17. Types of Concurrent Managers Internal Concurrent Manager The Internal Concurrent Manager (ICM) controls all other concurrent managers. It administers the startup and shutdown of managers as defined by their work shift, monitors for process failure, and cleans up if a failure occurs. Standard Manager The Standard Manager will accept and run any concurrent requests, as it has no specialization rules that would restrict its activities. Conflict Resolution Manager The Conflict Resolution Manager (CRM) ensure that incompatible concurrent requests do not run in the same conflict domain.
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Hinweis der Redaktion
Web Services The Web services component of Oracle Application Server processes requests received over the network from the desktop clients, and includes the following components: • Web Listener (Oracle HTTP Server powered by Apache) • Java Servlet Engine (OC4J) • Oracle Process Manager (OPMN) The Web listener component of the Oracle HTTP server accepts incoming HTTP requests (for particular URLs) from client browsers, and routes the requests to the appropriate OC4J container. If possible, the Web server services the requests itself, for example by returning the HTML to construct a simple Web page. If the page referenced by the URL needs advanced processing, the listener passes the request on to the servlet engine , which contacts the database server as needed. An HTML-based Applications module uses the following access path: 1. The user clicks the hyperlink of a function from a browser. 2. The browser makes a URL request to the Web listener. 3. The Web listener contacts the Servlet engine (OC4J), where it runs a JSP. 4. The JSP obtains the content from the Applications tables and uses information from the metadata dictionary to construct the HTML page. 5. The resulting HTML page is passed back to the browser, via the Web server.
Concurrent manager is responsible for below things too….. Managing the printer:- An Oracle Report is registered as a concurrent program too. During submission or during the definition of concurrent program, we can specify the printer where report gets printed. Concurrent manager will send the output of the program to that printer. Managing the programs completion status- For example a pl/sql concurrent program can set retcode=2 to make a program complete with warning. Hence concurrent manager not just executes the program, but it manages the completion status of the program too. Classpath of a java program:- A concurrent program can be of type java too. If for this specific concurrent program you wish to use a set of java libraries, then you can specify the path of that library in concurrent program definition. Concurrent manager will amend the CLASSPATH to reflect the path of the java library. Interaction with host concurrent program- When running a host concurrent program, the concurrent manager passes the apps password as a parameter to the unix script Tracing a concurrent program Concurrent manager enable the session trace for the concurrent program, if enable trace checkbox is checked in program definition. You can then go to user dump directory and do tkprof on the file. Optimization options:- The concurrent program definition provides an option to specify optimization mode, like choose, fist rows,all rows, rule based etc. The concurrent manager will alter the optimization mode of the session before the submission of the program. Obviously this option has no relevance to Host type concurrent program.
Concurrent Manager Characteristics: Concurrent managers are fundamental to concurrent processing. Acting as a job scheduling and execution system, a concurrent manager: • Is an executable that is registered as a program library within Oracle Applications, and which runs in its own operating system process • Runs operating system processes called target processes (often referred to as workers ),each of which can start one concurrent program at a time • Can optionally run an immediate program that runs as part of the concurrent manager's own operating system process • Can be allowed to run any concurrent program, or be specialized to run certain programs • Operates during the days and times defined by a work shift
Load Balancing Definitions The relevant hardware device, often called a server load balancer , receives the relevant network traffic for the site, and distributes it to the various servers in the cluster based on the load balancing methodology that it supports. By sending requests to different nodes within the server cluster, system performance is optimized, scalability is simplified, and application availability (a key requirement of Web-based applications) is greatly enhanced.
Load Balancing Definitions The relevant hardware device, often called a server load balancer , receives the relevant network traffic for the site, and distributes it to the various servers in the cluster based on the load balancing methodology that it supports. By sending requests to different nodes within the server cluster, system performance is optimized, scalability is simplified, and application availability (a key requirement of Web-based applications) is greatly enhanced.