Even with ten-minute background tasks, your datastore RPC calls are still limited to 30 seconds. Also, if you're fetching a lot of records and sending emails based on them, you might want to break it up into smaller tasks anyway. Smaller chunks should also help you handle failures in a more graceful way; if you're trying to do this as one big job, what do you do if it fails XX% of the way through? You may not have a good way to determine what XX is, so you can resend to those XX% people or not send to the (1-XX)% of the people.
Robert On Fri, Jan 21, 2011 at 15:00, Jay <jbaker.w...@gmail.com> wrote: > Is it the fetch that is taking too long or the sending of the emails? > > I cases where the jobs really do get too big (but see Ross' note), the > typical approach is to batch up the job and use task queues. For > example, you might have your task catch DeadlineExceeded (or whatever > Exception that is) and smartly put the remaining 'emails' list on > another new task. > > On Jan 21, 12:10 pm, Ross M Karchner <rosskarch...@gmail.com> wrote: >> Cron jobs and tasks can now take up to 10 >> minuteshttp://code.google.com/p/googleappengine/wiki/SdkReleaseNotes >> >> On Fri, Jan 21, 2011 at 12:57 PM, Mayumi Liyanage < >> >> >> >> mayumi.liyan...@coldwin.com> wrote: >> > Hi, I need to iterate over all the entities in the Datastore and send >> > out emails once a day asynchronously to the actual app. >> > Usual way to do this would be to invoke a Servlet using cron which >> > would iterate over all the entities to send emails out. However, our >> > data is growing at the rapid rate and sooner or later we will have a >> > issue with 30 sec limit problem. >> > What would be the best way to do this operation using app engine >> > without worrying about 30 sec limit? >> >> > Can we do above using the Mapper API? If so how can we invoke a mapper >> > from the servlet? >> >> > Thanks. >> >> > -- >> > You received this message because you are subscribed to the Google Groups >> > "Google App Engine" group. >> > To post to this group, send email to google-appengine@googlegroups.com. >> > To unsubscribe from this group, send email to >> > google-appengine+unsubscr...@googlegroups.com<google-appengine%2bunsubscr...@googlegroups.com> >> > . >> > For more options, visit this group at >> >http://groups.google.com/group/google-appengine?hl=en. >> >> -- >> Ross M Karchnerhttp://eventgrinder.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 google-appengine@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine+unsubscr...@googlegroups.com. > 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 google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
