 AM, Ikai Lan (Google) <[email protected]>wrote: > There's no limit to the number of ops. As long as everything is in a single > entity group, it "counts" as one write. > > That being said, the more entities you write, the more indexes and data you > write, and this does impact the amount of CPU used. > > 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 Thu, Jul 21, 2011 at 11:37 AM, tempy <[email protected]> wrote: > >> I use GAE for, among other things, a synchronization backend for my >> mobile app. The mobile app is designed to stay offline for long >> periods of time and then report everything that happened while it was >> offline to the GAE backend. >> >> I "merge" this sync data into a user's data in an async task, with all >> the data being written in just one huge batch put and one huge batch >> delete, all within one transaction (a user's data is always contained >> within one entity group). >> >> So far this has been working well, according to appstats the >> transaction commit frequently takes many seconds (typically around 5) >> but just a few hundred MS in wall-clock time. What scares me a little >> is when a user has been very active, a sync can result in thousands >> (or even tens of thousands) of writes or deletes, and then the commit >> takes stomach-turning amounts of time, like in the 30 second range. >> Impressively, the wall-clock time is still under a second. >> >> My question is, is there some theoretical maximum for how many >> datastore ops can be squeezed into a single transaction within an >> async task? When asking the datastore to do a commit that takes a >> minute in "cpu-time", will it start timing out at some point? I >> haven't hit an upper ceiling yet, but if one exists I'd like to know >> about it. >> >> -- >> 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.
