Switchover and failover operations are handled by the scripts nms-ha-switchover and nms-ha-failover, respectively. These scripts are run at the NMS site that is to become primary. They require prior configuration by the nms-ha-config script. Configuration is stored in the file $NMS_HOME/etc/nms_sites.cfg and credentials necessary to use Oracle Data Guard are stored in the Oracle Wallet.

nms-ha-switchover performs a Switchover operation. It is run from the command line on the NMS site which is to become primary. After validating that NMS and the database are ready for a switchover, it performs the following actions:

Note: Run nms-ha-switchover -h for full usage information.

nms-ha-failover performs a Failover operation. It is run from the command line on the NMS site that is to become primary. After NMS and the database are ready for a failover, it performs the following actions.

1. Perform an Oracle Data Guard Failover to make the database corresponding to site where this script runs Primary

2. Run nms-sync-site to sync data directory files from the current primary site if possible.

3. Update the NMS database to mark the current site as primary.

4. Start services and WebLogic.

Note: Run nms-ha-failover -h for full usage information.

nms-ha-config creates or updates the configuration necessary to run the nms-ha-switchover and nms-ha-failover scripts. It has several subcommands. Run “nms‑ha‑config -h” for a script overview or “nms‑ha‑config <subcommand> -h” for details for each subcommand. For initial high availability configuration, run “nms‑ha‑config init” to generate $NMS_HOME/etc/nms_sites.cfg and local entries in the Oracle Wallet. Then copy this file to each NMS environment at each NMS site and run the following command on each environment to add entries to the Oracle Wallet:

Perform initial high availability configuration

This prompts for the following information and saves nms_sites.cfg.

 

-h, --help: show this help message and exit.

--connect: CONNECT Data Guard static connect identifier

usage: nms-ha-config add [-h] site

Add a new NMS site to configuration. This prompts for the hostname where NMS Services run positional arguments:

site: Name of site to add

-h, --help: show this help message and exit

Update configuration for an NMS site already in config file

The values for the passed in parameters will be changed. If the --wallet parameter is used, then you will be prompted for updating the information in the Oracle Wallet.

site: Site to update

 

-h, --help: show this help message and exit

--hostname HOSTNAME: Hostname for NMS services

--dbname DBNAME: Database name in Data Guard configuration

--connect CONNECT: Data Guard static connect identifier

--wallet: Update Oracle wallet

usage: nms-ha-config remove [-h] site [site ...]

Remove an NMS site from configuration positional arguments:

site: Site to remove

-h, --help: Show this help message and exit.

Failover patching is a mechanism for installing patches with almost zero downtime. See Steps to Deploy a Patch Bundle using Failover Patching in the System Installation chapter of the Oracle Utilities Network Management System Installation Guide.