Re: [Dspam-user] Manage DSPAM memory usage

[Stevan B. <st...@ba...>]

 On Fri, 17 Jun 2011 10:24:25 -0400, Julien Vehent wrote:
> On Thu, 16 Jun 2011 14:55:01 +0200, Stevan Bajić wrote:
>> On Thu, 16 Jun 2011 08:34:34 -0400
>> Julien Vehent <ju...@li...> wrote:
>>
>> [...]
>>>
>>>  It's better now, it seems. It's been running for a few days 
>>> without
>>>  devouring memory:
>>>
>>>  $ ps -ylC dspam
>>>  S   UID   PID  PPID  C PRI  NI   RSS    SZ WCHAN  TTY          
>>> TIME
>>> CMD
>>>  S   999 18378     1  0  80   0 17264 45464 ?      ?        
>>> 00:02:56
>>>  dspam
>>>
>>>  I did not change anything in dspam configuration, but I did tweak
>>>  postgres a bit, essentialy adapting the shared_buffer. I don't 
>>> know
>>> how
>>>  that could have an influence on Dspam, or maybe it's just not
>>> related at
>>>  all.
>>>
>> It is! How high was your shared_buffer? You know that by default
>> PostgreSQL is using (I think) 64 shared buffers each having 8Kb.
>
>  I had a rather low shared buffer (16MB if I recall), I moved it to
>  512MB since I have 2GB on that machine, but the problem still 
> occured.
>  Now I reduced it to 128MB and it seems fine.
>  I'm currently reading "postgresql high performance" to better
>  understand those parameters :)
>
>> Some
>> operations lock the shared buffer and some don't. I guess that the
>> maintenance task of DSPAM is heavy using the shared buffer and this
>> results in such a high memory usage on your part. Remember that 'ps'
>> is not always capable in detecting processes using shared memory and
>> counts the shared memory as used memory.
>>
>
>  Could you explain a bit more about this? I understand that the
>  maintenance can generate high load on postgresql, loading a lot of
>  records from the disk into memory, but why having a low shared 
> buffer
>  would reflect in high memory usage on DSPAM's end ?
>
 Low? I understood that you had a high shared buffer in PostgreSQL and 
 you lowered it and since you have lowered it the memory usage has gone 
 down.


>  Julien
>
-- 
 Kind Regards from Switzerland,

 Stevan Bajić