Re: random token re-used in subsequent requests [SOLVED]

On 27 May 2016 at 09:29, André Warnier <[email protected]> wrote:
> On 26.05.2016 16:01, Vincent Veyron wrote:
>>
>> On Mon, 16 May 2016 16:38:18 +0200
>> Vincent Veyron <[email protected]> wrote:
>>
>>> Out of five different servers, the code works fine on four machines, and
>>> a different token is generated every time the page is loaded or re-loaded.
>>> On one server however, a previous token is being re-used
>>
>>
>> Hi,
>>
>> The faulty server was installed with 32-bit binaries on a 64-bit
>> processor.
>>
>> I did a clean re-install using 64-bit binaries (debian stable AMD64), and
>> the problem went away.
>>
>> ab -n 20000 -c 5 "<my test url>"
>>
>> now generates 20000 unique keys.
>>
>> Speed also increased from 40 to 70 pages/second
>>
>
> Thanks for reporting this.
>
> The above strongly hints at some flaw in the srand() of perl, when called by
> a 32-bit perl, on a 64-bit OS/machine.
> In the course of this discussion, I remember citing some article found on
> the web, which was talking about something along those lines (such as the
> fact that only the lower or upper 32 bits were being used or so).
> Maybe it is worth passing this info along to the perl (language) developers,
> at www.perl.org ?

If it can be replicated on a command line then yes.

But you will want to send the bug report to [email protected]

FWIW, if your perl is sufficiently late we use the BSD implementation
of DRAND48, so we definitely would like to know if you find an issue.

Yves (who is a perl5porter)


-- 
perl -Mre=debug -e "/just|another|perl|hacker/"