Starting Stopping Names Servers

In the context of "Oracle Directory Naming", the "Oracle Names server" does not play a role. Oracle Names was deprecated starting in Oracle 9i and is no longer part of the Oracle networking architecture in more modern Oracle Database releases.
Instead, "Oracle Directory Naming" uses "LDAP-compliant directories" such as Oracle Internet Directory (OID) or other LDAP directories. These directories store 1) net service names and 2) database connect descriptors in a central location, making Oracle Names server obsolete.

• If referring to Oracle Names Server: Yes, in older versions where Oracle Names server was still in use, it needed to be started and stopped as part of its operations to provide name resolution services.
• If referring to Oracle Directory Naming (modern setups): There is no separate "Names" server to start or stop. Instead, the directory service itself (like OID or another LDAP directory) must be up and running for directory naming to function.

If you're managing a modern Oracle setup, you'll typically manage the directory service (OID or LDAP) rather than an Oracle Names server.

In Oracle Directory Naming within Oracle 19c, the **directory service** interacts with directory naming by serving as a centralized repository for net service names and database connect descriptors. This interaction can involve either **Oracle Internet Directory (OID)** or another **LDAP-compliant directory**. Here's how each operates:

1. Using Oracle Internet Directory (OID)

   OID is Oracle's implementation of an LDAP-compliant directory server. It integrates tightly with Oracle databases and the Oracle Net stack. Here's how it works:

   • Storing Net Service Names:
     • The Net Service Name and its associated Connect Descriptor are stored as entries in OID.
     • These entries conform to a predefined schema that Oracle provides within OID.
   • Interaction with Oracle Directory Naming:
     • Oracle Net clients and servers query OID to resolve a Net Service Name into its corresponding Connect Descriptor using LDAP queries.
     • For example, if a user attempts to connect to mydb.world, the client will issue an LDAP query to OID to retrieve the connect descriptor for mydb.world.
   • Advantages:
     • Centralized management of net service names.
     • Enhanced scalability for large environments.
     • Integration with other Oracle technologies (e.g., Enterprise User Security).
2. Using Another LDAP-Compliant Directory

   Oracle Directory Naming can also work with third-party LDAP-compliant directories, such as Microsoft Active Directory (AD) or OpenLDAP, as long as they conform to the LDAP protocol. Here’s how:

   • Schema Requirements:
     • The directory must support Oracle’s predefined LDAP schema for net service name resolution.
     • You may need to extend the third-party LDAP schema to include Oracle-specific object classes and attributes (e.g., orclNetService for net service names).
   • Configuration:
     • The ldap.ora file on Oracle clients and servers is configured to point to the third-party LDAP server.
     • This file specifies details such as the LDAP host, port, and base DN (Distinguished Name) where Oracle net service entries are stored.
   • Interaction Process:
     • Oracle Net clients issue LDAP queries to the third-party directory to look up net service names.
     • The directory responds with the associated connect descriptor.
   • Challenges:
     • Additional configuration may be required to extend schemas or set up integration.
     • Limited features compared to OID, especially in scenarios that involve deep Oracle-specific integration.

Summary of Directory Naming Workflow

1. Client Configuration:
   • Clients must have an ldap.ora file that points to the directory service (OID or other LDAP).
2. Name Resolution:
   • When a client initiates a connection using a net service name, Oracle Net issues an LDAP query to the directory service.
3. Response:
   • The directory service provides the connect descriptor for the requested service name.
4. Connection Establishment:
   • The client uses the connect descriptor to establish a session with the Oracle database.

Example: `ldap.ora` Configuration For both OID and other LDAP directories, you configure the `ldap.ora` file to specify the LDAP server details:

# ldap.ora configuration
DIRECTORY_SERVERS = (ldapserver.example.com:389)
DEFAULT_ADMIN_CONTEXT = "dc=example,dc=com"
DIRECTORY_SERVER_TYPE = OID   # For OID; use GENERIC for other LDAP servers

The startup command for the Names server is very similar to the start command for an Oracle listener. At startup time, Net Services displays all of the relevant parameter settings. From your server prompt, simply enter namesctl start. View the Code below to see the output of this command.

• namesctl start: The output from the namesctl start command is very similar to the namesctl stat command: both display all of the current configuration parameters.
• Stopping the Names Server: Stopping the Names server is also a simple command. Simply enter namesctl stop.
  

  Dilbert > namesctl Stop
  Confirm [yes or no]: yes
  Server shut down
  

The rules for starting and stopping the Names server are identical to the rules for starting and stopping the Oracle Listener. The Names server should be started after the Oracle databases are started. At shutdown time, the Names server should be stopped prior to stopping the Oracle databases. The next lesson concludes this module.