[Openais] Some basic Q:s

Steven Dake sdake at mvista.com
Thu Oct 7 11:20:15 PDT 2004


Torm,

responses inline

On Thu, 2004-10-07 at 05:33, Tor-Erik Malen wrote:
> Hi
> 
> I'm looking into openAis. I've worked with the test programs and tried to 
> figure out how it works. Now I have some issues I would like to get 
> clarified. Any help? 
> 
> thanks torm
> 
> - is there a 1-1 mapping of component and process? seems like the first 
> registered component is "hidden" if one process registers two components.

A process may have one or more AMF components.  I don't understand what
you mean by hidden.

> - each registered component has to have a unique name?

Yes the component name is used to uniquely identify a component within
the system.  The spec might allow a unique name just within a service
group, although openais requires names to be unique throughout the
entire deployment for now.  We may fix this up in the future.

> - how are CSI "defined" into the "cluster"? Unclear how CSI:s are defined and 
> then "assigned" to components.

The CSI assignment occurs as part of the AMF framework.  It is very
complicated and not quite right yet in openais.  But basically a CSI is
named based upon the protection group.  So 

> - does the aisexec start/stop/restart processes?

No although this could be an extension to openais.  There is some
expectation that for non-sa aware components, the aisexec should start
and stop processes, but we have not yet tackled that problem.

> - is there a configurable mapping of component-to-process? I.e., can I say 
> that BTW this component is handled by this process.

I'm not sure how this would help but no there is not..  The only place
that this might help is non sa-aware components, which still need a bit
of work in openais.  We wanted to handle the sa-aware component case
well first, which I think we have pretty well handled.

> - can you configure components (processes) to be started when a node (aisexec) 
> starts

This is possible through the standard init process (in Linux) by
starting aisexec at a higher priority then the remaining services.

> - can aisexec be "commanded", e.g.,  to set a component/CSI into a specific 
> state? 

No....  This is not specified by the sa forum (yet) but we will have
this capability in 2005 with the configuration API.  The configuration
API will allow us to configure and command components externally from
management software.

> - are non ais-processes supported?

poorly

> - is there a group.conf guide, I'm not able to figure out how to use it
> - what shall the network.conf bindaddress actually be set to?
> 

The quickstart guide covers it, but its a little terse..  It should be
your class C address.  So for example, if your cluster addresses are
192.168.1.20 and 192.168.1.234, bindnet should be 192.168.1.0.  It could
actually be 192.168.1.220 if you wanted, because openais takes
192.168.1.220 and ands it with 255.255.255.0.  Then it tries to match an
interface by taking the local address 192.168.1.234 and anding it with
255.255.255.0.  In this case, both and operations return 192.168.1.0
which gives a match and binds to the interface.

> network.conf trials
> Got it working by mistake, tried network address but crashed the aisexec when 
> components started to work, a nodes address just made the nodes occasionally 
> detect each other but not considering the other belonging to the cluster. Got 
> it working by mistake when I just put a IP-addr belonging to the network.
> 

The crash is a bug...  Please let me know your machine network addresses
and your network.conf that caused openais to crash.  I'd like to fix any
and all crashes even if caused by misconfiguration.

Your technique of putting an ip addr belonging to the network will work
because of the logic above.

Regards
-steve
> 
> 
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