[Kea-users] kea-hooks question

[Yusef Shaban]

Thanks Francis. I think I will try to create the http request and have a
timeout and if the timeout exception is thrown just return as to not block
and impact the actual request being fulfilled.

On Sep 15, 2016 3:44 PM, "Francis Dupont" <fdupont at isc.org> wrote:

> Yusef Shaban writes:
> > I am curious how the hooks lib works in kea, specifically are the user
> > built hooks called asynchronously, in that, if a user hook failed it is
> > non-blocking and will allow the request to be fulfilled?
>
> => hooks are synchronous. BTW it is a bit hard to make DHCP processing
> asynchronous, e.g., you need to keep the context without creating state
> and possibly memory leaks, but it is not impossible, e.g., DHCPv4 over
> DHCPv6 is asynchronous on the DHCPv6 side (this is why the ISC DHCP
> implementation of this (Kea follows the same model) is incompatible
> with delayed ACKs). Another point is Kea is currently not multi-threaded
> (again DHCPv4 over DHCPv6 is an exception because it uses 2 processes,
> one managing the DHCPv6 part, the other the DHCPv4 part).
>
> Regards
>
> Francis Dupont <fdupont at isc.org>
>
> PS: about your example you have a trade-off between reliable and blocking
> vs not reliable and not blocking. Note DHCP itself is not reliable,
> this means if you drop a request the client will retransmit, and on
> the other side the reply can be lost too.
>
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