Re: url probability bug fix and random number use update

[Robert I. <cor...@gm...>]

Hi Vlad,

On Sun, Jun 13, 2010 at 8:38 AM, Val Shkolnikov <va...@nv...> wrote:

> Hi, Robert,
>
>
> *From:* Nadia and Val Shkolnikov <nv...@ya...>
>
> *To:* curl-loader-devel <cur...@li...>
> *Sent:* Fri, June 11, 2010 8:43:13 PM
>
> *Subject:* Re: url probability bug fix and random number use update
>
> Hi, Robert,
>
>
> *From:* Robert Iakobashvili <cor...@gm...>
> *To:* curl-loader-devel <cur...@li...>
> *Sent:* Wed, June 9, 2010 11:22:27 PM
>
> *Subject:* Re: url probability bug fix and random number use update
>
> Hi, Val,
>
> On Wed, Mar 24, 2010 at 3:36 AM, Val Shkolnikov <va...@nv...> wrote:
>
>> Hi Robert,
>>
>>
>> *From:* Val Shkolnikov <va...@nv...>
>>
>> *To:* curl-loader-devel <cur...@li...>
>> *Sent:* Sun, March 21, 2010 9:13:04 PM
>>
>> *Subject:* Re: url probability bug fix and random number use update
>>
>> Hi Robert,
>>
>> *From:* Robert Iakobashvili <cor...@gm...>
>> *To:* curl-loader-devel <cur...@li...>
>> *Sent:* Sun, March 21, 2010 12:02:05 AM
>> *Subject:* Re: url probability bug fix and random number use update
>>
>> Hi Val,
>>
>> On Sun, Mar 14, 2010 at 8:54 AM, Robert Iakobashvili <cor...@gm...
>> > wrote:
>>
>>> Hi Val,
>>>
>>> On Mon, Mar 8, 2010 at 7:16 AM, Val Shkolnikov <va...@nv...> wrote:
>>>
>>>> Hi Robert,
>>>>   There is a major bug in the curl-loader regarding use of the
>>>> FETCH_PROBABILITY tag.  In loader_fsm.c, svn rev 574, line 1359 is
>>>>
>>>> cctx->url_curr_index =  (size_t) url_next;
>>>>
>>>> The url index is updated but not the url pointer.  The result of this
>>>> bug is that all urls are selected regardless of the probability somewhat
>>>> uniformly.
>>>>
>>>> While debugging this I also reworked the use of probability in the
>>>> curl-loader to produce better pseudo-random numbers and also added a tag
>>>> RANDOM_SEED that lets you control the seed.  I am attaching the patch
>>>> against svn rev 574.  To use it
>>>>
>>>> cd curl-loader
>>>> patch -p3 <curl-loader.patch.574+vs6
>>>>
>>>
>>> Applied the patch, thanks!
>>>
>>>>
>>>> I also noticed that the tag FETCH_PROBAILITY_ONCE is not used, but will
>>>> let you decide whether it's worth to keep.
>>>>
>>>
>>> Please, look at the latest version in svn. Thanks!
>>>
>>> The array of url_fetch_decision was allocated per client only, when
>>> FETCH_PROBAILITY_ONCE was defined.
>>> The array is used to cache the fetching decision and to decrease
>>> the calls to random() for high-load testing.
>>>
>>> In most of the cases, however, it will be of no use, and it was corrected
>>> not to use url_fetch_decision array, when it is not supposed to be
>>> allocated.
>>>
>>>
>>
>> Have you a chance to look at the version in svn and try the changes made?
>> Thanks!
>>
>> --
>> Truly,
>> Robert Iakobashvili, Ph.D.
>> ......................................................................
>> www.ghotit.com
>> Assistive technology that understands you
>> ......................................................................
>>
>> Sorry, a bit busy.  I might have a chance to integrate the new code into
>> mine next week.
>> /Val
>>
>>  I reviewed your code and it looks good.  One minor change I suggest
>> which is not terribly important if you think your code is clearer.  The
>> patch is attached.
>> /Val
>>
>>
> Could you, please, try the code from subversion and say, if it works
> for your settings?
> Thank you in advance.
>
> --
> Truly,
> Robert Iakobashvili, Ph.D.
> ......................................................................
> www.ghotit.com
> Assistive technology that understands you
> ......................................................................
>
> I'll get to it this weekend, promise :-).
> /Val
>
> OK, loaded rev 577, compiled from scratch and tested with my usual load,
> everything looks good.
> /Val
>
>
Thank you very much for your assistance.
Releasing the fixed version.


-- 
Truly,
Robert Iakobashvili, Ph.D.
......................................................................
www.ghotit.com
Assistive technology that understands you
......................................................................