6 Configuring Server Pools and Oracle Enterprise Manager Database Control

6.1.1 Oracle RAC One Node and Server Pools

Note the following about Oracle RAC One Node and server pools:

• Oracle RAC One Node runs only in one server pool. This server pool is treated the same as any other server pool.

• Online relocation of an Oracle RAC One Node database instances permits planned migrations of an Oracle RAC One Node database from one node to another node. Relocations must always be within a server pool.

• With WLM integration, online relocation of Oracle RAC One Node database instance operations do not take a server away from a server pool with its importance set to a lower value, because the target server must already be in the server pool, or in Free.

• An Oracle RAC One Node database can be a Data Guard physical standby.

6.1.2 Policy-Based Cluster and Capacity Management

Using policy-based server pool management, database administrators define resource requirements for the workload, including the following:

• Defining the number of servers or instances preferred for the application. Oracle Clusterware automatically allocates resources up to the number specified, so long as they are physically available, and relocates a resource to another node as necessary.

• Defining the number of instances required to support the application.

Resources are no longer defined as belonging to a specific instance or node. Instead, the priority of resource requirements is defined.

6.2.1 Understanding Using EMCA with Oracle RAC

Each EMCA command can be used in Oracle RAC environments, and certain commands are only applicable in cluster configurations. To perform EMCA cluster commands, use the -cluster flag that is available in almost every EMCA operational mode.

When you use EMCA to configure Database Control for Oracle RAC, you configure the Database Control for each instance in the cluster. However, by default, the Database Control Console will only start on the local node. On every other node of the cluster, only the Enterprise Manager agent will start. This is because the Database Control Console opens a number of connections to the database. If an instance of the console is running on every host in the cluster, then you can easily exceed the maximum number of permitted open connections on a 32-node or 64-node environment.

When Database Control Console is started on the local node, on every other node, the commands emctl start dbconsole and emctl stop dbconsole only start and stop the agent. Each of the remote agents upload their respective data to the console running on the local node, where you can monitor and manage all the targets in the cluster. On each instance of the Oracle RAC database, the following subdirectories will be created, where nodename is the name of a node in the cluster, and DBUniqueName is the database unique name.

$ORACLE_HOME/nodename_DBUniqueName
$ORACLE_HOME/nodename_DBUniqueName

However, note that if you upgrade an existing Oracle RAC 10g release 1 database configured with Database Control to the current release, then the existing Database Control configuration is retained. The existing Database Control has a Database Console running on each cluster node. The console will still be started on each individual node.

If you want to modify the existing configuration, then use the following command:

emca -reconfig dbcontrol –cluster –EM_NODE nodename -EM_NODE_LIST NODE_list

where nodename is the public name of the node, and NODE_list is a comma-deliminated list of nodes. This command reconfigures the current Database Control setup, and performs the following actions in sequence:

1. Starts a Database Control Console on nodename, if one has not been started yet.

2. Redirects the agents monitoring the database instances in NODE_list so that they upload their data to the console running on nodename. Also, agents monitoring database instances on nodename will also upload their data to the local console. Note that if you do not enter the command options -EM_NODE or -EM_NODE_LIST at the command line, you will be prompted for them.

-EM_NODE defaults to the local node if not specified when prompted. If not specified, -EM_NODE_LIST defaults to all nodes where the database is configured.

Use this command to start the console on more than one node. For instance, on an eight-node cluster with nodes node1, node2, node3, node4, node5, node6, node7, and node8, you can run the following commands in succession:

$ emca -reconfig dbcontrol –cluster –EM_NODE node1 -EM_NODE_LIST node2,node3,node4
$ emca -reconfig dbcontrol –cluster –EM_NODE node5 -EM_NODE_LIST node6,node7,node8

In this scenario, there are two Database Control consoles running, one on node1 and the other on node5. From either of these consoles, you can manage and monitor all of the targets in the cluster.

For information about the current cluster configuration, you can run the following command:

$ emca -displayConfig dbcontrol –cluster

To configure Enterprise Manager for a newly added node of a cluster, use the following command:

$ emca -addNode db

On policy managed databases, another common operation is the addition and deletion of cluster nodes. After you add a new node, you can run EMCA to configure Database Control or central agent management for that node using the command emca -addNode db. Running EMCA only configures Enterprise Manager so that you can manage the instance in a way that is consistent with the rest of the cluster database instances.

When configuring Enterprise Manager for a new node, run the EMCA command only after you have added the node. Also, run the command from a node in the cluster that already has Enterprise Manager configured for it, because the Enterprise Manager configuration settings on the existing node are propagated to the new node when you run the command. Because the -addNode option can be used only in an Oracle RAC environment, you do not need to use the -cluster option on the command line.

After running the command emca -addNode db, enter the node name and database unique name for the node and database. For example:

Node name: node2
Database Unique Name: EM102

To deconfigure Enterprise Manager for a specific node you are deleting from the cluster, log into a different node from the node that you plan to delete, and use the command emca -deleteNode db. Running this command removes the Enterprise Manager configuration so that you will no longer be able to manage the instance with Enterprise Manager on that node. Ensure that you run the EMCA command before you delete the cluster node. Because this option can be used only in an Oracle RAC environment, you do not need to use the -cluster option on the command line.

6.2.2 Configuring Database Control During Installation

If you create a database while installing Oracle RAC 11g release 2 (11.2), you have the option of configuring your database so it can be managed by Oracle Enterprise Manager 10g Grid Control Console or by Oracle Enterprise Manager 11g Database Control Console.

To select Grid Control Console as your management option, the Oracle Management Service must be installed on a network host. In addition, the Oracle Management Agent must be installed on the host where you are installing the database. Otherwise, the Grid Control Console option is unavailable and you must instead manage your database with Database Control.

For most of the Oracle RAC 11g release 2 (11.2) installation types, you must choose either Database Control or Grid Control as your management option when you create a database during the installation.

However, if you create a database using one of the following methods, then you can choose not to configure Database Control:

• Choosing the Advanced database configuration option during an Enterprise or Standard Edition installation

• Running Database Configuration Assistant (DBCA) after the installation

If you do not configure Database Control during the Oracle RAC 11g release 2 (11.2) installation, no hostname_dbuniquename directory is created in the resulting Oracle home directory.

6.2.3 Configuring Database Control with DBCA

The primary method for configuring an existing Oracle Database 11g release 2 (11.2) database so it can be managed with Database Control is to use DBCA. You can use DBCA to create a new database or to reconfigure an existing database.

To use DBCA to reconfigure your database so it can be managed with Database Control:

1. Log into the database host as a member of the administrative group that is authorized to install Oracle software and create and run the database.

2. Start DBCA and change directory to the ORACLE_HOME/bin directory and enter the following command:

   $ ./dbca
   

   The DBCA Welcome page appears.

3. Advance to the Operations page and select Configure Database Options.

4. Advance to the Database page and select the database you want to configure.

5. Advance to the Management Options page and select the following options:

   • Configure the Database with Enterprise Manager

   • Use Database Control for Database Management

6. Optionally, select the options for enabling e-mail notifications and enabling daily backups.

   For more information about Enterprise Manager notifications and daily backups, click Help on the Management Options page.

7. Advance until the Finish button is available.

8. Click Finish to reconfigure the database so it uses Database Control.

   After DBCA reconfigures the database, a new subdirectory appears in the Oracle home. This directory is named using the following format and contains Database Control configuration and state files specific to the database you just configured:

   hostname_dbuniquename
   

   Note that for cluster databases, the directories are named nodename_dbuniquename. For example:

   mycluster1.example.com_myNewDB
   

6.2.4 Configuring Database Control After Installation Using EMCA

When you use DBCA to configure Oracle RAC 11g release 2 (11.2), DBCA provides a graphical user interface to help you select Database Control options and to configure other aspects of your database. However, if you want to use the operating system command line to configure Database Control, then you can use the Enterprise Manager Configuration Assistant (EMCA).

To configure Database Control with EMCA:

1. Set the ORACLE_HOME environment variable to identify the Oracle home for the database you want to manage:

2. Change directory to the ORACLE_HOME/bin directory.

3. Start EMCA by entering the following command with any of the optional command-line arguments shown in Table 6-1:

   $ ./emca 
   

   Depending upon the arguments you include on the EMCA command line, EMCA prompts you for the information required to configure Database Control.

   For example, enter the following command to configure Database Control so it will perform automatic daily backups of your database:

   $ ./emca -config dbcontrol db -backup
   

EMCA commands are of the form:

emca [operation] [mode] [flags] [parameters]

emca -config dbcontrol db -repos create

Table 6-1 describes the valid execution operations and modes, and lists the optional parameters in brackets. Table 6-2 discusses the flags and their behavior, while Table 6-3 defines the optional parameters in detail. EMCA parameters are of the form [-parameterName parameterValue]. Multiple parameters can be used in combination at the command line.

6.2.5 Using an Input File for EMCA Parameters

Instead of answering a series of prompts when you run EMCA, you can use the -respFile argument to specify an input file. The input file that you create must be in a format similar to the following example:

PORT=1521
SID=DB
DBSNMP_PWD=xpE234D
SYSMAN_PWD=KDOdk432

After you create an EMCA input file, you can use it on the command line as follows:

$ ./emca -config dbcontrol db -respFile input_file_path

For example, to configure the Database Control to perform daily backups and create the Database Control Management Repository, create an input file similar to the one shown in the following example:

PORT=1521
SID=DB
DBSNMP_PWD=dow3l224
SYSMAN_PWD=squN3243
HOST_USER=johnson
HOST_USER_PWD=diTf32of
SYS_PWD=qlKj4352
BACKUP_SCHEDULE=06:30

When you have created the input file, then enter the following command at the operating system prompt:

$ ./emca -config dbcontrol db -repos create -backup -respFile input_file_path

6.2.6 Specifying the Ports Used by Database Control

When you initially install Oracle RAC 11g release 2 (11.2) or configure Database Control with EMCA, Database Control uses a set of default system ports. For example, by default, you access Database Control using port 1158 in 11g Release 2, as in:

http://host.domain:1158/em

This is the default port assigned to Database Control by the Internet Assigned Numbers Authority (IANA). Likewise, the default Database Control Agent port, as assigned by the IANA, is 3938.

To use ports other than the default ports, use the following EMCA command-line arguments when you initially configure the Database Control with EMCA. Alternatively, you can explicitly assign ports after configuring Database Control using the following command:

emca -reconfig ports [-cluster]

The following list summarizes the EMCA command-line arguments that control the standard Database Control port assignments:

• -DBCONTROL_HTTP_PORT port_number

  This port number is used in the Database Control Console URL. For example, if you set this port to 5570, you can then display the Database Control Console using the following URL:

  http://host.domain:5570/em
  

• -RMI_PORT port_number

  This port number is used by the Remote Method Invocation (RMI) system, which is part of the J2EE software required by Database Control. The default port can be changed if you want to configure a specific port for Database Console. When a port other than the default port (1521) is used, use the -RMI_PORT or -JMS_PORT options along with the emca reconfig command.

• -JMS_PORT port_number

  This port is used by the OC4J Java Message Service (JMS), which is part of the J2EE software required by Database Control. The default port can be changed if you want to configure a specific port for Database Console. When a port other than the default port (1521) is used, use the -RMI_PORT or -JMS_PORT options along with the emca reconfig command.

• -AGENT_PORT port_number

  This port is used by the Database Control Management Agent, which is monitoring and administering the database for the Database Control.

6.2.7 EMCA Troubleshooting Tips

The following section describes some troubleshooting tips to consider when using EMCA to configure the Database Control:

• Using EMCA After Changing the Database Listener Port

• Upgrading 11g Release 2 Grid Control Agents

• Using EMCA When Database Host Name or IP Address Changes

• Using EMCA When the TNS Configuration Is Changed

emca -deconfig dbcontrol db -repos drop
emca -config dbcontrol db -repos create

emca -deconfig dbcontrol db
emca -config dbcontrol db -repos recreate

emca -config dbcontrol db