When you are using CTM, you can control the number of concurrent executions of a Stateless Session Bean.
CTM is a group of processes independent of the J2EE server. The number of concurrent executions is controlled when the invocation of the Stateless Session Bean between the EJB client and J2EE server is relayed, and the Stateless Session Bean is invoked. When using CTM, the number of concurrent executions will be controlled in each J2EE application.
By controlling the number of concurrent executions (flow control) with CTM, you can perform the following tuning:
The following figure shows an example of controlling the number of concurrent executions of a Stateless Session Bean with CTM:
Figure 8-5 Example of controlling the number of concurrent executions of a Stateless Session Bean with CTM
Note that the number of concurrently executed threads can also be changed dynamically with CTM in a running CTM daemon.
For details about the CTM functionality to control the number of concurrent executions, and the procedure to dynamically change the number of concurrently executed threads with CTM in a running CTM daemon, see 3.4 Controlling volume of the request flow in the uCosminexus Application Server Expansion Guide.
Hitachi recommends the control of the number of concurrent executions using CTM. Note that when you use CTM to control the number of concurrent executions, you can use the instance pooling functionality of the EJB container and controlling the number of concurrent executions at the same time.
The advantages of using CTM for controlling the number of concurrent executions, in addition to the use of the functionality of EJB container for controlling the number of concurrent executions are as follows: