Here is what I know so far ... I ran the premium memcache for 18 hours yesterday and saw no cache purging. My cache size grew to 110 megs with 6000 items and the oldest cache item was 18 hours. Since the minimum cache is 1 gig, I assume there would be no purging until the size was above that.
When using shared cached, the purging is now very aggressive. Since Saturday, I have seen the oldest cache item at less than 15 mins, total cache of 10 megs and items at 500 or less. It does vary a lot but as the purging increases the cost of the application increases, as does the performance. Right now it is performing better than these numbers but with the shared cache you never know when they will purge the shit out of the cache and the application starts consuming other resources to compensate for poor memcache performance. Something clearly changed on Saturday when I saw my costs increase by 4 to 5 times as a direct result of memory cache purging. The only way you can guarantee some amount of memory cache is with the premium memcache product and the minimum size is 1 gig (roughly 10 times what I really need). This costs 12 cents per hour per gig, 2.88 per day, roughly 90 per month, over 1000 per year. It would be less painful if you could allocate smallest than 1 gig, e.g. 100 megs. So the costs would drop by a factor of 10. I will be forced to opt for the premium memcache if the shared cache continues to perform so poorly, or rewrite lots of code so I am less dependent on memcache. Both of these are direct burdens from GAE changing shared memcache. On Sunday, October 6, 2013 11:57:02 AM UTC-7, James Gilliam wrote: > > GAE has drastically changed the way MEMCACHE works; as a result my > application (ogeekcom) overall usage jumped by approximately 5 timesd. > Like a 400% increase in price. > > Specifically, they are purging shared memcache very aggressively -- > possible in an effort to force people to signup for paid memcache. > > As a result of this change, my application is using many more datastore > reads and many more instances to compensate for the poor memcache > performance. > > Like always, this was done without any announcement at all. > > If they made this change to increase make applications cost more to run, > it is illegal. > > There is no problem with them offering a premium service for memcache, but > it is illegal to degrade the previous service to force people into the paid > model. > > -- 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 http://groups.google.com/group/google-appengine. For more options, visit https://groups.google.com/groups/opt_out.
