Skip Headers
Oracle® Application Server High Availability Guide
10g Release 2 (10.1.2)
B14003-03
  Go To Documentation Library
Home
Go To Product List
Solution Area
Go To Table Of Contents
Contents
Go To Index
Index

Previous
Previous
Next
Next
 

11 Oracle Internet Directory in Oracle Real Application Clusters Environment

Oracle Real Application Clusters is a computing environment that harnesses the processing power of multiple, interconnected computers. Along with a collection of hardware, called a cluster, it unites the processing power of each component to become a single, robust computing environment. A cluster comprises two or more computers, also called nodes.

This chapter discusses the ways you can run Oracle Internet Directory in an Oracle Real Application Clusters system. It contains these topics:

11.1 Terminology

11.2 Installing Oracle Internet Directory against a Real Application Clusters Database

For information on installing Oracle Internet Directory against a Real Application Clusters database, see the chapter entitled "Installing in High Availability Environments: OracleAS Cluster (Identity Management)" in the Oracle Application Server Installation Guide.

11.3 Oracle Internet Directory in an Oracle Real Application Clusters Environment

To achieve a very comprehensive high availability configuration, you can configure Oracle Internet Directory to run in the Real Application Clusters active-active mode. This involves running Oracle Internet Directory processes and the Oracle Internet Directory-designated database on all the Real Application Clusters nodes.

Figure 11-1 shows a two-node cluster on which an Oracle Real Application Clusters database is configured.

Figure 11-1 Oracle Internet Directory with Basic High Availability Configuration

This illustration is described in the text.

As Figure 11-1 shows:

11.4 Oracle Directory Server Connection Modes to Real Application Clusters Database Instances

This section discusses the various connection modes possible for Oracle directory server instances communicating with Oracle Real Application Clusters database instances. These connection modes are transparent to the Oracle Internet Directory clients, and do not affect the way in which Oracle Internet Directory communicates with its clients.

This section contains these topics:

11.4.1 Load_balance Parameter

If the load_balance parameter in the tnsnames.ora file is set to ON, then Oracle Internet Directory connections to the Oracle Database are distributed to each Oracle Database node. During failover of any node, only connections to the failed node are redirected to the available Oracle Database nodes.

If the load_balance parameter is set to off, then all the Oracle Internet Directory connections to the Oracle Database are to one Oracle Database node only.

During failover, all the connections are redirected to the available Oracle Database nodes.

11.4.2 Connect-Time Failover (CTF)

At the time of connection to the Oracle Database by the Oracle directory servers, if the primary Oracle Database node is not available, then Oracle Internet Directory servers connect to the backup—that is, secondary—database.

11.4.3 Transparent Application Failover (TAF)

To configure TAF, in the tnsnames.ora file, add type=select and method=preconnect.

During any LDAP search operation, if the primary Oracle Database node fails, then the Oracle directory server transparently connects to the backup—that is, the secondary—Oracle Databasee node, and the current LDAP search operation continues.

11.4.4 Configuring the tnsnames.ora File for the Failover

This section shows configurations of the tnsnames.ora files on two nodes.

Node 1

db.us.acme.com= 
 (description=  
  (load_balance=off/on)  /* only connect time load balancing & connection load balancing */
  (failover=on)          /* only connect time failover */
  (address=  
       (protocol=tcp)  
       (host=db1)  
       (port=1521)) 
 (address=  
       (protocol=tcp)  
       (host=db2)  
       (port=1521)) 
  (connect_data= 
     (service_name=db.us.acme.com) 
     (failover_mode=
       (backup=db2.acme.com)
       (type=select) 
       (method=preconnect))))

db2.acme.com= 
 (description=  
  (address=  
       (protocol=tcp)  
       (host=db2)  
       (port=1521)) 
  (connect_data= 
     (service_name=db.us.acme.com) 
     (instance_name=db2)
     (failover_mode=
     (backup=db2.acme.com)
     (type=select)
     (method=preconnect))
     ))

Node 2

db.us.acme.com= 
 (description=  
  (load_balance=off/on)  /* only connect time load balancing & connection load balancing */
  (failover=on)          /* only connect time failover */
  (address=  
       (protocol=tcp)  
       (host=db2)  
       (port=1521)) 
 (address=  
       (protocol=tcp)  
       (host=db1)  
       (port=1521)) 
  (connect_data= 
     (service_name=db.us.acme.com) 
     (failover_mode=
       (backup=db1.acme.com)
       (type=select) 
       (method=preconnect))))

db1.acme.com= 
 (description=  
  (address=  
       (protocol=tcp)  
       (host=db1)  
       (port=1521)) 
  (connect_data= 
     (service_name=db.us.acme.com) 
     (instance_name=db2)
     (failover_mode=
     (backup=db2.acme.com)
     (type=select)
     (method=preconnect))))

11.5 Oracle Directory Replication Between Oracle Internet Directory Real Application Clusters Nodes

Directory replication can be configured between two or more Oracle Internet Directory Real Application Clusters nodes.


Note:

If the primary node running either the directory replication server (oidrepld), or the Oracle directory integration and provisioning server (odisrv), or both fails, then the OID Monitor on the secondary node starts these processes on the secondary node after five minutes. However, when the primary node is restarted, these servers are not automatically restarted on the primary node.

Normal shutdown is not treated as a failover—that is, after a normal shutdown, the OID Monitor on the secondary node does not start these processes on the secondary node after five minutes. However, as in the case of a failure, when the primary node is restarted, these servers are not automatically restarted on the primary node.


11.6 About Changing the ODS Password on a Real Application Clusters Node

If you change the ODS password on one Real Application Clusters node by using the OID Database Password Utility, then you must update the wallet $ORACLE_HOME/ldap/admin/oidpwdlldap1 on the other Real Application Clusters nodes. Do this either by copying the changed wallet to all the nodes, or by invoking the OID Database Password Utility on all other nodes to update the wallet file only. This applies to the replication password changes also. Here the Replication Environment Management Tool is used instead of the OID Database Password Utility.