What is being returned by get_multi? None or empty dictionary? Is a
namespace being specified?
Here's some test code that is working for me when deployed. What might you
be doing differently from this?
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
from google.appengine.ext import db
from google.appengine.api import memcache
class MyThing(db.Model):
name = db.StringProperty()
def __str__(self):
return "MyThing: %s" % self.name
class MemcacheTest(webapp.RequestHandler):
def get(self):
stats = memcache.get_stats()
println(self, "<b>Cache Hits:%s</b><br>" % stats['hits'])
println(self, "<b>Cache Misses:%s</b><br><br>" % stats['misses'])
memcache.set("data", "My data")
data = memcache.get("data")
println(self, "Set 'data' -> 'My data'. Get 'data' -> " + data)
key_range = range(1000)
mapping = { }
for i in key_range:
mapping["key%d" % i] = "value %d" % i
memcache.set_multi(mapping)
println(self, "Set %d values using set_multi" % len(mapping))
cached_mapping = memcache.get_multi(mapping.keys())
println(self, "Retrieved %d values using get_multi" %
len(cached_mapping))
namespace = "synccache"
println(self, "Testing namespaces with namespace '%s'" % namespace)
memcache.set_multi(mapping, namespace=namespace)
println(self, "Set %d values using set_multi in namespace '%s'" % (
len(mapping), namespace ))
cached_mapping = memcache.get_multi(mapping.keys(), namespace=namespace)
println(self, "Retrieved %d values using get_multi in namespace '%s'" %
( len(cached_mapping), namespace ))
println(self, "Testing objects")
obj_map = {}
for i in key_range:
thing = MyThing(name="thing %d" % i)
obj_map[thing.name] = thing
namespace = "things"
println(self, "Testing namespaces with namespace '%s'" % namespace)
memcache.set_multi(obj_map, namespace=namespace)
println(self, "Set %d values using set_multi in namespace '%s'" % (
len(mapping), namespace ))
cached_mapping = memcache.get_multi(obj_map.keys(), namespace=namespace)
println(self, "Retrieved %d values using get_multi in namespace '%s'" %
( len(cached_mapping), namespace ))
for key in cached_mapping:
println(self, str(obj_map[key]))
def println(handler, string):
handler.response.out.write(string + "<br/>")
application = webapp.WSGIApplication([ ('/cachetest', MemcacheTest),
], debug=True)
def main():
run_wsgi_app(application)
if __name__ == "__main__":
main()
On Thu, Dec 3, 2009 at 11:09 AM, naan <[email protected]> wrote:
> I'm using memcache.set_multi() / add_multi() for caching DataStore
> data. Code is something like following:
>
>
> users = User.all().query(....).fetch(...)
>
> mapping = {}
> for u in users:
> mapping[str(u.key())] = u
>
> memcache.set_multi(mapping, namespace='synccache')
>
>
> It seems that set_multi/add_multi returns correct value and there's no
> error logs, error messages, nor exception. However, I can't retrieve
> them with memcache.get_multi().
>
> Thanks,
> Kazuho
>
> On Dec 3, 10:46 am, "Ikai L (Google)" <[email protected]> wrote:
> > We've just tried this and it seems to work for us. What are you storing
> in
> > Memcache? How are you generating the keys?
> >
> > On Thu, Dec 3, 2009 at 10:31 AM, Ikai L (Google) <[email protected]>
> wrote:
> >
> >
> >
> > > Is there an error message when you try to store data? Do you see any
> > > information in the logs?
> >
> > > On Wed, Dec 2, 2009 at 5:49 PM, naan <[email protected]> wrote:
> >
> > >> My app id is echofonsync and the issue remains. I can get a result
> > >> from memcache.get_stats() now, but can not store new data. Thanks.
> >
> > >> On Dec 2, 5:05 pm, "Ikai L (Google)" <[email protected]> wrote:
> > >> > Is this issue still occurring for you? If so, let me know your
> > >> application
> > >> > ID.
> >
> > >> > Michael, let me know if this is causing you problems in production.
> I
> > >> can
> > >> > attempt to migrate your application to a different pool, but this is
> not
> > >> > something I'd advise if you're running in production and things are
> > >> working
> > >> > fine.
> >
> > >> > On Wed, Dec 2, 2009 at 4:26 PM, naan <[email protected]> wrote:
> > >> > > Hi,
> >
> > >> > > This happens for me too. I can't store any data into memcache.
> Also, I
> > >> > > can't get any results with memcache.get_stats(). The function
> returns
> > >> > > None.
> >
> > >> > > On Dec 2, 1:45 pm, Michael <[email protected]> wrote:
> > >> > > > The problem with consistency is: the same key maps to the
> different
> > >> > > > values (when I'm hitting another memcached server), so randomly
> I'm
> > >> > > > getting old value from memcache and it produces weird effects on
> my
> > >> > > > application (like new message appearing, though they were marked
> as
> > >> > > > read).
> >
> > >> > > > Is it going to be fixed soon?
> >
> > >> > > > On Dec 2, 11:33 pm, Michael <[email protected]> wrote:
> >
> > >> > > > > At the time of the first post it was going for about 10
> minutes.
> >
> > >> > > > > It's still happening.
> >
> > >> > > --
> >
> > >> > > 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]>
> <google-appengine%[email protected]<google-appengine%[email protected]>
> >
> > >> <google-appengine%[email protected]<google-appengine%[email protected]>
> <google-appengine%[email protected]<google-appengine%[email protected]>
> >
> >
> > >> > > .
> > >> > > For more options, visit this group at
> > >> > >http://groups.google.com/group/google-appengine?hl=en.
> >
> > >> > --
> > >> > Ikai Lan
> > >> > Developer Programs Engineer, Google App Engine
> >
> > >> --
> >
> > >> 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]>
> <google-appengine%[email protected]<google-appengine%[email protected]>
> >
> > >> .
> > >> For more options, visit this group at
> > >>http://groups.google.com/group/google-appengine?hl=en.
> >
> > > --
> > > Ikai Lan
> > > Developer Programs Engineer, Google App Engine
> >
> > --
> > Ikai Lan
> > Developer Programs Engineer, Google App Engine
>
> --
>
> You received this message because you are subscribed to the Google Groups
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>
>
>
--
Ikai Lan
Developer Programs Engineer, Google App Engine
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