- Host Naming: Oracle resolves service names using their existing name resolution service, the name resolution service might be DNS,NIS, or simply a centrally-maintained set of /etc/hosts files. It allows users to connect to an Oracle server simply by using the server computers host name alias. No client configuration is required to take adavantage of this feature. The connection is established by using the default TCP/IP port for the listener (1521). Host naming can eliminate the need for a local naming configuration file (TNSNAMES.ORA) in environments where simple database connectivity is desired. However it is recommended for complex environments where features like connection pooling, heterogeneous services or application failover will be used.
Steps using Host Naming Option
- The client initiates a connect request providing a service name which is also a TCP/IP hostname or alias
- A host naming adapter resolves this service name by generating a network address using the service
name as both the TCP/IP hostname and the global database name. The port defaults to 1521.
- Net8 makes the connect request to the address created.
- A network listener, listening at registered TCP/IP port 1521, receives the request and establishes
a connection to the database with a matching global database name as specified in the listeners configuration
- The connection is accepted by the server
Host naming is used as a naming method by default, it will be used in the absence of a local naming configuration file and Names server.
- Local Naming : Is the method for resolving a service name to a network address by using information
configured on each individual client. Much like an address book, this information is entered in a local
naming configuration file called TNSNAMES.ORA . The process for establishing a connection is:
- The client initiates a connect request providing a service name
- The service name is resolved to a network address configured in a local naming file
- Net8 makes the connect request to the address provided
- A network listener receives the request and directs it to the database it is servicing
- The connection is accepted by the server.
To configure:
- Verify that "TNSNAMES" is listed in the field of selected naming methods in the client profile.If it is
not, use the Oracle Net8 Assistant to edit the profile.
- Verify that service names are correctly mapped to their appropriate network address in a local naming
configuration file (TNSNAMES.ORA).
- Centralized Naming using Oracle Names : Oracle names uses Name Servers to store the names and addresses
of all database services on the network.Name Servers resolve the service name to a network address and return
that information to the client. The process is as follows:
- The client initiates a connect request providing a service name
- The connect request is forwarded to a Names Server where the service name is resolved to a network
address. This address is returned to the client.
- Net8 makes the connect request to the address provided
- A network listener receives the request and redirects it to the database it is servicing
- The connection is accepted by the server
To configure :
- Verify that "ONAMES" is listed in the field of selected naming methods in your profile.
- Verify that a Names Server exists and is running on the network.
- External Naming.: This method refers to resolving a service name to a network address by using
supported non-Oracle naming service. Oracle Native Naming Adapters resolve service names stored in customers
native (non-Oracle) naming services. They include: Network Information Service (NIS) and Netware Directory Services (NDS). To establish a connection :
- The client initiates a connect request providing a service name.
- A native adapter forwards the request to a native naming system that resolves the service name
to a netowork address. The address is returned to the client.
- Net8 makes the connect request to the address provided.
- A network listener receives the request and redirects it to the database it is servicing.
- The connection is accepted by the server
To configure External Naming:
- Verify that the applicable Native Naming Adapter has been installed on the client node.
- Specify the use of an external naming adapter ( CDS, NDS,NIS) in your profile.
Oracle Names and Native Naming Adapters Oracle Names can be used in conjunction with other propietary
or open naming services to provide cross-environment name resolution. e.g. Oracle Native Naming Adapters
for CDS/DCE, NIS or NDS could be installed on all clients and servers in an enterprise network already
running Oracle to provide name resolution accross multiple name services. Since Oracle Names is a proprietary
name service storing and resolving names and addresses for Oracle database only, one names solution could
be to store all your Oracle services in Oracle Names, and use a directory service such as DNS or X.500 as your
global naming service.