CORBA 2.3.3 Programmer's Guide for C++

Configure application server processes as server pools. NonStop CORBA then uses the capabilities
of TS/MP to spread the workload among multiple processes, adds new processes as needed, and
provides load balancing.
Configure the Comm Server, LSD, ILSD, and/or BSD processes in your NonStop CORBA system
to use Parallel Library TCP/IP, so that a single TCP/IP port is shared by multiple communications
processes.
Increase the number of Comm Server processes to support increased request traffic.
Add multiple instances of NonStop TCP/IP to the NonStop CORBA system to provide additional
external port connections.
If your application performs thread-blocking operations, write a multithreaded server to increase
the number of threads per process.
Using Stateless Objects and Server Pools
NonStop CORBA uses TS/MP server pools (called server classes in TS/MP documentation) internally
for many of its own processes. In addition, you can write your own applications to take advantage of
server pools. A server pool lets your application scale across processes to increase capacity. It also
increases throughput by creating new server processes when existing ones are blocked by
process-blocking operations, such as access to databases.
To obtain the scalability and throughput advantages of server pools, you must write your applications to
use stateless objects. You can address a stateless object within a server pool with a single object
reference, as if it were one logical object, regardless which server process it resides in. This capability
gives server pools an advantage over multiple stand-alone servers.
Writing Your Application to Use Server Pools
To use server pools, you do the following in your application:
In profile@ORB for the server, set tsmp_server to true and specify a PATHMON process
name and a server-class name.
In the POA in the CORBA server application, ensure that the proprietary state policy has a value of
STATELESS. You can do this either by setting the lifespan policy to PERSISTENT or by directly
setting the state policy to STATELESS.
Note
The use of server pools provides a number of other advantages, including availability, automatic load
balancing, and process management (allowing the operator to configure, monitor, start, and stop
processes). For further information, refer to the TS/MP System Management Manual.