No problem! You could setup a task queue with 1/s rate and only 1 concurrent task.
When this task gets finished, dispatch the same task again. Sleeping a thread will probably consume unnecessary resources considering that the memcache update should only take a few miliseconds (5~10). On Mon, Jun 27, 2011 at 3:13 PM, [email protected] < [email protected]> wrote: > Sounds promising... Should say that I didn't know about the backend service > so far. I'm starting with GAE, but with a non trivial problem, instead of a > hello world :-) > > Now I just need to be able to update my timers in a second by second > fashion (there are situations where I need to restart them). As far as I > could see, Thread.sleep( 1000 ) should not be a problem... > > Thanks for the advice Bruno! > > > On Mon, Jun 27, 2011 at 1:35 PM, Bruno Fuster <[email protected]>wrote: > >> Right... >> >> I'm not sure but you could use the increment method from MemcacheService >> to atomically update this value each second from a single machine (backends) >> and read that from your dynamic instances constantly using ajax. >> >> >> http://code.google.com/appengine/docs/java/javadoc/com/google/appengine/api/memcache/MemcacheService.html#increment(java.lang.Object, >> long) >> >> >> >> On Mon, Jun 27, 2011 at 1:08 PM, [email protected] < >> [email protected]> wrote: >> >>> I thought on this, but I think this works fine only if I have just one >>> running copy of my application. If I have two or more (because the workload >>> can be high), they can be out of sync regarding their local clocks. Thus, >>> requests that arrive at approximately the same time at the different >>> instances, can get a different value to the "second" variable... >>> >>> >>> >>> On Mon, Jun 27, 2011 at 12:58 PM, Bruno Fuster <[email protected]>wrote: >>> >>>> You could just put this countdown date into your cache (or even a static >>>> property if it won't change) and calculate the seconds easily using >>>> jodatime >>>> >>>> int seconds = Seconds.secondsBetween(new DateTime(), >>>> cache.get(countdownDate)).getSeconds(); >>>> >>>> After that, use javascript intervals to recalculate the countdown while >>>> the user is at your page instead of consuming some services on your >>>> back-end. >>>> >>>> >>>> >>>> >>>> On Mon, Jun 27, 2011 at 12:48 PM, [email protected] < >>>> [email protected]> wrote: >>>> >>>>> Is it possible to implement a global count down timer in GAE/J? I would >>>>> like an unique timer to be shared among all the application instances. The >>>>> precision of the timer is seconds. >>>>> >>>>> Any idea? >>>>> >>>>> -- >>>>> 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 >>>>> [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-java?hl=en. >>>>> >>>> >>>> >>>> >>>> -- >>>> Bruno Fuster >>>> >>>> -- >>>> 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 >>>> [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-java?hl=en. >>>> >>> >>> -- >>> 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 >>> [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-java?hl=en. >>> >> >> >> >> -- >> Bruno Fuster >> >> -- >> 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 >> [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-java?hl=en. >> > > -- > 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 > [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-java?hl=en. > -- Bruno Fuster -- 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 [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-java?hl=en.
