Re: Fault tolerance

Hello Mark,

On Tue, Nov 15, 2005 at 01:50:00PM -0800, Mark van den Boer wrote:
> We are looking to increase the fault tolerance of our systems. The basic configuration will
> be: two functionally identical servers (S1 and S2), each running a set of CORBA daemons.
> If a client goes to the name service of S1 to resolve a name to an IOR, the client can get
> equivalent functionality by going to S2 to resolve the same name to an IOR.
> 
> Ideally, we would like the client to be unaware of how many servers there are: there might
> only be one, or there might be more. If the service is not available on S1, then the same
> service should be retried transparently on S2 (multiple profiles?). I assume that the servers
> would have to know about each other in this case (they do know about each other).
> Is such a thing possible with ORBacus? Are there any code examples around to do this?

This is certainly possible with Orbacus, since it supports the concept
of a muilt-profile IOR. Essentially, multiple addresses are represented
as multilple tagged profiles within a single IOR, providing the notion
of automatic retry that you are looking for. 

To do this, you would have to look into merging seperate IORs into a
single IOR. Orbacus provides the 'iormerge' utility for doing this.

> Another acceptable solution for us would be to have the client know in advance the list of servers
> that can provide equivalent functionality. When the client wants to get an IOR, it could
> contact the name service on each server, to get the IOR for the desired service on that server.
> When the client has these IORs, can the client then combine these IORs into a multiple profile
> IOR, in order to have the retry with another IOR done automatically? If IOR merging by clients
> is possible, is there a code example around?

This basically amounts to the same thing as the previous paragraph, except
now you are specifying where the two IORs are coming from. Also, your
application would have to handle the combining of the IORs using the
'iormerge' utility.

Please note that the 'iormerge' utility is not available in the
evaluation version of Orbacus, but is available in the commercial
version. This can be downloaded for $99 at the Orbacus website
(http://www.orbacus.com).
 
> Thanks,
> Mark van den Boer
> 

Cheers,
Dave

-- 
David Weir                          
Team Orbacus - Your CORBA Source
E-Mail: [email protected]
WWW: http://www.orbacus.com
_______________________________________________
OB-Users Mailing List - [email protected]
http://mail.ooc.nf.ca/mailman/listinfo/ob-users
Visit our support FAQ before you send a message.
http://www.orbacus.com/faq/support.html