[omniORB] CORBA call issues

[YaKun Wang]

Hi

I am working on a large scale closed system (not connected to the internet)
that does not use a DNS; instead it uses preconfigured host files to
minimise the impact of network failures. It is possible that these host
files may become out of sync (although this needs to be managed on the
production system).

I have met a problem where CORBA calls fail transiently. The calls originate
from an IOR-format reference.

I need to find the answers to the following questions so I can implement a
solution:

1. Is the location information encoded in an IOR a hostname or an IP
address?
2. When initiating a CORBA call, the _narrow function is used. Are there
any modifications to location information inside IOR by this _narrow
function?
3. How does CORBA find the location through this IOR-format reference,
looking up DNS to find the IP address or other methods?
4. How can I reduce the occurrence of this CORBA call error?

Regards
Yakun Wang

[Ridgway, Richard (London)]

1) It varies based on vendor and configuration. Hostname, either fully
qualified with domain or not, or an IP address. There are various
utilities that can parse an IOR and tell you this. Omniorb provides
catior, I use iona's iordump.

2) Only if a location_forward exception is thrown by the remote call -
so if you are using persistent object references & an implementation
repository type setup, yes. Or if you are doing anything fancy yourself
perhaps.

3) Vendor specific, someone with more knowledge of omniorb will have to
answer (or look at the source!)

4) Might be a silly question, but is the process at the other end
definitely still alive and communicating?

-----Original Message-----
From: omniorb-list-***@omniorb-support.com
[mailto:omniorb-list-***@omniorb-support.com] On Behalf Of YaKun
Wang
Sent: 15 August 2007 03:07
To: 'omniorb-***@omniorb-support.com'
Subject: [omniORB] CORBA call issues


Hi

I am working on a large scale closed system (not connected to the
internet)
that does not use a DNS; instead it uses preconfigured host files to
minimise the impact of network failures. It is possible that these host
files may become out of sync (although this needs to be managed on the
production system).

I have met a problem where CORBA calls fail transiently. The calls
originate
from an IOR-format reference.

I need to find the answers to the following questions so I can implement
a
solution:

1. Is the location information encoded in an IOR a hostname or an IP
address?
2. When initiating a CORBA call, the _narrow function is used. Are
there
any modifications to location information inside IOR by this _narrow
function?
3. How does CORBA find the location through this IOR-format reference,
looking up DNS to find the IP address or other methods?
4. How can I reduce the occurrence of this CORBA call error?

Regards
Yakun Wang


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[Duncan Grisby]

Post by YaKun Wang
I am working on a large scale closed system (not connected to the internet)
that does not use a DNS; instead it uses preconfigured host files to
minimise the impact of network failures. It is possible that these host
files may become out of sync (although this needs to be managed on the
production system).
I have met a problem where CORBA calls fail transiently. The calls originate
from an IOR-format reference.
I need to find the answers to the following questions so I can implement a
1. Is the location information encoded in an IOR a hostname or an IP
address?

By default, omniORB uses the IP address. You can change that with
various endPoint options as described in the manual.

Post by YaKun Wang
2. When initiating a CORBA call, the _narrow function is used. Are there
any modifications to location information inside IOR by this _narrow
function?

No.

Post by YaKun Wang
3. How does CORBA find the location through this IOR-format reference,
looking up DNS to find the IP address or other methods?

If it contains an IP address, which it usually does, there is no
lookup. If it contains a name, it uses the platform's getaddrinfo() or
gethostbyname() function.

Post by YaKun Wang
4. How can I reduce the occurrence of this CORBA call error?

You haven't said how the calls fail. What exactly is the error you get?
Have you run with omniORB's tracing on? Try running with traceLevel 25
traceInvocations 1 to see what's happening.

Cheers,

Duncan.