And there is NO transaction at all. We don't use transaction. But I am not sure if objectify uses the transaction in put.
On Thursday, December 3, 2015 at 9:59:00 PM UTC-8, Jeff Schnitzer wrote: > > You'll need to post some more code details - including the structure of > the object you are trying to change. Also you don't mention whether this is > an exception or just a log message. It's easy to accidentally create > contention with the task queue, especially if you're in a transaction and > enqueueing non-transactional tasks (which often start immediately). > > Jeff > > On Thu, Dec 3, 2015 at 6:14 PM, Yun Li <y...@thetrackr.com <javascript:>> > wrote: > >> I am using Objectify. This error happens when updating a single datastore >> entity. There is NO TRANSACTION. My working flow as follows: >> >> 1 Entity entity1 = Objectify.read(id1) >> 2 Modify entity1's property and put "update(entity1)" in a taskqueue >> 3 When task executes: Objectify.save(entity1) >> >> Then I get java.util.ConcurrentModificationException: too much >> contention on these datastore entities >> >> It's so weird because the log shows that even two requests try to update >> entity1, their execution interval could be more than 10s. I am a new GAE >> user, anybody helps me ? >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Google App Engine" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to google-appengi...@googlegroups.com <javascript:>. >> To post to this group, send email to google-a...@googlegroups.com >> <javascript:>. >> Visit this group at http://groups.google.com/group/google-appengine. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/google-appengine/52790fdf-d521-4f95-b35d-217bcbe2379c%40googlegroups.com >> >> <https://groups.google.com/d/msgid/google-appengine/52790fdf-d521-4f95-b35d-217bcbe2379c%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/d1688715-9f14-45d2-afd9-a6d826f22b51%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
