Re: [sqlmap-users] CPU utilization

[Miroslav S. <mir...@gm...>]

Hi.

That's because, when you do the urllib2 page request, current thread
goes into blocking state - no events here, just plain raw CPU power.
If you do it with 30 threads for example, all of them go into blocking
state. I repeat, python's standard module Urllib2 doesn't support
asynchronous page retrievals (neither any other).

Could you please be so kind and review
sqlmap/lib/techniques/blind/inference.py, methods bisection(...) and
getChar(...), and advise with some concrete solution. We'll be more
than happy to hear from you.

Kind regards.

On Mon, Mar 15, 2010 at 1:58 PM, Kasper Føns <th...@ma...> wrote:
> Hi
>
> I still don't get why sqlmap is using that much cpu then?
>
> On 15-03-2010 13:49, Miroslav Stampar wrote:
>>
>> Hi Kasper.
>>
>> Threads are indeed in a blocking state while retrieving page content
>> (basic socket blocking). Basic python urllib2 doesn't support
>> asynchronous page retrievals, but we could put this on a feature
>> request list (http://eventlet.net/doc/,
>> http://twistedmatrix.com/trac/).
>>
>> Kind regards.
>>
>> On Mon, Mar 15, 2010 at 1:24 PM, Kasper Føns<th...@ma...>  wrote:
>>
>>>
>>> Dead Miroslav
>>>
>>> That was not the point I was trying to make. It would ofcourse be nice to
>>> utilize the 100% of my computer when a program wants to, but I can see
>>> that
>>> python is crippled in the matter. But what I was asking about was:
>>> I think it is strange that sqlmap uses 50% of my cpu - What operations
>>> could
>>> require that much cpu? It seems that if a connection to a target is slow,
>>> sqlmap still uses 50% of the cpu. Is it besy-waiting for the thread that
>>> is
>>> doing the I/O operation to complete?
>>>
>>> I'll try again:
>>> I would see sqlmap's main bottlenet as the internet connection. I can't
>>> find
>>> anything to justify to use my CPU as much as it does. Therefore I think
>>> some
>>> thread is besy-waiting, which really cripples the system (especially if I
>>> only had 1 CPU). So my question is, is it busy-waiting?
>>>
>>> PS: Thanks for the nice link. Was interesting reading.
>>>
>>> /Kasper
>>>
>>> On 15-03-2010 13:17, Miroslav Stampar wrote:
>>>
>>>>
>>>> Dear Kasper.
>>>>
>>>> Python has an "technical" issue dealing with multithreading programs.
>>>> In part that it can't run threads on multiple cores, it has a really
>>>> nasty "GIL" problem which is discussed here:
>>>> http://www.snaplogic.com/blog/?p=94. Threading of sqlmap really speeds
>>>> it up, but the side effect is that CPU-throttling you are talking
>>>> about, especially in a high number of threads used.
>>>>
>>>> Kind regards.
>>>>
>>>> On Mon, Mar 15, 2010 at 12:55 PM, Kasper Føns<th...@ma...>    wrote:
>>>>
>>>>
>>>>>
>>>>> Hello sqlmap users.
>>>>>
>>>>> I have a question about how sqlmap utilizes the cpu. On my computer the
>>>>> CPU being utilized is nearly always 50%, and since I have two cores I
>>>>> suspect some thread to be in deadlock or maybe doing busy-waiting.
>>>>> If using busy-waiting, I would suggest using an event-based approach
>>>>> instead.
>>>>>
>>>>> /Kasper
>>>>>
>>>>>
>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>> Download Intel&#174; Parallel Studio Eval
>>>>> Try the new software tools for yourself. Speed compiling, find bugs
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>>>>> See why Intel Parallel Studio got high marks during beta.
>>>>> http://p.sf.net/sfu/intel-sw-dev
>>>>> _______________________________________________
>>>>> sqlmap-users mailing list
>>>>> sql...@li...
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>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>>
>
>



-- 
Miroslav Stampar

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