Hi Robert, all. Thanks, Robert. I am using Java so if anyone can shed some light on that I would be grateful. Thanks.
On Fri, Aug 27, 2010 at 2:25 AM, Robert Kluin <[email protected]>wrote: > Hi Jeff, > If you use Python it will retry 3x. > """ > The datastore uses optimistic locking and retries for transactions. If > the transaction prepared by the function cannot be committed, > run_in_transaction() calls the function again, retrying the > transaction up to 3 times. (To use a different number of retries, use > db.run_in_transaction_custom_retries().) Because the transaction > function may be called more than once for a single transaction, the > function should not have side effects, including modifications to > arguments. > """ > > http://code.google.com/appengine/docs/python/datastore/functions.html#run_in_transaction > > Not sure about Java, but they seem to keep things more-or-less consistent. > > Robert > > > > > > > > On Thu, Aug 26, 2010 at 23:41, Jeff Schwartz <[email protected]> > wrote: > > Thanks but I wasn't specifically asking about tasks but rather > transactions > > in general. I'd like to know about retries, when they are done & when > they > > aren't. I'd also like to know if there is any detailed documentation on > the > > subject. > > > > On Thu, Aug 26, 2010 at 7:37 PM, Jan Z/ Hapara <[email protected]> > > wrote: > >> > >> FWIW we've seen tasks with 23+ retries and a re-queue time of 19+hrs. > >> > >> Failure rate: depends on what you mean. Task queue can kill your > >> tasks (and requeue them) on it's own, plus there is the failure rate > >> of other GAE services. > >> > >> I'm not sure if we've got a unique use-case on our hands (I think not) > >> but we're seeing task queue failure rates of 30-90% for non-trivial > >> loads (2-5k tasks being queued up). Failure in this case means a > >> retry force by the queue manager - tasks do eventually complete, it > >> might just take a lot longer than expected. > >> > >> J > >> > >> On Aug 27, 10:58 am, Jeff <[email protected]> wrote: > >> > When a transaction fails because of contention is it automatically > >> > retried and if it is how many times will it retry? Also, can you point > >> > me to any docs that detail this & transaction failures in general? > >> > Thanks in advance. > >> > >> -- > >> 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]<google-appengine%[email protected]> > . > >> For more options, visit this group at > >> http://groups.google.com/group/google-appengine?hl=en. > >> > > > > > > > > -- > > -- > > Jeff > > > > -- > > 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]<google-appengine%[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]<google-appengine%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- -- Jeff -- 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.
