On 11/4/13 2:22 PM, Ted Dunning wrote: > I still think that what you need is a thread-safe copy rather than a > thread-safe mutate.
I was just thinking the same thing. Patches welcome. Phil > Even if you force every thread to do the copy, the > aggregation still still wins on complexity/correctness/performance ideas. > > > On Mon, Nov 4, 2013 at 12:58 PM, Romain Manni-Bucau > <rmannibu...@gmail.com>wrote: > >> In sirona we collect (aggregate) data each N ms and we can still use stats >> during aggregation (worse case surely) >> Le 4 nov. 2013 21:48, "Phil Steitz" <phil.ste...@gmail.com> a écrit : >> >>> On 11/4/13 12:12 PM, Romain Manni-Bucau wrote: >>>> But aggregation needs to lock so not a real solution. Lock is fine on >>> real >>>> cases but not in simple/light ones. ThreadLocal leaks...so a trade off >>>> should be found >>> Depends on the use case. If the use case is >>> >>> 0) launch a bunch of threads and let them gather stats individually >>> 1) aggregate results >>> >>> Then the static aggregate method in AggregateSummaryStatistics that >>> takes a collection as input will work with no locking required. >>> >>> Phil >>>> Le 4 nov. 2013 18:42, "Phil Steitz" <phil.ste...@gmail.com> a écrit : >>>> >>>>> On 11/4/13 8:49 AM, Romain Manni-Bucau wrote: >>>>>> Hi, >>>>>> >>>>>> ATM sirona (a java monitoring library in incubator) relies a lot on >>>>>> Summary stats object from [math3] but it needed a lock to ensure >>>>>> consistency. I know there is a synchronized version but this one >>>>>> scales less then the locked one. >>>>>> >>>>>> My question is quite simple then: will [math] add an implementation >>>>>> with thread safety guarantee and good performances? I think for >>>>>> instance to the LongAdder of Doug Lea which could be used as a good >>>>>> base. >>>>> The short answer is yes, patches welcome. >>>>> >>>>> Ted makes a good point, though; and there is already some support >>>>> for aggregation in the stats classes in [math] (i.e., you can >>>>> aggregate the results of per-thread stats by using, e.g. >>>>> AggregateSummaryStatistics#aggregate). See MATH-1016 re extending >>>>> this to more stats. >>>>> >>>>> Phil >>>>> >>>>>> Romain Manni-Bucau >>>>>> Twitter: @rmannibucau >>>>>> Blog: http://rmannibucau.wordpress.com/ >>>>>> LinkedIn: http://fr.linkedin.com/in/rmannibucau >>>>>> Github: https://github.com/rmannibucau >>>>>> >>>>>> --------------------------------------------------------------------- >>>>>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>>>>> For additional commands, e-mail: dev-h...@commons.apache.org >>>>>> >>>>>> >>>>> --------------------------------------------------------------------- >>>>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>>>> For additional commands, e-mail: dev-h...@commons.apache.org >>>>> >>>>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>> For additional commands, e-mail: dev-h...@commons.apache.org >>> >>> --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
