Re: Finding an initial name-servive using multicasting

[Ilguiz Latypov <ilatypov diskstream com>]

Magnus,

On Tue, Mar 29, 2005 at 06:18:39PM +0200, Magnus Bergman wrote:
> * Could an IOR be made smaller?
> * Are there any other to express the same data? I've heard about
>   something called corbaloc, are those strings analogous to IORs?

1. I am a newbie with CORBA and Orbit.  There is an ORBit2 command
   line option that triggers the generation of the shortened
   "corbaloc" URL instead of IORs:

     orbit-name-server-2 -ORBIIOPIPv4=1 -ORBIIOPIPSock=2809 \
                         -ORBIIOPUNIX=0 -ORBCorbaloc=1

   The last option makes orb.object_to_string() generate strings
   in the "corbaloc" format, such as the one below.

     corbaloc:iiop:1 2 HOSTNAME:2089/%00%00%00%00%f8%97%8a%b2%eb%da%83%74%10%e1%29%59%63%66%ec%02%01%00%00%00%be%06%74%90

2. I've just applied the patch by Alejandro García Castro that
   allows to refer to the ORBit2 implementation of the naming
   service by a shortcut name ("key") such as NameService:

     http://mail.gnome.org/archives/orbit-list/2004-November/msg00015.html

   The patch allowed to use the otherwise unimplemented --key
   option of orbit-name-server-2:

     orbit-name-server-2 -ORBIIOPIPv4=1 -ORBIIOPIPSock=2809 \
                         -ORBIIOPUNIX=0 -ORBCorbaloc=1 \
                         --key=NameService

3. As for the discovery, I used the OpenSLP library and daemon to
   register the name service's host name and port number under an
   artificial service name such as "service:corbans.COMPANYNAME";.
   I understand my solution is more complicated because it
   involves 2 name servers (slpd and orbit-name-server-2).

   (I disabled the 6 second Directory Agent discovery in the
   OpenSLP library against the authors' recommendations).

   Perhaps, one could reuse OpenSLP's service attributes to store
   full IORs.  This would circumvent the standard CosNaming
   service altogether.

   I haven't tried mdns, but I will be interested hearing from
   others about it.

4. BTW, I had troubles using the Java IDL's

      orb.resolve_initial_references("NameService")
   
   The function would only send Locate queries as my ethereal GIOP
   traces show.  These queries would receive negative replies from
   orbit-name-server-2.  I ended up connecting to the name server
   with a regular orb.string_to_object() mechanism, thanks to the
   short corbaloc URL made possible by the Alejandro's patch.

> Another question is how this is supposed to function. Should every user
> always get their own name service (name space)? Should there be a system
> one also? Is the separation only of security reasons?

  ...

Regards,

-- 
Ilguiz Latypov

programmer at DiskStream
Waterloo, Ontario, Canada