Re: IP Acounting Idea for 2.5

[Harald Welte <laforge@gnumonks.org>]

On Mon, Apr 16, 2001 at 12:07:31PM +1000, Manfred Bartz wrote:
> 
> If there really is a performance issue with a few hundred rules, then
> it can be overcome by grouping rules in separate custom chains.  F.e.
> if you have 1024 rules create 32 custom chains with 32 rules each.
> Then have 32 rules in your main table which jump to the appropriate
> custom chain --> maximum rules traversed by each packet = 64.

still.. if you want to log multiple class B's it's a PITA, especially
if your ruleset changes and you have to atomically replace all chains
in one table to update the ruleset from userspace->kernel.

> There is another issue with logging in general:
> 
>                 *COUNTERS MUST NOT BE RESETABLE!!!*
> 
> Resetable counters guarantee that no two programs can co-exists if
> they happen to reset the same counters.

That sounds like crap (sorry). Counters are resettable, and will be.
If you run two applications resetting counters individually, you have
a problem with your applications.

> All logging counters should be implemented with 32bit or 64bit
> unsigned integers.  Any software using correct unsigned integer

they are uint32 right now.

> arithmetic can then simply subtract a previous value from the current
> value to get the difference.  This works reliably across counter
> wrap-arounds.  There is absolutely *no need for reset* !

so why are your applications resetting counters then? Nobody forces you
to reset them right now.

> Manfred Bartz
> ---------------------------------------------------------------

-- 
Live long and prosper
- Harald Welte / laforge@gnumonks.org                http://www.gnumonks.org
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