[google-appengine] Re: Understanding concurrent updates

2009-10-29 Thread Stephen
On Oct 28, 1:39 am, dburns wrote: > > If those two concurrent instances both instead call: > > cached_obj=memcache.get("my_key") > > and get a result back from some earlier: > > memcache.add("my_key", my_object) > > are they susceptible to the same sort of collision if each instance doe

[google-appengine] Re: Understanding concurrent updates

2009-10-28 Thread Martin Trummer
you cannot use memcache to reliabliy increment the counter - it's just a cache and thus there's no such thing like a transaction (AFAIK) the memcache only makes sure, that a single put and get are atomic the problem arises in this case: 2 users call the same servelt, but these 2 calls will not be