commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Phil Steitz <phil.ste...@gmail.com>
Subject Re: [math] Multithreaded performances
Date Mon, 04 Nov 2013 22:27:07 GMT
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
> <rmannibucau@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.steitz@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.steitz@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-unsubscribe@commons.apache.org
>>>>>> For additional commands, e-mail: dev-help@commons.apache.org
>>>>>>
>>>>>>
>>>>> ---------------------------------------------------------------------
>>>>> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
>>>>> For additional commands, e-mail: dev-help@commons.apache.org
>>>>>
>>>>>
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
>>> For additional commands, e-mail: dev-help@commons.apache.org
>>>
>>>


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org


Mime
View raw message