After you have created a hierarchy, you will want to extend that hierarchy to another server in the cluster. There are three possible scenarios to extend your resource instance from the template server to a target server. The first scenario is when you Continue from creating the resource into extending that resource to another server. The second scenario is when you enter the Extend Resource Hierarchy task from the edit menu as shown below. The third scenario is when you right-click on an unextended hierarchy in either the left or right pane. Each scenario takes you through the same dialog boxes (with a few exceptions, which are clearly detailed below).
- If you are entering the Extend wizard from the LifeKeeper GUI menu, select Edit, then Resource. From the drop‑down menu, select Extend Resource Hierarchy. This will launch the Extend Resource Hierarchy wizard.
- The first dialog box to appear will ask you select the Template Server where your MySQL resource hierarchy is currently in service. It is important to remember that the Template Server you select now and the Tag to Extend that you select in the next dialog box represent an in service resource hierarchy. An error message will appear if you select a resource tag that is not in service on the template server you selected. The drop‑down box in this dialog provides the names of all the servers in your cluster.
Note: If you are entering the Extend Resource Hierarchy task immediately following the creation of a MySQL resource hierarchy, this dialog box will not appear, since the wizard has already identified the template server in the create stage. This is also the case when you right‑click either the MySQL resource icon in the left pane or right‑click on the MySQL resource box in the right pane the of the GUI window and choose Extend Resource Hierarchy.
It should be noted that if you click Cancel at any time during the sequence of extending your hierarchy, LifeKeeper will cancel the extension process to that particular server. However, if you have already extended the resource to another server, that instance will continue to be in effect until you specifically unextend it.
For example, let us say you have created your resource on Server 1 and extended that resource to Server 2. In the middle of extending the same resource to Server 3, you change your mind and click Cancel inside one of the dialog boxes. This will cancel only your action to extend the resource to Server 3, not the extension you created to Server 2. If you want to remove Server 2 from this hierarchy, you must unextend the resource from Server 2.
Click Next to proceed to the next dialog box.
- Select the Tag to Extend. This is the name of the MySQL instance you wish to extend from the template server to the target server. The wizard will list in the drop‑down menu all the resources that you have created on the template server, which you selected in the previous dialog box.
Note: Once again, if you are entering the Extend Resource Hierarchy task immediately following the creation of a MySQL resource hierarchy, this dialog box will not appear, since the wizard has already identified the tag name of your MySQL resource in the create stage. This is also the case when you right‑click either the MySQL resource icon in the left hand pane or on the MySQL resource box in the right hand pane of the GUI window and choose Extend Resource Hierarchy.
- Select the Target Server where you are extending your MySQL resource hierarchy. The drop‑down box provides the names of the servers in your cluster that are not already in the selected hierarchy.
- Select the Switchback Type. This dictates how the MySQL instance will be switched back to this server when it comes back into service after a failover to the backup server. You can choose either intelligent or automatic. Intelligent switchback requires administrative intervention to switch the instance back to the primary/original server. Automatic switchback means the switchback will occur as soon as the primary server comes back online and reestablishes LifeKeeper communication paths.
The switchback type can be changed later, if desired, from the General tab of the Resource Properties dialog box.
- Select or enter a Template Priority. This is the priority for the MySQL hierarchy on the server where it is currently in service. Any unused priority value from 1 to 999 is valid, where a lower number means a higher priority (1=highest). The extend process will reject any priority for this hierarchy that is already in use by another system. The default value is recommended. Note: This selection will appear only for the initial extend of the hierarchy.
- Select or enter the Target Priority. This is the priority for the new extended MySQL hierarchy relative to equivalent hierarchies on other servers. Any unused priority value from 1 to 999 is valid, indicating a server’s priority in the cascading failover sequence for the resource. A lower number means a higher priority (1=highest). Note that LifeKeeper assigns the number “1” to the server on which the hierarchy is created by default. The priorities need not be consecutive, but no two servers can have the same priority for a given resource.
- An information box will appear explaining that LifeKeeper has successfully checked your environment and that all the requirements for extending this MySQL resource have been met. If there were some requirements that had not been met, LifeKeeper would not allow you to select the Next button, and the Back button would be enabled.
If you click Back, you can make changes to your resource extension according to any error messages that may appear in the information box.
If you click Cancel now, you will need to come back and extend your MySQL resource hierarchy to another server at some other time to put it under LifeKeeper protection.
When you click Next, LifeKeeper will launch you into the Extend Resource Hierarchy configuration task.
- This dialog box is for information purposes only. You cannot change the Location of my.cnf that appears in the box. The MySQL instance acquired the location information from its configuration file.
- Select or enter the Location of MySQL executables.This is the full path name of the binaries used to start and monitor the MySQL database server daemon.
- Select or enter the Database Tag. This is a tag name given to the MySQL hierarchy. You can select the default or enter your own tag name.
- An information box will appear verifying that the extension is being performed.
Click Next Server if you want to extend the same MySQL resource instance to another server in your cluster. This will repeat the Extend Resource Hierarchy operation.
If you click Finish, LifeKeeper will verify that the extension of the MySQL resource was completed successfully.
- If you clicked Finish, the following screen appears.
- Click Done in the last dialog box to exit.
Note: Be sure to test the functionality of the new instance on both servers.