It took a few days for the ticket to get answered, but yesterday did get confirmation from Heroku that this was a problem, with Amazon EC2 causing the pain. See this:
http://getsatisfaction.com/heroku/topics/sporadic_errors_with_memcache_addon I have the same symptoms they mention, though for my app it's not sporadic, it's a state. The only way I can seem to shake it is by opening the rails console and doing Rails.cache.clear, and things go back to normal until problem kicks back up again. I'd rate this problem a 9.5 out of 10 for my app. What makes things particularly difficult for me is input comes in from outside sources and sits in memcache. In this case, what a radio station is currently playing, and it should stay there until the next time until new data comes in via the API. I suppose it's fair to say that data should be placed in the DB, which is fine. I can do that, and then do a Rails.cache.fetch from there. Any miss would mean another AR query instead of a nil. That's still a problem though, because a lot of supplementary data gets queried with the song title, artwork, photos, products and more. So all those cache misses will have a recognizable negative impact. On Tue, Oct 5, 2010 at 9:13 AM, John Norman <[email protected]> wrote: > Brandon: Regretably, I'm cheating and am using the Dalli gem without the > guidance of Heroku. :-( I couldn't get memcached-northscale to compile on my > Mac. Whatever. > > In any case: > > >> Rails.cache.write "foo", "bar" > => true > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > >> Rails.cache.read "foo" > => "bar" > > > > On Mon, Oct 4, 2010 at 3:53 PM, Brandon Casci <[email protected]>wrote: > >> Yep :) >> >> >> On Mon, Oct 4, 2010 at 4:48 PM, Teng Siong Ong <[email protected]>wrote: >> >>> are you sure that you are using the supported memcache gem? >>> http://docs.heroku.com/memcache >>> >>> On Mon, Oct 4, 2010 at 3:43 PM, Brandon Casci <[email protected]>wrote: >>> >>>> It's crazy making. >>>> >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => 1 >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => 1 >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >> Rails.cache.read "mykey" >>>> => nil >>>> >>>> >>>> On Sat, Oct 2, 2010 at 7:58 PM, Brandon Casci >>>> <[email protected]>wrote: >>>> >>>>> Hello >>>>> >>>>> I'm new to Heroku, so I'm not sure if this is a problem, or normal >>>>> behavior. >>>>> >>>>> I'm seeing a inconsistent memcache reads. Reading a key will sometimes >>>>> alternate between nil and the value placed in memcache. Other times the >>>>> value just seems to vanish, though that could be a sign that memcache is >>>>> full, though I can't find a way to tell if it's full. >>>>> >>>>> What do es everyone think might be happening? >>>>> >>>>> >>>>> >>>>> -- >>>>> ========================================= >>>>> Brandon Casci >>>>> Loudcaster >>>>> http://loudcaster.com >>>>> ========================================= >>>>> >>>> >>>> >>>> >>>> -- >>>> ========================================= >>>> Brandon Casci >>>> Loudcaster >>>> http://loudcaster.com >>>> ========================================= >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Heroku" group. >>>> To post to this group, send email to [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]<heroku%[email protected]> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/heroku?hl=en. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Heroku" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]<heroku%[email protected]> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/heroku?hl=en. >>> >> >> >> >> -- >> ========================================= >> Brandon Casci >> Loudcaster >> http://loudcaster.com >> ========================================= >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Heroku" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]<heroku%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/heroku?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Heroku" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<heroku%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/heroku?hl=en. > -- ========================================= Brandon Casci Loudcaster http://loudcaster.com ========================================= -- You received this message because you are subscribed to the Google Groups "Heroku" 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/heroku?hl=en.
