thanks for your detailed answer. however, I think I won't be able to track the miss rate, since I am not keeping information which key/value pair's I am putting in memcache (since this would require to keep the list of keys again in memcache). Instead, I would like to fetch the data using the newly introduced grabTail function.
On 10 Feb., 00:34, "Ikai L (Google)" <ika...@google.com> wrote: > You really aren't going to get a useful answer to this question without > doing some testing yourself. There are several factors that can influence > this: > > - How many items are you putting into Memcache? > - How large are the items? > - Are you forcing the old items out via LRU? > > Other applications with even only minor deviations in numbers from yours > will see significantly different results simply due to different usage > patterns. > > I like the way you're approaching the problem - non-critical data that is > regularly flushed. This is the way we'd like to encourage developers to > think about how to scale their applications: differentiating between what is > critical, non-critical, what can be done synchronously versus what can be > done asynchronously. I'd toy with the cron jobs and track a miss rate as a > function of the length of the cron job interval. There's probably a stable > balance between acceptable miss rate and minimizing datastore updates you > can achieve that may very well change with time as you change the data being > saved or as your application's usage patterns shift. > > > > > > On Sun, Feb 7, 2010 at 4:34 AM, a.maza <andr.m...@gmail.com> wrote: > > Hello, > > > I am keeping non-critical data (which is updated quite often) in > > memcache. I would like to use a cronjob to fetch the data in frequent > > intervalls from memcache in order to persist it to the datastore. > > > Thus, I would be interested if anyone has any experiences with the > > average expiration time of entities that are kept in memcache (and > > there quite frequentally accessed) - 5min? 10min? > > > Thanks and regards, > > andr > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine for Java" group. > > To post to this group, send email to > > google-appengine-j...@googlegroups.com. > > To unsubscribe from this group, send email to > > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bÂunsubscr...@googlegroups.com> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-appengine-java?hl=en. > > -- > Ikai Lan > Developer Programs Engineer, Google App > Enginehttp://googleappengine.blogspot.com|http://twitter.com/app_engine- > Zitierten Text ausblenden - > > - Zitierten Text anzeigen - -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
