|
Oracle® Application Server Installation Guide
10g Release 2 (10.1.2) for Microsoft Windows Part No. B14094-02 |
|
 Previous |
 Next |
|
Oracle® Application Server Installation Guide
10g Release 2 (10.1.2) for Microsoft Windows Part No. B14094-02 |
|
|
Previous |
Next |
This chapter provides an overview of the high availability configurations supported by Oracle Application Server. Subsequent chapters provide the details.
Contents of this chapter:
Section 10.1, "Overview of High Availability Configurations"
Section 10.2, "Installation Order for High Availability Configurations"
This chapter provides only a brief overview of the high availability configurations in Oracle Application Server. For a complete description of the configurations, see the Oracle Application Server High Availability Guide.
Oracle Application Server supports the following types of high availability configurations:
For a quick summary of the high availability configurations, see Section 10.1.4, "Summary of Differences".
OracleAS Cold Failover Cluster configurations have the following characteristics:
Active and passive nodes. The active node handles all the requests. The passive node becomes the active node when the active node fails. A failover event occurs and the requests are routed to the passive node.
Shared disk. Typically, you install Oracle Application Server on the shared disk. The active and passive nodes have access to the shared disk, but only one node (the active node) mounts the shared disk at any given time.
Virtual IP and hostname. You need to set up a virtual IP and hostname for the active and passive nodes. During installation, you provide the virtual hostname. Clients use the virtual hostname to access the Oracle Application Server in an OracleAS Cold Failover Cluster configuration (for example, the virtual hostname is used in URLs). The virtual IP and hostname points to the active node. If the active node fails, the virtual IP and hostname switches to point to the new active node.
You can install OracleAS Infrastructure and the middle tier in OracleAS Cold Failover Cluster configurations. See Chapter 11, "Installing in High Availability Environments: OracleAS Cold Failover Cluster" for details.
OracleAS Cluster (Identity Management) configurations have the following characteristics:
Active nodes. All the nodes in an OracleAS Cluster (Identity Management) configuration are active. This means that all the nodes can handle requests. If a node fails, the remaining nodes handle all the requests.
Load balancer. You need a load balancer to load-balance the requests to all the active nodes. During installation, you enter the virtual server name configured on your load balancer. During runtime, clients use the virtual server name to access the OracleAS Cluster (Identity Management) configuration. The load balancer then directs the request to the appropriate node.
OracleAS Cluster (Identity Management) is used for installing Identity Management components in a high availability configuration. It is not used for middle tiers. For details on OracleAS Cluster (Identity Management), see Chapter 12, "Installing in High Availability Environments: OracleAS Cluster (Identity Management)".
OracleAS Disaster Recovery configurations have the following characteristics:
A production site and a standby site that mirrors the production site. Typically, these sites are located some distance from each other to guard against site failures such as floods, fires, or earthquakes. During normal operation, the production handles all the requests. If the production site goes down, the standby site takes over and handles all the requests.
Each site has all the hardware and software to run: it contains nodes for running OracleAS Infrastructure and the middle tiers; load balancers; and DNS servers.
OracleAS Disaster Recovery includes OracleAS Infrastructure and middle tiers. For details, see Chapter 13, "Installing in High Availability Environments: OracleAS Disaster Recovery".
Table 10-1 summarizes the differences among the high availability configurations:
Table 10-1 Differences Among the High Availability Configurations
|
|
OracleAS Cold Failover Cluster
|
OracleAS Cluster (Identity Management)
|
OracleAS Disaster Recovery
|
|---|---|---|---|
| Node configuration | Active-Passive | Active-Active | Active-Passive |
| Hardware cluster | Yes | No | Optional (hardware cluster required only if you installed the OracleAS Infrastructure in an OracleAS Cold Failover Cluster configuration) |
| Virtual hostname | Yes | No | Yes |
| Load balancer | No | Yes | No |
| Shared storage | Yes | No | No |
For all high availability configurations, you install the components in the following order:
OracleAS Metadata Repository
Identity Management components
If you are distributing the Identity Management components, you install them in the following order:
Oracle Internet Directory and Oracle Directory Integration and Provisioning
OracleAS Single Sign-On and Oracle Delegated Administration Services
Middle tiers
