On Sun, Jul 09, 2006 at 02:40:41AM +0200, Lars Marowsky-Bree wrote:
> On 2006-07-07T14:08:30, Dejan Muhamedagic <[EMAIL PROTECTED]> wrote:
>
> >
> > The question is simple: Should the RA, after it has done the start
> > operation, wait until the resource is really active, essentially
> > by doing the monitor operation before reporting success?
>
> Yes. All operations performed are expected to be synchronous and must
> have completed after the RA exits.
That's how I imagined it to be.
Most server-like resources are typically run by just exec-ing a
daemon which then says bye, bye and forks off to another sphere,
so to speak. The process is detached and there is no way for us to
tell what state it is in, et cetera. The server is typically not
yet functional. In general case the only way to establish that it
has done initializing itself and can do whatever it was designed
for is to do a monitor operation.
For instance, I suppose that apache is not so heavy and doesn't
need much time to initialize, so in most situations it suffices
just to
httpd -f conf
and consider the server operational. But what happens if the
computer is really busy. When, starting cluster comes to my mind,
there is a hurd of processes contending for the cpu/disk
attention. Perhaps something like
httpd -f conf
loop until monitor_apache ok
could prevent occasional surprise.
Cheers,
Dejan
> You aren't allowed to do an asynchronous stop either.
>
> Well, there is one case where you're allowed to return from start
> without having started the resource yet - you _may_ return an error ;-)
>
>
> Sincerely,
> Lars Marowsky-Br?e
>
> --
> High Availability & Clustering
> SUSE Labs, Research and Development
> SUSE LINUX Products GmbH - A Novell Business -- Charles Darwin
> "Ignorance more frequently begets confidence than does knowledge"
>
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