Hi Jef, please read the topic.
On Mon, Jun 11, 2012 at 5:46 AM, Jeff Schnitzer <[email protected]> wrote: > ConcurentModifcationException happens whenever you have transaction > collisions. You will often have transaction collisions if you modify > the same piece of data from multiple tasks. > > There are two possible situations here: > > 1) "It happens" - sometimes transactions collide. The solution is > that you should always make transactions idempotent and you should > always retry them. If you're using Objectify4, doing an > ofy.transact(new Work() { ... }) will do the retries for you. > > 2) You may need to rethink the way data flows in your app. If you > have a bunch of tasks trying to modify the same piece of data, you're > going to get a lot of collisions and collisions slow things down. > Figure out how you can serialize the transactions or combine them. > > Jeff > > On Sun, Jun 10, 2012 at 5:10 PM, Michael Hermus > <[email protected]> wrote: > > As an expirement, I replaced my use of the Objectify transaction with the > > normal low level datastore API transaction; the problem appears to have > gone > > away. There is really no need to use the Objecty wrapper, since there > are no > > actual Entities involved. If the issue comes back up subsequent to this > > change, I will post an update. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To view this discussion on the web visit > > https://groups.google.com/d/msg/google-appengine/-/oNr1a1W0shwJ. > > > > 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. > > -- Geert Audenaert Next-generation communication at http://rogerthatmessenger.com Email: [email protected] GSM: +32 474 20 15 41 Phone: +32 9 324 25 64 Fax: +32 9 324 25 65 MOBICAGE NV Antwerpsesteenweg 19 9080 Lochristi Belgium Scan to connect with me on Rogerthat Messenger. <https://rogerth.at/q/iWyvuRQk3s8J0xJEijUUfZDbPdAwl6zVjyBRhtbe_Bcw-> -- 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.
