They seem to vary pretty widely. The best way to use memcache is to only store data in there that is ALSO in the datastore. The purpose of memcache is to save save time in the event the value is there your app doesn't have to go to the datastore to get the data, but you should never have anything that only exists in memcache.
On Oct 29, 7:40 pm, Baron <[email protected]> wrote: > that's interesting Barry. I had assumed each user had their own > dedicated quota, which I guess would be wasteful. > > Has anyone done tests of the eviction rates? > > On Oct 29, 11:41 pm, Barry Hunter <[email protected]> wrote: > > > memcache is a shared system. Everybody uses from the same 'pool'*. So > > if the system as a whole is running out of memory maybe your data will > > get evicted. > > > Some have stated there is also a per user limit (perhaps 10Mb - but it > > could change). > > > As others have stated - never design that the data will be thare later > > (maybe the memcache node your data was on was restarted or crashed) - > > its a temporally cache. If you find a cached value, bonus(!), > > otherwise just generate the data like you where going to anyway. > > > * I beleive that is how Google have implemented it anyway. > > > 2009/10/29 Baron <[email protected]>: > > > > ah OK. > > > > Do you know how much memcache memory each app can use before values > > > start being evicted? > > > The quota page lists the daily rate as 10GB, but not the size. > > > > On Oct 29, 4:32 pm, ryan baldwin <[email protected]> wrote: > > >> That is incorrect. The value can be ejected from Memcache at any time. As > > >> some of the Googlers have stated in the groups, you should not design > > >> your > > >> applications to depend on a persistent cache. > > > >> - ryan. > > > >> On Wed, Oct 28, 2009 at 11:25 PM, Baron <[email protected]> wrote: > > > >> > Hello, > > > >> > If I store only a single int in my app memcache, how long can I expect > > >> > it so stay cached? > > > >> > According to the docs "Values may be evicted from the cache when a new > > >> > value is added to the cache if the cache is low on memory." > > >> > So then in the case of my single int there should be no memory > > >> > problems and the data will last indefinitely. Is that right? > > > >> > thanks --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
