I'll have to double check but my understanding is that prefetch kicks off a lookup and returns what is local. I think it's a way to parallelize things a bit. So the null would mean that it just hasn't shown up yet if I'm correct.
On Jan 12, 2010, at 9:45 AM, Sergio Bossa wrote: > Thanks Chris, Steve. > > That did the trick: I reproduced the problem and verified the fix > (reported previously in this thread). > > Anyways, there are still a few questions: in particular, does > prefetch() return null because the mapping doesn't actually exist in > the master server? > > This means that, if the fix only works because it delays the moment it > loads the mapping, the original code is indeed correct: then the > problem may be the *async write toward the master*, taking too long. > > To verify that, let me check with sync writes enabled .... come back > in a few minutes. > > On Tue, Jan 12, 2010 at 6:26 PM, Chris Dennis > <[email protected]> wrote: >> Sergio, >> >> I just put a Thread.sleep in the __tc_applicator_put method of >> ConcurrentDistributedMapDso that way you can delay the application of new >> puts, and make the race to perform an incoherent read of a locally >> non-existent mapping much wider. Its not something you can do permanently, >> but it can be used to at least verify the fix. >> >> Chris >> >> On Jan 12, 2010, at 12:21 PM, Steve Harris wrote: >> >>> chris used a trick in another test to slow down broadcast applys to >>> exacerbate an issue. Maybe he can tell you how he did that? >>> >>> On Jan 12, 2010, at 9:09 AM, Sergio Bossa wrote: >>> >>>> Okay, now I'm *sure* that ConcurrentDistributedMapDso#prefetch() >>>> actually returns null even if the mapping is existent (confirmed by >>>> logging sessions). >>>> Too bad, while that always happen in my application, I'm unable to >>>> reproduce the same case through a system test. >>>> >>>> I'll keep trying and keep you posted. >>>> >>>> On Tue, Jan 12, 2010 at 4:20 PM, Steve Harris <[email protected]> >>>> wrote: >>>>> >>>>> Could someone create a test for the bug too. >>>>> >>>>> On Jan 12, 2010, at 7:15 AM, Jason Voegele wrote: >>>>> >>>>>> On Tue, 2010-01-12 at 15:40 +0100, Sergio Bossa wrote: >>>>>>> >>>>>>> Do you want me to file a jira issue and commit the fix (I have commit >>>>>>> access to the forge), or do you want to fix it by yourself? >>>>>>> Moreover, is it possible to issue a new module release as soon as the >>>>>>> bug is fixed (which is why I'm adding Jason to the thread)? >>>>>> >>>>>> I'll be happy to cut a new release when you and Chris think it is >>>>>> ready. >>>>>> Just post a message with the request when ready. >>>>>> >>>>>> -- >>>>>> Jason Voegele >>>>>> Remembering is for those who have forgotten. >>>>>> -- Chinese proverb >>>>>> >>>>>> _______________________________________________ >>>>>> tc-dev mailing list >>>>>> [email protected] >>>>>> http://lists.terracotta.org/mailman/listinfo/tc-dev >>>>> >>>>> >>>> >>>> >>>> >>>> -- >>>> Sergio Bossa >>>> Software Passionate and Open Source Enthusiast. >>>> URL: http://www.linkedin.com/in/sergiob >>> >> >> > > > > -- > Sergio Bossa > Software Passionate and Open Source Enthusiast. > URL: http://www.linkedin.com/in/sergiob _______________________________________________ tc-dev mailing list [email protected] http://lists.terracotta.org/mailman/listinfo/tc-dev
