[erlang-questions] Memory usage

Francesca Gangemi <>
Tue Sep 9 22:48:25 CEST 2008


Hi Ulf,

thanks for your suggestion, we already knew about this article but it 
didn't help.
In our case the process parsing the xml does not use a huge amount of 
memory and we don't have so many requests at the same time.
Furthermore I can't see which process is using all the memory.
The memory information says that processes_used memory is 2060858920 
(~1965MB) while the process information reports a total of  24318346 
bytes (~231 MB), adding up the stack+heap values for all the processes.

What is included in the calculation of the processes_used value?

Kind regards
Francesca

Ulf Wiger wrote:
> Hi Francesca,
>
> It sounds a bit similar to this:
>
> http://www.erlangatwork.com/2008/07/hunting-bugs.html
>
> In that case, xmerl was used, and was happily gobbling up memory
> (now, that was a 64-bit system, which of course aggravated the problem.
> OTOH the XML bits were fairly small.)
>
> BR,
> Ulf W
>
> 2008/9/9 Francesca Gangemi <>:
>   
>> Hi,
>>
>> we notice that nodes crash during a load test because they cannot
>> allocate more memory.
>> The slogan from the crash dump says
>> "eheap_alloc: Cannot allocate 3328160 bytes of memory (of type old_heap")."
>>
>> Memory information reports the following values
>> total              2468460696
>> processes     2060871072
>> processes_used     2060858920
>> system              407589624
>>
>> If then I look at the process information and I add up the Stack+heap
>> values for all the processes I get 243183460 bytes. This number is quite
>> less than the processes_used one.
>> I wonder if something else is added up to the process_used memory value.
>>
>> We run the test using R11B-3 and R12B-4.
>> There are 6000 processes running under a supervisor. They generate xml
>> requests and parse xml responses. The XML structure is quite complex and
>> its size is up to 80KB.
>>
>> The following lines report information about allocated areas
>>
>> sys_misc     3422757
>> static     14417920
>> atom_space     163860    162413
>> atom_table     91901
>> module_table     5768
>> export_table     48008
>> register_table     852
>> fun_table     3250
>> module_refs     4096
>> loaded_code     4553244
>> dist_table     555
>> node_table     299
>> bits_bufs_size     0
>> bif_timer     40604
>> link_lh     0
>> proc     3995708    3988028
>> atom_entry     316564    316276
>> export_entry     312364    312172
>> module_entry     12088    11888
>> reg_proc     6320    6104
>> monitor_sh     253288    252248
>> nlink_sh     362060    358844
>> proc_list     28    28
>> fun_entry     60724    60220
>> db_tab     12848    10416
>> driver_event_data_state     28    28
>> driver_select_data_state     1000    328
>>
>>
>> Kind regards
>> Francesca
>>
>> _______________________________________________
>> erlang-questions mailing list
>> 
>> http://www.erlang.org/mailman/listinfo/erlang-questions
>>
>>     




More information about the erlang-questions mailing list