Re: [Anima-signaling] GRASP issue 51: Flooded objectives

[Brian E Carpenter <[e-mail]>]

Hi Toerless, just drilling down on two points (I have not ignored the rest,
but these condition other aspects):

On 05/08/2016 20:34, Toerless Eckert wrote:

...
>> 1. We specify that the source address is cached with the flooded objective, and that
>> multiple copies are kept if there are multiple sources.
> 
> Yes, but "source" really must be the ASA transport address, aka: 
>    source = {ACP-ULA-IPv6-address, proto=TCP, ASA-GRASP-TCP-port}

Here I have a little problem. Unless you plan to use GRASP messages for
the entire process, it isn't GRASP's business what protocol and dynamic
port are to be used. So I think the protocol and the port need to be
fields in the flooded objective itself, not derived automatically by
GRASP. Does that make sense?

...
> 
> If the announcer of a flood sync announce dies, how would its cache entries
> ever be deleted ? On nodes that have an ASA interested in the objective,
> the ASA can look at expiry time and tell GRASP to expire the entries. But
> how about nodes without such ASA ?

Is it a problem? The useless flooded objective would sit there until the
cache overflows and it gets deleted by the LRU algorithm.

...
> 
> Aka: expiry_time looks to me like a logical GRASP header parameter so that
> we can GRASP without ASA expire flood sync cache entries.

We can do that. It's a choice: extra bytes in every flood message versus
no default expiry mechanism, just LRU cache expiry.

I'll review all your points after we clear these ones up.

Thanks
    Brian