La distribución normal como medida de los mercados financieros.

switchover topology

During a scheduled outage of the production site, performs the switchover operation from the production site to the standby site.

Format

switchover topology to <standby_topology_host>[:<port>] [using policy <file>]

Parameters

standby_topology_host

Name of the standby host system. This parameter is required because it directs the coordinating OracleAS Guard server instance to discover the instances that make up the standby site. This host system must be a member of the standby topology. port

The port number of the standby host system for the OracleAS Guard server in its Oracle home.

using policy <file>

Full path and file specification for the XML policy file.

Usage Notes

On the primary infrastructure system, make sure the emagent process is stopped. Otherwise, you may run into the following error when doing a switchover operation because the emagent process has a connection to the database:

prodinfra: -->ASG_DGA-13051: Error performing a physical standby switchover. prodinfra: -->ASG_DGA-13052: The primary database is not in the proper state to perform a switchover. State is "SESSIONS ACTIVE"

On UNIX systems, to stop the emagent process, stop the Application Server Control, which is called iasconsole, as follows:

> <ORACLE_HOME>/bin/emctl stop iasconsole

On UNIX systems, to check to see if there is an emagent process running, do the following:

> ps -ef | grep emagent

On UNIX systems, if after performing the stop iasconsole operation, the emagent process is still running, get its process ID (PID) as determined from the previous ps command and stop it as follows:

> kill -9 <emagent-pid>

On Windows systems, open the Services control panel. Locate the OracleAS10gASControl service and stop this service.

Make sure OracleAS Infrastructure database is running on the primary topology before performing a switchover operation. Also, the OracleAS Infrastructure database information must be set by using the set primary database asgctl command.

The global DNS names are used to direct the switchover. This will be different than the HA naming utilized in the OracleAS Disaster Recovery environment. The discovery

mechanism automatically maps the topology to the corresponding peer, based off local name resolution.

As part of the OracleAS Guard switchover operation, an implicit sync topology operation is performed to make sure the topologies are identical. In addition OPMN automatically starts the OracleAS Guard server on the "new" standby Infrastructure node and this server will run indefinitely, and in turn, starts the OracleAS Guard server on the other nodes in the "new" standby topology and each of these is a transient server.

For the switchover policy file, by default the success requirement attribute is set to optional for all instances (middle tier and OracleAS Metadata Repository) and mandatory for the Oracle Internet Directory home.

During a switchover operation, the opmn.xml file is copied from the primary site to the standby site. For this reason, the value of the TMP variable must be defined the same in the opmn.xml file on both the primary and standby sites, otherwise this switchover operation will fail with a message that it could not find a directory. Therefore, make sure the TMP variable is defined identically and resolves to the same directory structure on both sites before attempting a switchover operation.

When performing a switchover operation from a primary site with two Oracle Identity Management instances running (im.machineA.us.oracle.com and

im.machineB.us.oracle.com) to a standby site representing an asymmetric topology with only one Oracle Identity Management instance running

(im.machineA.us.oracle.com), meaning that the other node

(im.machineB.us.oracle.com) is to be ignored on the switchover site, the system administrator must not only edit the switchover_policy.xml policy file to indicate that this other node is to be set to Ignore, but the system administrator must also shut down all processes running on that node (im.machineB.us.oracle.com) in order for the switchover operation to be successful.

When performing a switchover operation from a primary site with two middle tiers, for example core1 and core2 instances registered in the Oracle Internet Directory, to a standby site representing an asymmetric topology with only one middle tier core1, the standby site actually has both core1 and core1 middle tiers registered in the Oracle Internet Directory. The switchover_policy.xml policy file is edited to ignore the core2 middle tier that does not exist on the standby site during the switchover operation. However, it should be noted that the Oracle Internet Directory, which is stored in an Oracle database, is identical for both the production site topology and the standby site topology and therefore a core2 middle tier is also shown to be registered in the Oracle Internet Directory on the standby site topology. For this reason, you cannot install to that standby site topology the same core2 middle tier with the hope of making this into a symmetric topology again. This is a strict limitation for switchover operations using asymmetric standby topologies.

When the discover topology command is issued following a switchover operation and the asymmetric standby site topology originally had one or more fewer middle tiers (for example, instA and instB) than there were in the original production site topology (instA, instB, and instC), a warning error message displays for each missing instance of a middle tier (instC, in this case). This warning error message is expected and can be ignored. When a discover topology to command is issued following a switchover operation, OracleAS Server Guard reads the Oracle Internet Directory information, which is an exact copy of the original primary site Oracle Internet Directory information on this new primary site (former standby site). Because this Oracle Internet Directory information is identical to the original primary site Oracle Internet Directory information, when OracleAS Server Guard visits the host/home of each

switchover topology

instance of these middle tiers to verify their existence, it finds that some do not exist, and issues the warning.

See Section 6.1, "Information Common to OracleAS Guard asgctl Commands" and Section 6.2, "Information Specific to a Small Set of OracleAS Guard Commands" for more information.

Example

The following example performs a switchover operation to a standby site known by DNS as standbyinfra.

ASGCTL> connect asg prodinfra ias_admin/adminpwd Successfully connected to prodinfra:7890

ASGCTL> set primary database sys/testpwd@asdb ASGCTL> switchover topology to standbyinfra Generating default policy for this operation prodinfra:7890

Switchover each instance in the topology to standby topology prodinfra:7890 (home /private1/OraHome2/asr1012)

Connecting to the primary database asdb.us.oracle.com

Gathering information from the primary database asdb.us.oracle.com Shutting down each instance in the topology

. . .

prodinfra:7890

HA directory exists for instance asr1012.infra.us.oracle.com asmid2:7890

HA directory exists for instance asmid2.asmid2.us.oracle.com asmid1:7890

HA directory exists for instance asmid1.asmid1.us.oracle.com standbyinfra:7890

HA directory exists for instance asr1012.infra.us.oracle.com asmid2:7890

HA directory exists for instance asmid2.asmid2.us.oracle.com asmid1:7890

HA directory exists for instance asmid1.asmid1.us.oracle.com prodinfra:7890

Verifying that the topology is symmetrical in both primary and standby configuration ASGCTL>

# Command to use if you are using a policy file