On Sat, May 3, 2014 at 2:01 AM, Akila Ravihansa Perera
<[email protected]>wrote:

> Thanks Nirmal, that was very helpful.
>
> But what about a member deactivation event as a result of scale-down?
>

It is the same as activation. Autoscaler decides to scale-down.... and once
member is ready to be shutdown, cloud-controller would terminate the member
and send out a member terminated event.

>
> Just to clarify, if we are going to implement topology event extension
> points for Cartridge Agent, then it should also process the complete
> topology and complete tenant events only once according to this
> pattern?
>
>
So, the best practice would be, to listen for the complete* events in order
to initialize and then identify the events that you would want to listen
and act only upon those events, thereafter.

>
>
> On Sat, May 3, 2014 at 1:37 AM, Nirmal Fernando <[email protected]>
> wrote:
> > Hi Akila,
> >
> > Complete* events are there only for the system to withstand a restart.
> So,
> > each of the server would initially wait till it receives the complete*
> event
> > and adjust it state to the current system state and then from that point
> > onwards, each server would react on the events that occurs.
> >
> > If I take your sample, in the case of member activation during a server
> life
> > time, servers would listen to MemberActivatedEvents and process.
> >
> >
> > On Sat, May 3, 2014 at 1:09 AM, Akila Ravihansa Perera <
> [email protected]>
> > wrote:
> >>
> >> Hi Imesh,
> >>
> >> I noticed that you have made a commit [1] that will make the LB to
> >> process complete topology and complete tenant events only once. But
> >> could you explain the reason for it to be like that? Shouldn't the LB
> >> be aware of topology changes that might occur in the future? It might
> >> not be aware of members getting active/inactive dynamically.
> >>
> >> I'm just trying to understand the workflow here, would really
> >> appreciate if anyone can provide some background information on this.
> >>
> >> Thanks!
> >>
> >>
> >> [1]
> >>
> https://github.com/apache/incubator-stratos/commit/783197eaba9edd70212ca70b39679502274fd230
> >>
> >>
> >> --
> >> Akila Ravihansa Perera
> >> Software Engineer
> >> WSO2 Inc.
> >> http://wso2.com
> >>
> >> Phone: +94 77 64 154 38
> >> Blog: http://ravihansa3000.blogspot.com
> >
> >
> >
> >
> > --
> > Best Regards,
> > Nirmal
> >
> > Nirmal Fernando.
> > PPMC Member & Committer of Apache Stratos,
> > Senior Software Engineer, WSO2 Inc.
> >
> > Blog: http://nirmalfdo.blogspot.com/
>
>
>
> --
> Akila Ravihansa Perera
> Software Engineer
> WSO2 Inc.
> http://wso2.com
>
> Phone: +94 77 64 154 38
> Blog: http://ravihansa3000.blogspot.com
>



-- 
Best Regards,
Nirmal

Nirmal Fernando.
PPMC Member & Committer of Apache Stratos,
Senior Software Engineer, WSO2 Inc.

Blog: http://nirmalfdo.blogspot.com/

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