[erlang-questions] Why Beam.smp crashes when memory is over?

ERLANG <>
Thu Nov 12 10:49:50 CET 2009


5 customers (2 for my team)

Y.

Le 12 nov. 09 à 10:41, Angel Alvarez a écrit :

>
> 3 customers!!
>
>
> /Angel
>
> El Jueves, 12 de Noviembre de 2009 00:56:14 Michael McDaniel escribió:
>> On Wed, Nov 11, 2009 at 11:38:47AM +0100, Ulf Wiger wrote:
>>> Richard O'Keefe wrote:
>>>>
>>>> On Nov 11, 2009, at 11:26 AM, Ulf Wiger wrote:
>>>>
>>>>> Richard O'Keefe wrote:
>>>>>
>>>>>> I am not denying the *need* for limits.  (Anyone else remember  
>>>>>> "engines"
>>>>>> in Scheme?)  I've had enough functions in enough languages go  
>>>>>> into
>>>>>> infinite recursion that I can see the point of stopping them.
>>>>>> However, Ulf Wiger has not addressed these points:
>>>>>> - if the tagging scheme is changed (and it has in the past),
>>>>>>  memory requirements may change.
>>>>>> ...
>>>>>
>>>>> Perhaps I'm colored by having worked on systems where every
>>>>> product release was preceded with months of relatively
>>>>> thorough testing, where monitoring memory usage during
>>>>> important operating conditions was routine.
>>>>
>>>> Let's see if we can reach consensus here.
>>>
>>> I think we do agree. Hopefully the volley will clarify things
>>> to the rest of the crowd - let's go another round and see if
>>> people will start groaning. :)
>>>
>>>> What I'm saying is that you have to *KEEP* doing it,
>>>> as indeed you did ("every product release"), and that
>>>> you have to keep doing it even if YOUR code didn't
>>>> change at all.
>>>
>>> Indeed. For high-availability products, this ought to
>>> be a given. But as Erlang is also used in many other settings,
>>> I would like to add an observation - perhaps obvious to all:
>>>
>>> Erlang has some limits /today/ that programmers have to live
>>> with. In many cases, the limits are high enough that they
>>> are no cause for concern. Some of the better-known limits are:
>>>
>>> - the number of simultaneous processes in the system
>>>  (default: 32768, but can be raised up to 268435456)
>>> - the number of ETS tables (default: 1400, can be raised  
>>> considerably)
>>> - the number of open ports and file descriptors (basically
>>>  an OS limit)
>>>
>>> Other system limits can be found in
>>> http://www.erlang.org/doc/efficiency_guide/part_frame.html
>>> and most are implementation details and subject to change.
>>>
>>> What happens if you run into a system limit, e.g. if you
>>> try creating too many ets tables, is that the operation
>>> fails with an exception. Out of memory is a rather special
>>> case, in that it brings down the entire VM.
>>>
>>> Adding a few more limits that affect individual processes
>>> rather than suffering the node-global disaster of OOM,
>>> is thus nothing new, and in that sense shouldn't be
>>> terribly controversial in itself. The reasonable /default/ is
>>> of course that processes behave as today, i.e. the heap
>>> and message queue length limits et al would be /optional/.
>>>
>>> Having said this, it is certainly important to discuss which
>>> such limits would actually be useful in practice.
>>>
>>>> How you do that thorough testing is something that needs
>>>> to be written up clearly in some new Erlang book, which
>>>> I wish you would write.  I would certainly buy it.
>>>
>>> Ok, at least one potential customer. I'll think about it. :)
>> ________________________________________________________________
>>
>>
>>   yes, please ... two customers
>>
>> ~Michael
>>
>>
>>>
>>> BR,
>>> Ulf W
>>> -- 
>>> Ulf Wiger
>>> CTO, Erlang Training & Consulting Ltd
>>> http://www.erlang-consulting.com
>>>
>>
>>
>
>
>
> -- 
> Este correo no tiene dibujos. Las formas extrañas en la pantalla son  
> letras.
> __________________________________________
>
> Clist UAH a.k.a Angel
> __________________________________________
> No le daría Cocacola Zero, ni a mi peor enemigo. Para eso está el  
> gas Mostaza que es mas piadoso.
>
> ________________________________________________________________
> erlang-questions mailing list. See http://www.erlang.org/faq.html
> erlang-questions (at) erlang.org
>



More information about the erlang-questions mailing list