CORBA 2.6 Administration Guide
Client System
Remote clients, or network clients, are application processes that reside on other systems and other vendors ORBs. They act
as CORBA clients to CORBA application objects or any of the COS services that reside on the NonStop system. They
normally interact with those services through the Location Service Daemon (LSD) and the Comm servers. The interaction
between the remote clients and the remote services is always done through the standard IIOP protocol.
Configuration Database
Execution information required by NonStop CORBA is maintained in a database called the configuration database. This
database is built during the product installation and configuration process. Configuration information stored in the
configuration database is dynamic. Changes to the data are made by:
Users of the NonStop Distributed Component Console●
Users of the configuration management tool (cfgmgt)●
NonStop CORBA servers●
All NonStop CORBA programs use the configuration database to obtain values that govern the behavior of the program. For
example, the configuration database identifies the transport protocols used by the server. Some CORBA servers place
information into the configuration database. For example, the naming service stores the root naming context object reference
into the configuration database. The configuration database enables NonStop CORBA 2.6 to use implementation-specific
data. Since these data are obtained from a database instead of appearing in the server code, the servers can be portable.
Comm Server
The Comm server is a component of NonStop CORBA 2.6 that provides connectivity to applications for network clients.
These clients obtain the benefits of the Comm server without any special programming. CORBA requests and responses may
be routed through the Comm server based on information contained in the interoperable object reference used by the client.
The Comm server provides two benefits:
It acts as a gateway to facilitate communication between network clients and application servers on the NonStop
CORBA system.
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It acts as a network resource concentrator thus enabling construction of large-scale servers.●
As a gateway, the Comm server enables network clients to interact with NonStop CORBA servers. In some cases the servers
do not directly support the IIOP protocol that network clients must use. This is true in the case of servers hosting stateless
objects. Each request to a stateless object may be routed to a different server-pool process. Here the Comm server is used to
interact with the TS/MP facility to perform the routing. Without the Comm server, network clients could not make use of
these stateless objects.
As a network resource concentrator, the Comm Server makes efficient use of network resources. For large-scale systems
having many CORBA clients and servers, the Comm server manages network communications between network clients and
NonStop CORBA servers, thus reducing the demand for TCP/IP ports (a potentially scarce resource on the system). A single
Comm Server process may handle many network clients simultaneously; however, depending on needs of your system,
multiple Comm servers can be configured. Using multiple Comm Servers allows larger volumes of traffic to be handled
because the load is spread across multiple processors.
Parallel Library TCP/IP
Another way to increase capacity and fault tolerance is to configure the IIOP connectivity components of your system
(Comm Server, LSD, ILSD, and BSD processes) to use Parallel Library TCP/IP. With this configuration, multiple Comm
Server processes running in a pool can share the same port. A round-robin filter distributes the incoming connections among
the Comm Server pool. When configured this way the Comm Server pool appears as a single IP host to the outside world.
Figure 17 shows the original way of configuring TCP/IP in a NonStop system. Note: