CORBA 2.3.3 Getting Started Guide (NonStop CORBA 2.3.7+)

Availability and Fault Tolerance
To support continuous availability, an object-oriented runtime environment must provide fault tolerance
on the following three levels:
The system platform
The ORB
The application components
The NonStop CORBA system provides the first level of fault tolerance by running on the NonStop
Kernel operating system, which offers such features as NonStop process pairs, mirrored disk controllers,
and fault-tolerant communications subsystems.
The ORB supports fault tolerance by using TS/MP as a process manager for ORB processes. TS/MP
provides automatic restart when a server process fails.
Automatic restart is also available to application components that use TS/MP server pools.
Transaction Protection and Data Integrity
The Object Transaction Service (OTS) and Java Transaction Service (JTS), provided as a part of
NonStop CORBA, can be relied upon to provide transaction protection and data integrity. The NonStop
CORBA JTS and OTS use HP NonStop Transaction Management Facility (TMF) as the underlying
mechanism for transaction protection, keeping transaction protection and data integrity in line with HP
fundamentals.
The data stores in the Naming Service and the Interface Repository databases, which contain ORB
configuration information, are also protected by NonStop TM/MP and database software.
You can use the JTS and OTS to protect your application-specific data when the application itself needs
transaction protection or when the client has requested transaction protection.
Network Session Concentration
The NonStop CORBA system provides network session concentration to reduce the number of
connections to the NonStop system. NonStop CORBA provides network session concentration with the
use of Comm Servers. Comm Servers are NonStop CORBA system components that manage the
linkages between remote clients and local servers. Comm Servers use the following protocols:
Internet InterORB Protocol (IIOP"), as defined by the OMG specification for communication with
remote components over TCP/IP. A remote client uses a single TCP/IP port number to connect to
the ORB, regardless of the number of servers the client uses.
TS/MP protocol for communication with TS/MP server pools.
Guardian file system protocol for communication with individual processes on HP NonStop
systems.