users@shoal.java.net

Re: [Shoal-Users] detecting when contact is no longer in doubt after a missing heartbeats

From: Shreedhar Ganapathy <Shreedhar.Ganapathy_at_Sun.COM>
Date: Wed, 28 May 2008 09:29:19 -0700

Hi Mike
Thanks for asking these questions. This lets us know where we need to
add documentation of value.

Here's an explanation on how the Jxta Service Provider Implementation
works (this is the layer on top of Jxta Platform implemented in Shoal
below the GMS APIs) wrt health monitoring
http://wikis.sun.com/display/shoal/Shoal%27s+Jxta+Service+Provider%27s+Health+Monitoring+Protocol

This is work in progress and we will add additional information into the
document soon.
Let us know if you need any further clarifications.

hth
Shreedhar


Mike Kanaley wrote:
>
> Hello,
>
> Say some of the heartbeats from a group member are lost.
>
> A FailureSuspectedSignal will be sent.
>
> Then one of two situations will occur:
>
> 1) the group member is actually down in which case a
> FailureNotificationSignal is sent. OR
>
> 2) the group member is actually up and resumes heartbeats.
>
> My first question is will a JoinNotificationSignal be sent in this case?
>
> It is not clear from the documentation that this will happen.
>
>
>
> Next question.
>
> Say some of the heartbeats from a group member are lost.
>
> A FailureSuspectedSignal will be sent.
>
> Say the loss of heartbeats continues until a FailureNotificationSignal
> is sent but the group member is actually alive and well (someone
> unplugged the network cable).
>
> I am assuming when the network problem is fixed that a
> JoinNotificationSignal will happen.
>
> Is that correct too?
>
>
>
> Thanks,
>
> -mike
>