Re: Oracle 8i --- IIOP Connections for deploying EJB

In article <7oa77c$usf$1_at_nnrp1.deja.com>,   eric.davis.0246528_at_nortelnetworks.com wrote:
> In article <7nheb7$lpt$1_at_soap.pipex.net>,
> deletethissteven.chaplin_at_convergys.com (Steve Chaplin) wrote:
> > In article <37910366.9263B707_at_intasys.com>, san_at_intasys.com says...
> > >
> > >Moon Lee wrote:
> > >> I have set up a Oracle 8i server and configured to use IIOP
> > >> Connections. However, I can connect to Oracle 8i server thro IIOP
> > >> locally. When I attempt to connect to it through other machine,
> > >> connection fails! Can anyone help me to solve this?
> > >
> > >The same problem.
> >
> > I have exactly the same problem using IIOP/CORBA not EJB. I've also
> had mail from
> > at least one other person with this problem.
> >
> > I've spent a lot of time in the past with TCP/IP related problems
but
> this one has
> > me stumped. I've run the listener in trace mode and have seen an
> incoming GIOP
> > connection successfully made. However, the lisener does not seem to
be
> able to
> > connect to the database whose SID was specified in the sess_iiop
> connect string.
> > Unfortunately, the trace does not show the connect string TNS is
> trying to use.
> >
> > Has anyone got this working?
> >
> > Steve
> >
> >
>
> Same problem here. Sorry I don't have a fix. See my post from another
> news group.
>
> Subject:
> Cannot connect to service: sess_iiop - error message when
> using sess_sh or deployejb
> Date:
> Wed, 04 Aug 1999 14:14:20 -0400
> From:
> "Davis, Eric (EXCHANGE:WWP:BA36)"
> <erdavis_at_americasm01.nt.com>
> Organization:
> Nortel
> Newsgroups:
> comp.databases.oracle.tools
>
> Hello,
>
> I am having a problem using the sess_sh and deployejb tools to connect
> to a remote database instance. The use of either tool, which I presume
> uses the the same transport mechanism, results in the following error
> message: "Cannot connect to service: sess_iiop://nwwph4b8:2481:db0",
> where "nwwph4b8" is the host name, "2481" is the default iiop listener
> port and "db0" is the SID.
>
> Here are the facts. I can connect to other database instances, on
> different nodes, using these client application (sess_sh or
deployejb).
> I also can connect to the database instance discussed above when using
> the client utilities (again sess_sh or deployejb) resident on that
same
> host (i.e. nwwph4b8).
>
> The db instances are more or less "out-of-the-box" on both nodes, and
> are the same in terms of configuration options. I am starting to
believe
> that this may be a global Oracle configuration problem not related to
a
> specific db service, or an OS configuration problem.
>
> The specifics of the product are Oracle8 (8.1.5) for WinNT.
>
> If responding to this post, would you please copy me at
> "eric.davis.0246528_at_nortelnetworks.com", lest I forget to check back
for
> a response?
>
> Thanks,
>
> Eric Davis
>
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> Share what you know. Learn what you don't.
>

Success!

I have resolved the issue. Here is what I have found, that I believe was the problem. (Note that I am working in an NT environment).

The NETBIOS name and the DNS name of the node where the database instance resides are different. The NETBIOS name cannot be resolved to an address within DNS. The database instance was configured using the DNS resolvable host name. No IIOP clients can connect to the database service.

Change: Replace the existing DNS entry with the same value as the machines' NETBIOS name. Now the machine's NETBIOS name is also it's DNS alias. Replace all occurrences of the machine's old DNS alias with it's new DNS alias (i.e. it's NETBIOS name). Restart all the Oracle services. Now IIOP clients can connect.

Lesson: The Oracle processes involved in IIOP client communications perform a DNS lookup on the machine's NETBIOS name. If it cannot be properly resolved, then the IIOP client connection fails. This statement is supported by the fact that I have another instance working problem free, where that node has two DNS entries. One is the same as that nodes NETBIOS name. That node's database instances were configured using the non-NETBIOS DNS alias.

Disclaimer: Sure this theory needs further testing, but I have spent enough time on this problem already. Hope this helps with your problem.

Cheers!

P.S. This problem/solution should apply equally whether you are using EJB or CORBA, as Oracle's EJB implementation uses IIOP as the transport mechanism. In fact when writing EJB classes, you have to use the supplied tool java2_iiop to generate the necessary IIOP support classes.

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Share what you know. Learn what you don't. Received on Thu Aug 05 1999 - 07:37:55 CDT