[Freeipa-devel] [PATCH] 0064 Rework task naming in LDAP updates to avoid conflicts

[Petr Viktorin]

On 07/24/2012 12:01 PM, Alexander Bokovoy wrote:
> Hi,
>
> There are two problems in task naming in LDAP updates:
>
> 1. Randomness may be scarce in virtual machines
> 2. Random number is added to the time value rounded to a second
>
> The second issue leads to values that may repeat themselves as time
> only grows and random number is non-negative as well, so
> t2+r2 can be equal to t1+t2 generated earlier.
>
> Since task name is a DN, there is no strict requirement to use an
> integer value.  Instead, we can take time and attribute name. To get
> reasonable 'randomness' these values are then hashed with sha1 and use
> the resulting string as task name.
>
> SHA1 may technically be an overkill here as we could simply use
>
>    indextask_$date_$attribute
>
> where $date is a value of time.time() but SHA1 gives a resonable
> 'randomness' into the string.

What kind of randomness do you mean? SHA1 is deterministic, it doesn't 
add any randomness at all. It just obscures what's really happening.
Same with repeating [tasktime, attribute] two times.



 > -        root_logger.debug("Task id: %s", dn)
 > +        root_logger.debug("Task id: %s", str(dn))
This change is unnecessary; the "%s" means "convert to str".



> I was hit by this issue today, see
> https://fedorahosted.org/freeipa/ticket/2942
>



-- 
Petr³