1.6.1 About Parallel Objects

Support for parallel objects has been added in release 8.0 of Oracle Tuxedo as a performance enhancement. The parallel objects feature enables you to designate all business objects in particular application as stateless objects. The effect is that, unlike stateful business objects, which can only run on one server in a single domain, stateless business objects can run on all servers in a single domain. Thus, the benefits of parallel objects are as follows:

Note:

You enable the parallel objects feature by setting the concurrency policy option to user_controlled in the ICF file. For more information, see Configuring Parallel Objects.

• Parallel objects, which are stateless, can run on multiple servers in the same domain at the same time. The resulting utilization of all servers to service concurrent multiple requests improves performance.
• When Oracle Tuxedo services requests to parallel business objects, it always looks for an available server to the local machine first. If all servers on the local machine are busy processing the requested business object, Oracle Tuxedo looks for an available server on other machines in the local domain. Thus, if there are multiple servers on the local machine, network traffic is reduced and performance is improved.

As illustrated in the following figure, if a stateful business object is active on a server on Machine 2, all subsequent requests to that business object will be sent to Group 2 on Machine 2. If the active object on Machine 2 is busy processing another request, the request is queued. Even after the business object stops processing requests on Machine 2, all subsequent requests on that stateful business object will still be sent to Group 2. After the object is deactivated on Machine 2, subsequent requests will be sent to Group 2 on Machine 2 and can be processed by other servers in Group 2.

Figure 1-1 Using Stateful Business Objects

As illustrated in the following figure, if a parallel object is running on all the servers in Group 1 on Machine 1 (multiple instances of stateless, user-controlled business objects can run on multiple servers at the same time), subsequent requests to that business object will be sent to Machine 2 and distributed to the servers in Group 2 until a server becomes available in Group 1. As long as there is a server available on the local machine, requests will be distributed to the servers on Machine 1, unless the Oracle Tuxedo load-balancing feature determines that, due to loads on the servers, the request must be serviced by a server in Group 2. To make this determination, the load-balancing feature uses the LOAD parameter, which is set in the INTERFACES section of the

Figure 1-2 Using Stateless Business Objects

UBBCONFIG file. For information on the LOAD parameter, see Modifying the INTERFACES Section.