Planning the HA for TimesTen Installation and Configuration

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This section contains the information you need to plan your HA for TimesTen installation and configuration.

Planning the Resource Group Topology for HA for TimesTen

TimesTen can be configured in the following ways, classified by the TimesTen replication configuration.

Table 2 TimesTen and Resource Group Topology

Replication Type	Resource group topology
No replication	Failover resource group
Master and one subscriber	Two failover resource groups
Master and multiple subscribers	One failover resource group plus one scalable or multiple-master resource group
Active-active	One multiple-master resource group for TimesTen plus one failover resource group for a logical host and potential applications.
Active-standby	One multiple-master resource group for the managing the server plus two failover resource groups for the active and the standby service

HA for TimesTen and Oracle Solaris Zones

HA for TimesTen is supported in Oracle Solaris Zones. Oracle Solaris Cluster offers the following concepts for Oracle Solaris Zones:

A zone cluster is an Oracle Solaris non-global zone of brand cluster that is created by using the clzonecluster command. A zone cluster forms a complete and separate cluster across the global-cluster nodes.
An HA zone is a non-global zone that is managed by the HA for Oracle Solaris Zones (HA for Solaris Zones) data service, and is represented by a resource of a resource group.

HA for TimesTen is configurable in a zone cluster but not in an HA zone.

HA for TimesTen and In-Memory Database Cache

TimesTen offers the option to configure data stores as in-memory database caches. This is a data store property and it is transparent to the HA for TimesTen agent. The underlying Oracle database can be made highly available in the same cluster as the in-memory database caches or in a different cluster.

Configuration Restrictions

The following configuration restrictions apply to HA for TimesTen.

Caution - Your data service configuration might not be supported if you do not observe these restrictions.

Combining data stores - The TimesTen database can manage multiple data stores with a single instance. However, you can only mix the data-store topology if the data stores match your resource-group topology. For example, if one data store requires a failover resource and the other requires a multiple-master resource, you cannot mix the data stores in one single TimesTen server resource.
Automatic startup - The TimesTen software installation provides an option to start the TimesTen server on system reboot. In an HA for TimesTen configuration, do not configure this option. HA for TimesTen controls the TimesTen server startup.
Recovery actions - The TimesTen server resource type does not perform TimesTen internal error recovery actions, such as the reduplication of data stores. Only an active-standby configuration uses this type of recovery. For all other configurations, these type of actions are manual procedures.
Node lists in an active-standby configuration - All resource groups that are part of an active-standby configuration must share the same node list.

Configuration Requirements

The following are configuration requirements for HA for TimesTen.

Caution - If your data service configuration does not conform to these requirements, the data service configuration might not be supported.

Dependencies between resource types – The dependencies between the HA for TimesTen resource types are described in the following table.

Resource Type	Dependency
`ORCL.TimesTen_server`	`SUNW.HAStoragePlus` is required if the configuration uses a highly available local file system. `SUNW.Logical_Hostname` is required for a failover resource. `SUNW.Shared_Address` is required for a scalable subscriber.
`ORCL.TimesTen_cldaemon`	An `ORCL.TimesTen_clag` resource is required in an active-standby configuration.
`ORCL.TimesTen_dbmon`	An `ORCL.TimesTen_cldaemon` resource is required in an active-standby configuration.
`ORCL.TimesTen_active`	An `ORCL.TimesTen_dbmon` resource is required in an active-standby configuration.
`ORCL.TimesTen_standby`	An `ORCL.TimesTen_dbmon` resource is required in an active-standby configuration.

You set these dependencies when you register and configure HA for TimesTen. For more information, see Registering and Configuring HA for TimesTen.

If more elaborate dependencies are required, see the r_properties(5) and rg_properties(5) man pages for further dependencies and affinities settings.

Replication policies and cache policies – Except for active-standby configurations, in all configurations that use replication and in-memory database cache, the startup policy for the replication and the cache must be set to always.