Configuring a Standby Mobility XE Warehouse

Technical Note 2130

Last Reviewed 18-Jun-2008
Applies To
Mobility XE
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Summary

This tech note describes the procedure for setting up a second, standby warehouse to act as a read-only backup in the event that your primary warehouse is temporarily unavailable.

Background

The Mobility warehouse uses Sun ONE Directory Server v5.2. Sun's Directory Server allows you to extend reliability by installing active backup servers that are mirrors of the primary server. When using this configuration, the first Mobility XE warehouse is referred to as the primary warehouse, and the second one is referred to as a standby warehouse, since it provides read-only services when the primary warehouse is unavailable.

Deploying Primary and Standby Warehouse Servers

When you deploy NetMotion Mobility XE, you configure one warehouse to be the primary directory server that all Mobility XE servers point to for reading and writing settings. You can then deploy one or more additional warehouses as standby warehouse servers for your server pool. As changes are made to the primary warehouse, they are automatically and continuously sent to the standby warehouse(s).

If the primary warehouse becomes unavailable, the Mobility server(s) will try to establish a connection with one of the standby warehouses. (Note: this may take a few minutes.) Once that connection is established, the standby warehouse will take over as a read-only warehouse, which means registered clients can maintain or establish connections, but administrators cannot make configuration changes and brand-new clients cannot register and establish sessions.

When the primary warehouse comes back on line, the Mobility XE servers will automatically re-establish the connection with the primary warehouse.

Setting up a Standby Warehouse

The procedure below explains how to configure a standby warehouse to perform as a read-only backup if your primary warehouse fails or is temporarily unavailable. The procedure is described in the following sections:

• Preparing the standby warehouse to receive updates

• Enabling Replication on the primary warehouse

• Specifying the standby warehouse from the primary warehouse

• Initializing replication

Preparing the Standby Warehouse to Receive Updates

1. Using NetMotion Mobility XE Setup, perform a warehouse-only install on the computer you want to use as a standby warehouse server. Make sure you follow the guidelines below.

   • It is strongly recommended that you use the same user ID and password for this Sun ONE Console that you use to access the Sun ONE Console of your primary warehouse. If for any reason it is not possible to use the same credentials, then take special note of the password you create; you will want to use it again later in this procedure.

     
     

   • If the warehouse is installed from version 8.0 or later, Setup will prompt you for the base DN (Distinguished Name). The base DN is based on the workgroup or domain where the warehouse computer resides. When you install a standby warehouse in the same domain or workgroup as the primary, the default base DN will be the same and you should click Next. However, if you install a standby warehouse in a different domain or workgroup, you must change the proposed name to match the base DN of the primary warehouse. Replication will not occur unless these names are identical. (Note: Because the warehouse does not interact with the domain, changing the base DN will not affect its functionality or performance.)

     
     

     If you are unsure of the Base DN of your primary warehouse, you can find it on the second line of its LDIF file. It will look something like ʺdn: o=NetMotion,dc=nmwco,dc=comʺ. See tech note 2129 for instructions on obtaining an LDIF file from your primary warehouse.

   
   

2. Open the Sun ONE Server Console (on the Start menu, click Programs, Sun ONE Server Products, Sun ONE Server Console 5.2), and log on with the user ID and password you created during warehouse setup.

3. On the Servers and Applications tab, expand the tree until you see your Directory Server listing. Select your server, and then click Open.

4. On the Configuration tab, expand the Data node, and then expand the "o=NetMotion,..." node. Select Replication (Disabled), and then click Enable replication.

5. On the Enabling Replication dialog box, select Consumer Replica, and then click Next.

6. Enter a password (it is strongly recommended that you use the same password you created for the Sun ONE Server Console) and then click Next. If for any reason it is not possible to use the same password, then take special note of the one you create; you will need to use it again later in this procedure when you are specifying the standby warehouse (next).

7. A dialog box appears stating that the consumer replica server is ready to receive replication updates. Click Close, and then exit the Sun ONE Server Console.

Preparing the Primary Warehouse to Send Updates

Enabling Replication

1. On the computer running your primary warehouse, open the Sun ONE Server console. (On the Start menu, click Programs, Sun ONE Server Products, Sun ONE Server Console 5.2.)

2. On the Servers and Applications tab, expand the tree until you see your Directory Server listing. Select your server, and then click Open.

3. On the Configuration tab, expand the Data node, and then expand the "o=NetMotion,..." node. Select Replication (Disabled), and then click Enable replication.

4. On the Enabling Replication dialog box, select Master Replica, and then click Next.

5. Enter '1' as the ID number for the master replica, and then click Next.

6. For the change log file, accept the default location or specify a new one, then click Next.

7. Enter a password (it is strongly recommended that you use the same password you created for the Sun ONE Server Console) and then click Next.

8. A message box will appear indicating that replication is now enabled. Click Close.

Specifying the Standby Warehouse

1. On the Replication screen, click New on the right side of the panel.

2. In the "Send updates to" field, click Other. Enter the IP address (or fully-qualified domain name) of your standby warehouse, and then enter the port number (389 is the default).

3. In the Authentication field, accept the default DN, and then enter the password you used to configure your standby warehouse in the section above. Click OK.

4. Click Yes on the Confirmation dialog box, and then click OK when you receive the Information Message confirming the connection between the two servers.

Initializing Replication

1. Under Defined replication agreements, select your standby warehouse. Click Action, and then select Initialize remote replica.

2. Click Yes on the Confirmation dialog box.

3. After initialization is complete, restart the standby warehouse:

   1. On the computer running your standby warehouse, open the Sun ONE Server console. (On the Start menu, click Programs, Sun ONE Server Products, Sun ONE Server Console 5.2.)

   2. On the Servers and Applications tab, expand the tree until you see your Directory Server listing. Select your server, and then click Open.

   3. On the Tasks tab, click Restart Directory Server.

For Mobility XE version 6.50 and higher, this procedure is now complete.

Version 6.0x only:

4. After the warehouse has restarted, reboot your Mobility XE servers. (If the warehouse is colocated with the Mobility server, just one reboot is necessary.) A version 6.0x Mobility server only reads standby warehouse information at startup and will not know about the new standby warehouse until it reboots. The reboot can be done at any time, however. The Mobility server will continue to operate, and replication will continue to function, until you reboot the server at a convenient time.

Using a Standby Warehouse

The standby warehouse receives updates automatically from the primary warehouse. If the primary warehouse is unavailable for a period of time, the standby warehouse takes over to maintain connections until you bring the primary warehouse back online.

Diagnosing Warehouse Failure

• If the Mobility server cannot contact the primary warehouse, the event log will record an error, and the Mobility Console will display a message indicating that the Warehouse is not available.

• If the Mobility server or server pool switches to a standby warehouse, the event log will record an error, and the Mobility Console will display the new warehouse address on the About page.

Recovering Warehouse Settings

If the primary warehouse cannot be brought back online (for example, due to a hardware failure), you can promote the standby warehouse to take over as the primary warehouse with full read-write capabilities, or you can export the settings from your standby warehouse and import them to a replacement primary warehouse.

For detailed information on warehouse recovery options, see technical note 2135.

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