I still think that what you need is a thread-safe copy rather than a thread-safe mutate. 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 > > > > >
