autorespawn for crashed modules

[Halim Sahin]

Hi,
On Thu, Sep 30, 2010 at 10:07:05AM +0200, Hynek Hanke wrote:
> On 30.9.2010 01:01, Halim Sahin wrote:
> > What do you think about an autorespawn feature for crashed modules?
> > This would be a great improovment because the new autorespawn feature in
> > sd is only useful when the whole server crasshes.
> >    
> 
> Well, autospawn is not designed because of eliminating
> crashes :) but you are right that it is its side effect and that
> in a hackish way, it kind of improves the user experience.

Yes :-).

> On the other hand, reloading crashed modules makes quite
> good sense. Especially in the situation when they have to use
> third party libraries, which can be quite unstable (as with IBM TTS)
> and are beyond our control.

ACK.

> Would you mind first sending a proposal to the list, of how
> exactly it should work? We can than make it part of the
> documentation and then implement it.

That would make sense. However my bad english prevents me from writing
such documents :-(.

> Currently, Speech Dispatcher detects crashed modules
> and it tries to switch to another module (fallback). I think this
> is not incorrect. If your default is Festival and you do not
> have festival_server running, just restarting festival module
> again and again won't help, and it is appropriate to switch
> to e.g. espeak to keep your speech running and give you
> a possibility to resolve the problem.

Yes right but what about ipmplementing a simple counter?
That could be extended by a timestamp which shows the last time of
resuming etc.
Stopping resuming after the counter has reached 3 would be possible and
should work in most situations.

/* detected festival crash */
If (counter < 3) 
{
resume("ibmtts");
counter++;
else {
counter = 0;
set_output_module(NEXT_AVAILABLE_MODULE); // fallback from festival to espeak;
}

Ok it would be a hack but that would improove user experience.
making the resume feature configurable would sense as well.

> On the other hand, if you want to use IBM TTS, and it
> crashes from time to time, of course you want to restart
> IBM TTS, not switch to espeak.
 
That's it :-).
With regards
Halim