CORBA 2.6.1 Programmer's Guide for Java

Static invocation

dynamic invocation

. For example, whether the client will use a predictable set of object interfaces or might

find out about new interfaces at run time.

Object lifecycle. Issues such as creating, locating, and releasing objects, including how to use the Naming Service.

Server selection. For example, whether to request a specific server or use any server that can host an object interface.

Server pools. Implications of the use of server pools and whether the use of server pools must be transparent to the application.

Transaction management. Whether a client or object has responsibility for managing nested transactions.

Concurrency. Whether clients or an object must coordinate concurrent access to data, and whether the client requires threads.

Interoperability. For example, ensuring that a client developed on some other platform can interact with NonStop CORBA servers.

Tuning Applications for Performance

The following sections provide some performance tuning suggestions for NonStop CORBA applications.

Choosing the Most Efficient Transport Protocol

For remote object references, the IIOP protocol (which uses TCP/IP) must be used for transport. However, for local object references, NonStop

CORBA provides two proprietary transport protocols that can improve application performance:

GIOP over TS/MP, which addresses a stateless object through a server pool.

GIOP over the Guardian file system, which uses Guardian file-system addressing to access a specific instance of an object (that is, a

stateful object). Guardian file-system addressing uses a process name to specify a particular server process.

For object references that will always be local, HP recommends the use of GIOP over TS/MP wherever possible, since this protocol also

provides the availability, scalability, and load-balancing advantages of server pools. For local object references where GIOP over TS/MP cannot

be used, HP recommends using GIOP over the Guardian file system.

In addition to local object references, you can also use GIOP over TS/MP and GIOP over the Guardian file system for references to NonStop

CORBA objects on other NonStop systems that can be reached through the Expand network. In some cases, these two protocols may provide

an improvement in performance compared to IIOP over TCP/IP; however, the comparative performance in such cases depends on the

application and the network configuration.

GIOP over TS/MP is configured by using an application profile that sets

tsmp_server to TRUE. GIOP over the Guardian file system is configured

by using an application profile that sets

fs_server to TRUE. For further information about configuring these two protocols, see the Application

Profiles: Configuring and Managing an Application.

Taking Advantage of Concurrency

IWhen your application has the potential for concurrency (that is, it includes thread-blocking operations but not process-blocking operations),

you may be able to use multithreading to reduce the number of processes required to handle a given workload. For details, see the

Writing

Multithreaded Applications.

When your application performs process-blocking operations, you can take advantage of process concurrency by using server pools.

Adjusting Process Priorities

In general, processes that provide services should have higher priority than processes that request those services. More specifically, consider

the process flow as a river at whose delta are services (both COS and application) or entity objects, whose tributaries are control objects, and

whose source streams are Comm Server, TCP/IP, and similar processes that are conduits for client requests. The delta should have higher

priority than the tributaries, and the tributaries should have higher priority than the source streams.

Chapter 8. Writing Multithreaded Applications Chapter 10. Porting CORBA Applications to

NonStop

CORBA