Erlang on embedded Vxworks ( Re: Re: Supervisor hierarchy question)

[Francesco Cesarini (Erlang Training & Consulting)]

In response to your comments, memory usage is obviously application
dependent. Not knowing anything on your memory requirements and not
knowing anything about your application, it is very hard to judge. The
"Erlang answer" to these questions is to prototype your application and
get a proof of concept, taking measurements of memory usage when
stressing the system.

Keep in mind that when using VxWorks, you have no memory protection from
 other threads, so corrupting Erlang's memory space is a huge risk. If
it happens, there will be little information to help you in your post
mortem debugging. Also to keep in mind is that there is no commercial
port for VxWorks at the moment.

Erlang and VxWorks has been discussed on the list in the past, so I
would suggest you look at the archives as well.

Regards,
Francesco
--
http://www.erlang-consulting.com

Techie Yang wrote:
> Thanks for your hint!
> 
> So if it is correctly handled, there might be no crash due to lack of memory. Right? Then if we extend the memory to 64M, is it possible to be safe?
> 
> Basically, the crash would not be the result we want. : - ).
> 
> We are considering to use Erlang/OTP on our next product, the card is PPC860 with vxWorks, memory may be 32M.
> 
> Best Regards
> Techie
> 
> 
> 
> 
> 
>>We did it on a VX WOrks embedded system, but it was back in 1997. The VM
>>was much smaller back then. Just be very careful with your recursion
>>(Use only tail recursion so as to avoid memory bursts), and ensure you
>>have heart enabled for auto restart in case the virtual crashes because
>>of lack of memory.
>>
>>Regards,
>>Francesco
>>--
>>http://www.erlang-consulting.com
>>
>>Techie Yang wrote:
>>
>>>And is it possible to enable mnesia/SNMP on a board with just 32M RAM,  in case without huge bulks of data to be manipulated?
>>>
>>>Thanks in advance for your hints!
>>>
>>>Best Regards
>>>
>>>
>>>
>>>
>>>
>>>
>>>>Torbjorn Tornkvist wrote:
>>>>
>>>>
>>>>>Yes, Nortel's SSL-VPN products is using Mnesia in all its glory.
>>>>
>>>>Regarding Mnesia, I have a question to all of you that are also using it 
>>>>in production. What do you use for backuping Mnesia ? What function do 
>>>>you call ?
>>>
>>>>From our experience, the Mnesia backup function can eat a lot of 
>>>
>>>>memory. This is for sure related to the distributed feature and the fact 
>>>>that a stable checkpoint must be generated.
>>>>
>>>>But you need a lot of RAM to do such operation. This is the same for 
>>>>table structure updates. On some hardware, it could be difficult to keep 
>>>>several hundreds of Mo in RAM just to be safe with backups. Could this 
>>>>be related to the number of waiting messages queued before Mnesia ?
>>>>
>>>>So, I wanted to have your feedback on how you handle those 
>>>>administration Mnesia process ?
>>>>
>>>>Thank you in advance for your feedback.
>>>>
>>>>-- 
>>>>Mickaël Rémond
>>>>http://www.erlang-projects.org/
>>>>
>>>
>>>
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