[asterisk-app-dev] ARI ApplicationActivated event?

[Joshua Colp]

Kevin Harwell wrote:

<snip>

>
> So then there are for sure cases where full state is not recoverable and
> a missed message(s) playback mechanism would be ideal. I guess the
> questions go back then to how useful is it and is it worth the effort?

I think, depending on the application, it's useful.

> Right now Asterisk doesn't even notify an application that it is in a
> "reactivated" state.  So either applications currently built on ARI
> don't care about syncing state on reconnection, or they use the current
> commands available to do it (and that is sufficient).  Maybe having the
> proposed extra notification would not be so useful.

I think right now this hasn't been run into enough to really be a 
substantial problem for people.

> However as applications become more complex the need may arise for an
> application to know it is in a "reactivated" state and that things were
> happening while it was away. So should we implement it at all? Are
> disconnects a real problem? Do we do it now or later?

I think sudden application termination is a problem. Controlled shutdown 
is possible if the application is written to do it.

> if the answer is "yes do it now!" then it becomes how do we implement
> it? What kind of information is enough for the majority of application
> use cases?

So - I think it depends on the application itself. Whatever is done in 
Asterisk can't completely cover the case of a restarting application in 
all cases. The application is most likely going to have its own state 
that it'll have to persist. This can get complex. Take the case where 
something doesn't want to do this. It wants to start fresh. Any active 
channels be darned! Right now I don't think that's even possible to achieve.

The gist being... this is complicated.

Geez how many times can I say "I think".

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
Check us out at: www.digium.com & www.asterisk.org