This subsection describes the basic concept when you determine a system configuration. An execution environment that is built in the Application Server is configured of multiple processes. Each process has multiple layers for each provided functionality. These layers are called the functionality layers.
In the execution environment, you can deploy each functionality layer on different servers. You need to determine the deployment, depending on the scale and purpose of the system.
The following figure shows an example of deploying the functionality layers:
Figure 3-5 Example of deploying the functionality layers
The concept of a configuration with the following functionality layers deployed in the execution environment is explained below:
In addition to sending the HTTP requests to the Web container, a Web server processes the static contents included in the business process. The web container operates as a part of the J2EE server and functions as a base for executing the servlet and JSP. The Web server and the Web container can be deployed either on the same host or on different hosts.
If you are using an in-process HTTP server, a Web server is not required.
Hitachi recommends that you deploy one Web server for each J2EE server on which the Web container runs. In the case of load balancing, Hitachi recommends that you deploy the load balancer in front of the Web server.
After doing this, determine the system configuration by referring to the following explanation:
The CTM is the functionality that uses the OLTP technology for scheduling the requests from a client. The EJB container is a functionality that operates as a part of J2EE server, and provides the system level services such as execution and communication of Enterprise Beans and transaction management.
The CTM executes the scheduling process of IIOP requests sent to the EJB container and load balancing process. The CTM is a special functionality layer for processing IIOP requests, and therefore, the CTM is not required to be deployed on the EJB container and other hosts. The data transfer between the CTM executes the load balancing of IIOP requests. However, only the load balancing of Stateless Session Beans is executed by the CTM.
Hitachi recommends that you configure the respective load-balancing cluster configuration by setting up the ratio of CTM and EJB containers as one to many. This setup increases the throughput. You can build a system having higher expandability and performance. With cluster configurations, you can perform the partial degeneration and partial restoration, if an error occurs. The reliability and also the availability increase with cluster configurations.
Based on this, reference the following subsections and decide the system configuration:
JCA provides a supporting function for connecting to the EIS of the existing system and the database.
The connection pooling process for EIS is executed in JCA. When EIS is built on one server, the relationship between JCA and EIS is many-to-one. If EIS is built on multiple servers, the relationship between JCA and EIS becomes many-to-many. When failure occurs in the EIS connection, the reliability and availability of the system is ensured, because JCA supports the function for automatic recovery.
The Naming Service provides the naming management function to enable the use of an object by its name. The Cosminexus TPBroker provides the Naming Service. Hitachi recommends that you invoke the Naming Service by the in-process of the J2EE server.
You can use invoking by the in-process to reduce the number of processes in the Application Server. Furthermore, the individual start and stop processes are no longer required and operability will improve.
Management Server contains the functionality for operation management of the entire Application Server system. Deploy one Management Server instance on the domain where the operation management and monitoring of the system are to be performed. Although, this manual describes the configuration where you deploy Management Server on a host other than the one on which the other J2EE server processes are deployed, you may also deploy Management Server on the same host.
Invoke Administration Agent on the respective hosts where the processes, for which operation management and monitoring are to be performed, are deployed. Administration Agent executes the operation in each host on receiving the instructions from Management Server.
The operation administrator uses the Smart Composer functionality or Management Server commands for management. These commands are executed on the same host where Management Server is deployed.
For details about the system configuration where the operation management process is deployed, see 3.9 Determining the deployment of the operation management process.