Donald K. Burleson    Oracle Utilities Tips

The OEMCTL Utility

The next monitoring utility that will be explained is used as part of Oracle Enterprise Manager (OEM) to provide many shared services for managing databases. OEM is the database management solution provided by Oracle Corporation. The OEMCTL utility manages the Oracle Management Server (OMS) used by OEM.

The OMS manages back-end application logic and stores information in the OEM repository. The functionality provided by the management server includes events, jobs, data sharing, and reports. The OMS serves as the middle tier between the management pack GUIs and the databases being managed. Multiple OMSs can exist in order to evenly distribute heavy workloads across this middle tier, although only one OMS can exist per node.

The repository used by OMS is simply a set of tables in a particular instance that support the management pack (Change, Diagnostics, Tuning) components of OEM.

Many commands are available from the oemctl executable at the OS level that help the DBA to manage the OMS. The following command will start the OMS:

oemctl start oms

If already running, the feedback from the command will respond, “The requested service has already been started.”

The OMS is a Java application and when started, the Java Runtime (JRE) will be loaded into memory and consume approximately 40MB of RAM.

The method used to see if an OMS server is up and running is similar to the method in which a network administrator would check for TCP/IP communication to a remote host – ping.

oemctl ping oms

The ping command reports “the management server is running”. To get a more detailed status of the OMS, the status command can be executed. This command, along with the stop command, requires the OMS Administrator’s username and password in order to work. Optionally, the host name of the machine containing the OMS process can be specified if not the local machine. The default OMS Administrator username is password is sysman/oem_temp.

oemctl status oms <EM Username>/<EM Password>[@<OMS-hostname>]

This command requires the OMS administrator username and password. If not supplied, a Java application window will pop up and prompt for the username and password, as shown in Figure 5.3 below. Therefore, it is critical that the machine that initiates the command supports Java, otherwise the command will hang. For instance, if an attempt is made to obtain the status of the OMS by telnetting from a Windows machine to a UNIX box, the command will hang because the Java GUI application is unable to load. Again, this only applies when not specifying the username and password on the command line.


The result of the oemctl status command is shown below. Note the additional information that status provides over the ping command.

The Oracle Management Server on host [moorepc] is functioning properly.

The server has been up for 0 00:02:45.406

Target database session count: 0 (session sharing is off)
Operations queued for processing: 1
Number of OMS systems in domain: 1 (moorepc)
Number of administrators logged in: 1
Repository session pool depth: 15
Repository session count: 7 in-use and 4 available, pool
efficiency: 35%
 

To learn more about these techniques, see the book "Advanced Oracle Utilities: The Definitive Reference". 

You can buy it directly from the publisher and get instant access to the code depot of utilities scripts.