Thanks for confirming that this workaround applies to you. Given your responses, I think it safe to assume you both are affected by the aforementioned issue relating to *memcache.Client().cas()*. This *should not* affect other *memcache* methods so namespace setting should work as expected there.
I've filed an external issue on the App Engine public issue tracker <https://code.google.com/p/googleappengine/issues/detail?id=13556> so please *star* said issue if this affects you. Status updates will be posted there. On Monday, February 13, 2017 at 1:46:55 PM UTC-5, Carlos wrote: > > Good morning! Indeed, I use namespaces too, and explicitly setting the > namespace now did make it function again. > > I was about to proceed with refactoring to move away from cas() and > instead use incr(), since I may have over-engineered my race condition > need. But incr() also has namespace as a possible parameter. Any advice > on whether we should be explicitly setting namespace for both functions? > Or which function is better to rely on right now? > > P.S. Your code above has a small error: "for_case" should be "for_cas" > in case anyone will see this and cut and paste code. > > > On Monday, February 13, 2017 at 12:07:58 PM UTC-6, Nicholas (Google Cloud > Support) wrote: >> >> Thanks for the quick response. I will also await feedback from Carlos >> about this workaround as well. >> >> For the time being, I would suggest setting it explicitly for calls to >> *memcache.Client().cas()* to workaround this known issue and use >> memcache to your advantage. Know that we are aware of this issue and >> working towards its root cause. The aforementioned suggestion is the >> recommended workaround. >> >> On Monday, February 13, 2017 at 12:53:57 PM UTC-5, >> [email protected] wrote: >>> >>> I do use namespaces. Indeed, I tried to set it explicitally as you said >>> and it worked! >>> >>> So will the issue be resolved? Should I set the namespace explicitally >>> on my code just in case? >>> >>> Em segunda-feira, 13 de fevereiro de 2017 15:38:25 UTC-2, Nicholas >>> (Google Cloud Support) escreveu: >>>> >>>> I appreciate the extra troubleshooting. We've noticed an internal issue >>>> with memcache that may be related but require additional information to >>>> confirm. >>>> >>>> Are you using namespaces? If so, can you try setting the namespace in >>>> each method call explicitly? >>>> >>>> from google.appengine.api import memcache >>>> ns = "simple-namespace" >>>> memclient = memcache.Client() >>>> memclient.add("key", "A", namespace=ns) >>>> val = memclient.get("key", for_case=True, namespace=ns) >>>> result = memclient.cas("key", "B", namespace=ns) >>>> print result >>>> >>>> The purpose is to test the above instead of using: >>>> from google.appengine.api import namespace_manager >>>> namespace_manager.set_namespace(ns) >>>> >>>> I look forward to your feedback while I attempt a few more tests of my >>>> own. >>>> >>>> On Sunday, February 12, 2017 at 12:16:37 PM UTC-5, Carlos wrote: >>>>> >>>>> For what it's worth, I have an application where the "client.cas(key, >>>>> counter+1)" which has worked for years, and it practically a direct copy >>>>> of >>>>> Guido's code on the page below, is suddenly failing in the past few days. >>>>> >>>>> >>>>> >>>>> http://neopythonic.blogspot.com/2011/08/compare-and-set-in-memcache.html >>>>> >>>>> I've debugged the code extensively. It isn't that complex. But >>>>> something certainly changed on App Engine. >>>>> I've tried variations of setting the initial value. >>>>> I've tried cas_reset(). >>>>> I've tried flushing the cache just before the request. >>>>> "client.cas(key, counter+1)" is simply returning False every time >>>>> during the while True loop, eventually timing out after 30 seconds. >>>>> >>>>> >>>>> On Friday, February 10, 2017 at 1:43:22 PM UTC-6, Nicholas (Google >>>>> Cloud Support) wrote: >>>>>> >>>>>> Hey adriano_brasileiro, >>>>>> >>>>>> I was not able to reproduce the results you describe. This might >>>>>> require additional investigation which is better suited to the App >>>>>> Engine >>>>>> public issue tracker. I recommend that you file an issue there and >>>>>> posting >>>>>> a link to that issue here so that others may follow. >>>>>> >>>>>> When doing so, please include the following: >>>>>> >>>>>> - Timestamps for when you first and last noticed this issue >>>>>> occurring >>>>>> - Does it happen only when reaching a certain load? >>>>>> - Are there any other modules contending with this memcache? >>>>>> >>>>>> Also, I'd suggest using the *memcache.Client().add()* rather than >>>>>> the static *memcache.add()*. Lastly, the code you provide suggests >>>>>> that *memcache.Client().get()* returns a dict but it in fact returns >>>>>> the value of a key >>>>>> <https://cloud.google.com/appengine/docs/python/refdocs/google.appengine.api.memcache#google.appengine.api.memcache.Client.get> >>>>>> >>>>>> or *None*. >>>>>> >>>>>> I look forward to seeing you issue report. >>>>>> >>>>>> On Thursday, February 9, 2017 at 11:45:16 AM UTC-5, >>>>>> [email protected] wrote: >>>>>>> >>>>>>> I have an application in which I use the memcache to avoid race >>>>>>> conditions by retrieving keys using get(..., for_cas=True) and saving >>>>>>> using >>>>>>> cas. However, ever since yesterday 18:00 (GMT-02) cas is always >>>>>>> returning >>>>>>> False for me. Even a code as simple as this: >>>>>>> >>>>>>> memcache.add('key', 'A') >>>>>>> memclient = memcache.Client() >>>>>>> dict = memclient.get('key', for_cas=True) >>>>>>> result = memclient.cas('key', 'B') >>>>>>> >>>>>>> print result >>>>>>> >>>>>>> always returns False on a clean memcache. I have tried to run this >>>>>>> code in different applications and result is always False. If i change >>>>>>> the >>>>>>> code to use traditional get() and set(), result returns True. I havent >>>>>>> done >>>>>>> a deploy in three days, so the code haven't changed as the problem >>>>>>> started >>>>>>> to appear. Did something change in the sdk? >>>>>>> >>>>>> -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. 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