Re: url probability bug fix and random number use update

[Val S. <va...@nv...>]

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