Manual Recovery

You can use various techniques to manually recover individual subcomponents:

• Recovering the Domain Administration Server

• Recovering Node Agents and Server Instances

• Recovering Message Queue

Recovering the Domain Administration Server

Loss of the Domain Administration Server (DAS) affects only administration. Communications Server clusters and applications will continue to run as before, even if the DAS is not reachable

Use any of the following methods to recover the DAS:

• Run asadmin backup commands periodically, so you have periodic snapshots. After a hardware failure, install App Server on a new machine, with the same network identity and run asadmin restore from the back up created earlier. For more information, see Recreating the Domain Administration Server.

• Put the domain installation and configuration on a shared and robust file system (NFS for example). If the primary DAS machine fails, a second machine is brought up with the same IP address and will take over with manual intervention or user supplied automation. Sun cluster uses a similar approach for making DAS fault-tolerant.

• Zip the Communications Server installation and domain root directory. Restore it on the new machine, assigning it the same network identity. This may be the simplest approach if you are using the file-based installation.

• Restore from DAS backup. See the AS8.1 UR2 patch 4 instructions

Recovering Node Agents and Server Instances

There are two methods for recovering node agents and sever instances.

Keep a backup zip file. There are no explicit commands to back up the node agent and server instances. Simply create a zip file with the contents of the node agents directory. After failure, unzip the saved backup on a new machine with same host name and IP address. Use the same install directory location, OS, and so on. A file-based install, package-based install, or restored backup image must be present on the machine.

Manual recovery. You must use a new host with the same IP address.

1. Install the Communications Server with node agent on the machine.

2. Recreate the node agents. You do not need to create any server instances.

3. Synchronization will copy and update the configuration and data from the DAS.

Recovering Message Queue

Message Queue (MQ) configurations and resources are stored in the DAS and can be synchronized to the instances. Any other data and configuration information is in the MQ directories, typically under /var/imq, so backup and restore these directories as required. The new machine must already contain the MQ installation. Be sure to start the MQ brokers as before when you restore a machine.