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Communications Daemon The database administrator uses the console to provide management of the communications daemon by selecting Tools, Daemon Manager. Daemon Manager enables the database administrator to manage and monitor the interaction of the local communications daemon and the remote intelligent agents by configuring items such as the TCP/IP port, polling intervals, and maximum connection counts. In addition, the database administrator can observe which applications and nodes have pending events and jobs.
Navigator is the most widely used part of the Enterprise Manager console. It behaves much like the Windows Explorer, so the interface is intuitive and immediately usable. Right-clicking any object reveals a mouse menu to create new tree views, access Navigator functions, or use related Database Administration Tools.
From the mouse menu, select Split View to create a reference point for the top of a tree in a new view easily accessible using tabs at the top of the Navigator window. In a complex database or operating environment, the tree views make accessing the parts of the environment of interest more efficient (see Figure 9.4). Filters provide an alternative method of limiting branches of the tree to objects of interest. For example, if all general ledger objects begin with "GL_," a filter value of GL_% will limit objects below the filter in the tree structure to those that belong to the general ledger system.
The same menu enables the database administrator to create new objects of the same type or delete existing objects. Some object changes are possible directly from Navigator using Quick Edit, while more complex changes may require accessing one of the Database Administration Tools that operate on the selected object by selecting Related Tools.
NOTE |
Because the mouse menu is context sensitive, the operations available vary widely across different objects. |
Navigator is also the source of components for Map. To add an object to a map, simply drag the object from Navigator to Map and drop it where you want it on the map.
Using Navigator, a single administrator can access every object in every database, create new objects, and delete existing objects without writing a single SQL statement. Navigator easily becomes the database administrator's primary interface to manually query and alter databases and their objects.
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Map provides a geographically oriented means to monitor the status and basic information concerning databases, nodes, listeners, and Web servers, as well as groups of these four objects. Maps of Asia, Europe, Japan, the United States (refer to Figure 9.2), and the world are provided with the product, but any bitmap file (*.BMP) is a valid map. The map doesn't even have to be geographical. Consider organizational charts, business process flows, and network diagrams as alternative maps. The capability to switch quickly between maps from the Console toolbar enables many views of the enterprise.
Used in conjunction with remote intelligent agents, Map indicates the status of each object on the map with a small signal flag. Green signal flags mean all is well. Yellow flags indicate that some condition requires attention, and red indicates a serious problem. The Event Management component of Enterprise Manager enables the database administrator to define conditions and thresholds necessary to trigger changes in status indicated by the signal flags. Double-clicking a Map object starts a view-only Quick Edit of the object. Database Administration tools, usually started from the Console, can be started directly, specific to an object if the object is selected on the map.
The Enterprise Manager Job Scheduling component, known as Job, provides a way for database administrators to automate tasks at specific times or based on events in the operating environment. Scheduling is especially valuable in complex environments with many systems.
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Job can perform any tasks requiring operating systems commands or SQL. The remote agent handles actual execution independently of the Enterprise Manager console.
NOTE |
Job is not usable if Oracle Intelligent Agent is not installed and configured. |
Job comes with a variety of predefined tasks ready to configure and schedule. The process for creating a job is best explained using an example. To schedule an export of a remote database, start by selecting J ob | Create Job from the Enterprise Manager menu bar. The resulting window contains four tabs: General, Tasks, Parameters, and Schedule.
Starting with General, give the job a name and description. Then, select the destination type and a destination. To perform a database export, the destination type should be "Database." Next, move to the Tasks tab. There are over a dozen database and system building block tasks available to configure a job. Select the Export task from the Available Tasks list and move it to the Selected Tasks list. More complex jobs are composed of multiple tasks arranged in the required order.
Next, select the Parameters tab, where configuration information for each task in a job is managed. For a simple export, select the Select Export Objects button and determine whether you will export the entire database or specified users and tables. Select the Advanced Export Options button to select the parameters to pass to export when it runs (see Figure 9.5).
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TIP |
If there are no objects in the Available Tasks list, go to Navigator and create a database group in the Database Groups folder. The database groups make up the Available Tasks list. |
The export job is now ready to schedule. Select the Schedule tab and define when the job should run. Pressing the Submit button saves the job; it is ready to run at the specified time. The job name and description are displayed in the Jobs console window when the Job Library tab is selected. Information on active and complete jobs is available from other tabs.
Job is an easy-to-use and well-organized job scheduling system that gives database administrators the ability to automate tasks on diverse systems directly from the Enterprise Manager console. However, it is no substitute for the more robust job scheduling components of the comprehensive systems management packages that provide features such as job restart and job triggers based on the existence of a file on remote systems. The key to using Job to its full potential is to understand your job scheduling requirements. If you are currently using cron to schedule all your UNIX-based jobs, Job is a huge improvement. If you are thinking about implementing a more robust job scheduling process for your entire operation as part of an enterprise-wide systems management strategy, you may find other products more suitable.
The Event Management System (EMS) is the Enterprise Manager component that monitors the health and welfare of remote databases and the services that make them available to applications. Unlike Job, which triggers tasks on a specific schedule, EMS works with remote intelligent agents to constantly monitor for unusual conditions, known as events, and then manage the events based on specifications defined by the database administrator. Events can trigger a job to take preventative or corrective action to keep a system available and to collect information for later analysis. If events are serious enough, Map is notified to change the visual signal flags on the graphical display. EMS can even send mail or use pagers to notify individuals of events.
Like Job, EMS uses the communications daemon on the local client and remote intelligent agents on each system to monitor and respond to events. The intelligent agents actually monitor system resources, so the events are managed 24 hours a day without the direct participation of the Enterprise Manager console. Without Oracle Intelligent Agent installed and configured, Job is not usable.
To begin monitoring a remote resource for a particular event, the event must be registered in EMS. A variety of predefined events come ready to configure and register. The process to begin monitoring is best explained using a simple example. To monitor the availability of a remote listener, start by selecting Event, Create Event Set from the Enterprise Manager menu bar. The resulting window contains three tabs: General, Events, and Parameters.
Starting with General, give the event a name and description and select the service. To monitor a listener, the service type should be Listener. Next, move to the Events tab. For other service types such as Database, there are many events available to create an event set if the Performance Pack is implemented (see Figure 9.6), but for a listener, EMS only monitors whether