Adding a Logical Cluster

Each logical cluster has a set of instances on which it runs, and can have a set of instances to which it fails over.

1. In the left pane of the Administration Console, expand ASE Servers > Cluster Management, then select Logical Cluster.
2. Click the drop-down arrow and select New.
3. Select the shared cluster to which to add the logical cluster.
4. Assign a name that is representative of the job the logical cluster will perform, such as SalesLC.
5. Click Add to select the instances you want to add to the logical cluster. These instances are considered "base" instances.
   You can remove an instance from this list by clicking Remove.
6. In the Failovers screen, select Add to choose the failover server instances on which the logical cluster runs if one or more of the base instances fail. Any instance in the physical cluster can be a failover resource.
7. Select the group number for the failover instances. The failover group lets you specify preference and order in which failover instances are used. Lower-numbered groups are used first.
8. Click Add to add routed applications, logins, or aliases.
   Routing rules allow you to specify specific applications, logins, and aliases to which the logical cluster connects. See the Cluster Users Guide for more information about routing. Add additional routes by selecting:

   • Application Route – specify the name of the application in the Add Application Route screen.
   • Alias Route – specify the alias name in the Add Alias Route screen.
   • Login Route – select the login name from the list in the Add Login Route screen (hold the Ctrl key to select multiple names).

   You can drop a listed route by selecting the route name and clicking Remove.

9. On the Load Profile screen, click Change to select a load profile to assign to the logical cluster.
   The Cluster Edition offers two system load profiles: sybase_profile_oltp for OLTP environments and sybase_profile_dss for DSS environments. You cannot modify or delete system load profiles.
10. On the Set Options page:
    1. Select Cluster or Instance for the system view.
       The system view determines whether the logical cluster users view the Cluster Edition as an entire cluster or as individual instances. This affects some queries and stored procedures.
    2. (Optional) Select Automatically start logical cluster to start the logical cluster when the shared cluster is started.
    3. Choose instance or group to specify whether the instances are brought online as a group or individually.
    4. (Optional) Select Fail to any to specify whether any instance, or a specific instance can be a failover resource.
    5. Choose the down-routing mode to specify how client connections are routed if the logical cluster designated by the routing rule is not available.
       • system – sends unroutable connections to the system logical cluster.
       • open – sends unroutable connections to the open logical cluster.
       • disconnect – disconnects unroutable connections.
    6. Choose a login distribution mode to specify how connections are distributed in logical clusters with multiple instances.
       Note: The login distribution mode does not affect single-instance logical clusters.

       • affinity – specifies that a connection accepted by an instance is retained as long as the target logical cluster is running on that instance. If the load profile specifies a load threshold, and the load on the instance is too high, the workload manager redirects the connection to the least loaded instance in a logical cluster. If the target logical cluster is not running on the instance, the workload manager redirects the connection to the least loaded instance in a logical cluster.
       • round-robin – specifies that incoming connections are distributed in a round-robin fashion among the instances hosting a logical cluster. For example, if “SalesLC” is running on “ase1” and “ase2”, the workload manager sends the first connection to “ase1,” the next to “ase2”, and so on. Load scores are not included in the algorithm.
    7. (Optional) Select Open role to indicate that all connections that are not routed to a logical cluster via an explicit routing rule are routed to the current open logical cluster. When you create a new cluster, the system logical cluster is automatically designated the open logical cluster. You can reassign the open role to another logical cluster. However, only one open logical cluster can exist per physical cluster.
11. (Optional) Click Summary to review your information.
12. Select Finish to build the logical cluster.