6 Local Naming Parameters in the tnsnames.ora File

This chapter provides a complete listing of the tnsnames.ora file configuration parameters.

6.1 Overview of Local Naming Parameters

The tnsnames.ora file is a configuration file that contains network service names mapped to connect descriptors for the local naming method, or net service names mapped to listener protocol addresses.

A net service name is an alias mapped to a database network address contained in a connect descriptor. A connect descriptor contains the location of the listener through a protocol address and the service name of the database to which to connect. Clients and database servers (that are clients of other database servers) use the net service name when making a connection with an application.

By default, the tnsnames.ora file is located in the ORACLE_HOME/network/admin directory. Oracle Net will check the other directories for the configuration file. For example, the order checking the tnsnames.ora file is as follows:

  1. The directory specified by the TNS_ADMIN environment variable. If the file is not found in the directory specified, then it is assumed that the file does not exist.

  2. If the TNS_ADMIN environment variable is not set, then Oracle Net checks the ORACLE_HOME/network/admin directory.

Note:

On Microsoft Windows, the TNS_ADMIN environment variable is used if it is set in the environment of the process. If the TNS_ADMIN environment variable is not defined in the environment, or the process is a service which does not have an environment, then Microsoft Windows scans the registry for a TNS_ADMIN parameter.

See Also:

6.2 General Syntax of tnsnames.ora

The basic syntax for a tnsnames.ora file is shown in Example 6-1.

Example 6-1 Basic Format of tnsnames.ora File

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS=(protocol_address_information))
   (CONNECT_DATA= 
     (SERVICE_NAME=service_name))) 

In the preceding example, DESCRIPTION contains the connect descriptor, ADDRESS contains the protocol address, and CONNECT_DATA contains the database service identification information.

6.3 Multiple Descriptions in tnsnames.ora

A tnsnames.ora file can contain net service names with one or more connect descriptors. Each connect descriptor can contain one or more protocol addresses. Example 6-2 shows two connect descriptors with multiple addresses. DESCRIPTION_LIST defines a list of connect descriptors.

Example 6-2 Net Service Name with Multiple Connect Descriptors in tnsnames.ora

net_service_name= 
 (DESCRIPTION_LIST=
  (DESCRIPTION= 
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
  (DESCRIPTION= 
   (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-svr)(PORT=1521))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com))))

Note:

Oracle Net Manager does not support the creation of multiple connect descriptors for a net service name when using Oracle Connection Manager.

6.4 Multiple Address Lists in tnsnames.ora

The tnsnames.ora file also supports connect descriptors with multiple lists of addresses, each with its own characteristics. In Example 6-3, two address lists are presented. The first address list features client load balancing and no connect-time failover, affecting only those protocol addresses within its ADDRESS_LIST. The second protocol address list features no client load loading balancing, but does have connect-time failover, affecting only those protocol addresses within its ADDRESS_LIST. The client first tries the first or second protocol address at random, then tries protocol addresses three and four sequentially.

Example 6-3 Multiple Address Lists in tnsnames.ora

net_service_name= 
 (DESCRIPTION= 
  (ADDRESS_LIST= 
   (LOAD_BALANCE=on)
   (FAILOVER=off)
   (ADDRESS=(protocol_address_information))
   (ADDRESS=(protocol_address_information)))
  (ADDRESS_LIST= 
   (LOAD_BALANCE=off)
   (FAILOVER=on)
   (ADDRESS=(protocol_address_information))
   (ADDRESS=(protocol_address_information)))
  (CONNECT_DATA=
   (SERVICE_NAME=service_name)))

Note:

  • Oracle Net Manager supports only the creation of one protocol address list for a connect descriptor.

  • Oracle Net Services supports the IFILE parameter in the tnsnames.ora file, with up to three levels of nesting. The parameter is added manually to the file. The following is an example of the syntax:

    IFILE=/tmp/listener_em.ora
    IFILE=/tmp/listener_cust1.ora
    IFILE=/tmp/listener_cust2.ora 
    

    Refer to Oracle Database Reference for additional information.

6.5 Connect-Time Failover and Client Load Balancing with Oracle Connection Managers

When a connect descriptor in a tnsnames.ora file contains at least two protocol addresses for Oracle Connection Manager, parameters for connect-time failover and load balancing can be included in the file.

Example 6-4 Multiple Oracle Connection Manager Addresses in tnsnames.ora

This example illustrates failover of multiple Oracle Connection Manager protocol addresses.

sample1=
 (DESCRIPTION= 
   (SOURCE_ROUTE=yes) 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))    # 1 
     (ADDRESS_LIST=  
       (FAILOVER=on) 
       (LOAD_BALANCE=off)                               #  2 
       (ADDRESS=(PROTOCOL=tcp)(HOST=host2a)(PORT=1630)) 
       (ADDRESS=(PROTOCOL=tcp)(HOST=host2b)(PORT=1630)))
     (ADDRESS=(PROTOCOL=tcp)(HOST=host3)(PORT=1521)))    #  3
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

Here, the syntax does the following:

  1. The client is instructed to connect to the protocol address of the first Oracle Connection Manager, as indicated by:

    (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))
  2. The first Oracle Connection Manager is instructed to connect to the first protocol address of another Oracle Connection Manager. If the first protocol address fails, then it tries the second protocol address. This sequence is specified with the following configuration:

    (ADDRESS_LIST=  
      (FAILOVER=on) 
      (LOAD_BALANCE=off)
      (ADDRESS=(PROTOCOL=tcp)(HOST=host2a)(PORT=1630)) 
      (ADDRESS=(PROTOCOL=tcp)(HOST=host2b)(PORT=1630))) 
    
  3. Oracle Connection Manager connects to the database service using the following protocol address:

    (ADDRESS=(PROTOCOL=tcp)(HOST=host3)(PORT=1521))

Example 6-5 Client Load Balancing in tnsnames.ora

This example illustrates client load balancing among two Oracle Connection Managers and two protocol addresses:

sample2=
 (DESCRIPTION= 
   (LOAD_BALANCE=on)                                    # 1
   (FAILOVER=on)
   (ADDRESS_LIST= 
     (SOURCE_ROUTE=yes) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))    # 2
     (ADDRESS=(PROTOCOL=tcp)(HOST=host2)(PORT=1521)))
  (ADDRESS_LIST= 
     (SOURCE_ROUTE=yes) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host3)(port=1630)) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host4)(port=1521)))
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))  # 3

Here, the syntax does the following:

  1. The client is instructed to pick an ADDRESS_LIST at random and to fail over to the other if the chosen ADDRESS_LIST fails. This is indicated by the LOAD_BALANCE and FAILOVER parameters being set to on.

  2. When an ADDRESS_LIST is chosen, the client first connects to Oracle Connection Manager, using the Oracle Connection Manager protocol address that uses port 1630 indicated for the ADDRESS_LIST.

  3. Oracle Connection Manager then connects to the database service, using the protocol address indicated for the ADDRESS_LIST.

6.6 Connect Descriptor Descriptions

Each connect descriptor is contained within the DESCRIPTION parameter. Multiple connect descriptors are characterized by the DESCRIPTION_LIST parameter.

6.6.1 DESCRIPTION_LIST

DESCRIPTION_LIST networking parameter of the tnsnames.ora file defines a list of connect descriptors for a particular net service name.

Purpose

To define a list of connect descriptors for a particular net service name.

Example 6-6 Example

net_service_name= 
(DESCRIPTION_LIST=
 (DESCRIPTION=
  (ADDRESS=...)
  (CONNECT_DATA=(SERVICE_NAME=sales.example.com)))
 (DESCRIPTION=

6.6.2 DESCRIPTION

DESCRIPTION networking parameter of the tnsnames.ora file specifies a container for a connect descriptor.

Purpose

To specify a container for a connect descriptor.

Usage Notes

When using more than one DESCRIPTION parameter, put the parameters under the DESCRIPTION_LIST parameter.

Example 6-7 Example

net_service_name=
(DESCRIPTION=
  (ADDRESS=...)
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

6.7 Protocol Address Section

The protocol address section of the tnsnames.ora file specifies the protocol addresses of the listener. If there is only one listener protocol address, then use the ADDRESS parameter. If there is more than one address, then use the ADDRESS_LIST parameter.

6.7.1 ADDRESS

The ADDRESS networking parameter is in the tnsnames.ora file and it specifies the protocol address under the ADDRESS_LIST or the DESCRIPTION parameter for one listener.

Purpose

To specify a single listener protocol address.

Usage Notes

Put this parameter under either the ADDRESS_LIST parameter or the DESCRIPTION parameter.

Example

net_service_name=
(DESCRIPTION= 
 (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
 (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

6.7.2 HTTPS_PROXY

Learn to use the tnsnames.ora parameter HTTPS_PROXY to specify HTTP proxy host names to tunnel Transport Layer Security (TLS) client connections.

Purpose

To specify HTTP proxy host name for tunneling TLS client connections.

Usage Notes

The clients can tunnel secure connections over forward HTTP proxy using HTTP CONNECT method. This helps in accessing the public cloud database service as it eliminates the requirement to open an outbound port on a client side firewall. This parameter is applicable only to the connect descriptors where PROTOCOL=TCPS. This is similar to the web browser setting for intranet users who want to connect to internet hosts. Increase the forward web proxy read timeout for requests to a higher value depending on client queries. Otherwise, the forward web proxy closes the connection assuming that no requests are made from the client.

Successful connection depends on specific proxy configurations. The performance of data transfers depends on proxy capacity. Oracle recommends not to use this feature in production environments where performance is critical.

Configuring tnsnames.ora for the HTTP proxy may not be enough depending your organization’s network configuration and security policies. For example, some networks require a username and password for the HTTP proxy.

Oracle Client versions earlier than 18c does not support connections through HTTP proxy.

Contact your network administrator to open outbound connections to hosts in the oraclecloud.com domain using the relevant port, without going through an HTTP proxy. For example, port 1522.

Default

None

Values

HTTP proxy host name that can make an outbound connection to the internet hosts.

Example

HTTPS_PROXY=www-proxy.mycompany.com

6.7.3 HTTPS_PROXY_PORT

Learn how to use the tnsnames.ora parameter HTTPS_PROXY_PORT to specify forward HTTP proxy host ports for tunneling Transport Layer Security (TLS) client connections.

Purpose

To specify forward HTTP proxy host port for tunneling TLS client connections.

Usage Notes

It forwards the HTTP proxy host port that receives HTTP CONNECT method. This parameter should be used along with HTTPS_PROXY_PORT. This value takes effect only when SQLNET.USE_HTTPS_PROXY=1 is set in sqlnet.ora.

Default

none

Values

port number

Example

HTTPS_PROXY_PORT=80

6.7.4 ADDRESS_LIST

The ADDRESS_LIST networking parameter specifies the number of protocol addresses.

Purpose

To define a list of protocol addresses.

Usage Notes

If there is only one listener protocol address, then ADDRESS_LIST is not necessary.

Put this parameter either under the DESCRIPTION parameter or the DESCRIPTION_LIST parameter.

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

6.8 Optional Parameters for Address Lists

For multiple addresses, you can use the optional parameters to configure address lists.

6.8.1 ENABLE

Purpose

To allow the caller to detect a terminated remote server, typically it takes 2 hours or more to notice.

Usage Notes

The keepalive feature on the supported TCP transports can be enabled for a net service client by putting (ENABLE=broken) under the DESCRIPTION parameter in the connect string. On the client side, the default for tcp_keepalive is off. Operating system TCP configurables, which vary by platform, define the actual keepalive timing details.

Values

broken

Example

net_service_name=
 (DESCRIPTION= 
  (ENABLE=broken)
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Although the preceding example has multiple addresses, the ADDRESS_LIST parameter was not used. This is because the ADDRESS_LIST parameter is not mandatory.

6.8.2 FAILOVER

Purpose

To enable or disable connect-time failover for multiple protocol addresses.

Usage Notes

When you set the parameter to on, yes, or true, Oracle Net fails over at connect time to a different address if the first protocol address fails. When you set the parameter to off, no, or false, Oracle Net tries one protocol address.

Put this parameter under the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Note:

Do not set the GLOBAL_DBNAME parameter in the SID_LIST_listener_name section of the listener.ora. A statically configured global database name disables connect-time failover.

Default

on for the DESCRIPTION_LIST, DESCRIPTION, and ADDRESS_LIST parameters

Values

  • yes | on | true

  • no | off | false

Example

net_service_name=
 (DESCRIPTION= 
  (FAILOVER=on)
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

6.8.3 LOAD_BALANCE

Purpose

To enable or disable client load balancing for multiple protocol addresses.

Usage Notes

When you set the parameter to on, yes, or true, Oracle Net goes through the list of addresses in a random sequence, balancing the load on the various listener or Oracle Connection Manager protocol addresses. When you set the parameter to off, no, or false, Oracle Net tries the protocol addresses sequentially until one succeeds.

Put this parameter under the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Default

on for DESCRIPTION_LIST

Values

  • yes | on | true

  • no | off | false

Example

net_service_name=
 (DESCRIPTION= 
  (LOAD_BALANCE=on)
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

6.8.4 RECV_BUF_SIZE

Use the RECV_BUF_SIZE parameter to specify buffer space for session receive operations.

Purpose

To specify, in bytes, the buffer space for receive operations of sessions.

Usage Notes

This parameter is supported by the TCP/IP, TCP/IP with TLS, and SDP protocols.

Put this parameter under the DESCRIPTION parameter or at the end of the protocol address.

Setting this parameter in the connect descriptor for a client overrides the RECV_BUF_SIZE parameter at the client-side sqlnet.ora file.

Note:

Additional protocols might support this parameter on certain operating systems. Refer to the operating system-specific documentation for additional information about additional protocols.

Default

The default value for this parameter is specific to the operating system. The default for the Linux 2.6 operating system is 87380 bytes.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)
        (RECV_BUF_SIZE=11784))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)
        (RECV_BUF_SIZE=11784))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
net_service_name= 
 (DESCRIPTION= 
   (RECV_BUF_SIZE=11784)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-server)(PORT=1521)))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com)))

6.8.5 SDU

Purpose

To instruct Oracle Net to optimize the transfer rate of data packets being sent across the network with a specified session data unit (SDU) size.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

Setting this parameter in the connect descriptor for a client overrides the DEFAULT_SDU_SIZE parameter at client-side sqlnet.ora file.

Default

8192 bytes (8 KB)

Values

512 to 2097152 bytes.

Example

net_service_name= 
 (DESCRIPTION=
  (SDU=8192)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))

6.8.6 SEND_BUF_SIZE

Use the SEND_BUF_SIZE parameter to specify buffer space for session send operations.

Purpose

To specify, in bytes, the buffer space for send operations of sessions.

Usage Notes

This parameter is supported by the TCP/IP, TCP/IP with TLS, and SDP protocols.

Put this parameter under the DESCRIPTION parameter or at the end of the protocol address.

Setting this parameter in the connect descriptor for a client overrides the SEND_BUF_SIZE parameter at the client-side sqlnet.ora file.

Note:

Additional protocols might support this parameter on certain operating systems. Refer to the operating system-specific documentation for information about additional protocols.

Default

The default value for this parameter is operating system specific. The default for the Linux 2.6 operating system is 16 KB.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)
        (SEND_BUF_SIZE=11784))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)
        (SEND_BUF_SIZE=11784)))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
net_service_name= 
 (DESCRIPTION= 
   (SEND_BUF_SIZE=11784)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-server)(PORT=1521)
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-server)(PORT=1521)))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com)))

6.8.7 SOURCE_ROUTE

Purpose

To enable routing through multiple protocol addresses.

Usage Notes

When you set this parameter to on or yes, Oracle Net uses each address in order until the destination is reached.

To use Oracle Connection Manager, an initial connection from the client to Oracle Connection Manager is required, and a second connection from Oracle Connection Manager to the listener is required.

Put this parameter under either the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Default

off

Values

  • yes | on

  • no | off

Example

net_service_name=
 (DESCRIPTION= 
  (SOURCE_ROUTE=on)
  (ADDRESS=(PROTOCOL=tcp)(HOST=cman-pc)(PORT=1630))
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

See Also:

Oracle Database Net Services Administrator's Guide for complete configuration information

6.8.8 TYPE_OF_SERVICE

Purpose

To specify the type of service to use for an Oracle Rdb database.

Usage Notes

This parameter should only be used if the application supports both an Oracle Rdb and Oracle database service, and you want the application to load balance between the two.

Put this parameter under the DESCRIPTION parameter.

Example

net_service_name=
 (DESCRIPTION_LIST=
  (DESCRIPTION=
   (ADDRESS=...)
   (CONNECT_DATA= 
    (SERVICE_NAME=generic)
    (RDB_DATABASE=[.mf]mf_personal.rdb)
    (GLOBAL_NAME=alpha5))
   (TYPE_OF_SERVICE=rdb_database))
  (DESCRIPTION=
   (ADDRESS=...)
   (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))
   (TYPE_OF_SERVICE=oracle11_database)))

6.9 Connection Data Section

Learn how to configure network connections with protocol addresses.

A network object is identified by a protocol address. When a connection is made, the client and the receiver of the request (listener or Oracle Connection Manager) are configured with identical protocol addresses. The client uses this address to send the connection request to a particular network object location, and the recipient "listens" for requests on this address, and grants a connection based on its address information matching the client information.

6.9.1 COLOCATION_TAG

Purpose

To direct the listener to route all connections with the same colocation_tag to the same database instance.

Usage Notes

Use this parameter with the CONNECT_DATA parameter.

The parameter value must be an alphanumeric string.

Example


net_service_name=
 (DESCRIPTION=
   (ADDRESS_LIST=
    (ADDRESS=...)
    (ADDRESS=...))
 (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (COLOCATION_TAG=abc)))

Note:

Under certain conditions, such as, when maximum load of an instance is reached or when new instances are added or deleted for a service, the colocation of client connections that have the same colocation_tag to the same database instance may not be consistent.

6.9.2 CONNECT_DATA

Purpose

To define the service to which to connect, such as SERVICE_NAME.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

CONNECT_DATA permits the following additional parameters:

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)))

6.9.3 FAILOVER_MODE

Purpose

To instruct Oracle Net to fail over to a different listener if the first listener fails during run time.

Usage Notes

Depending upon the configuration, the session or any SELECT statements which were in progress are automatically failed over.

This type of failover is called Transparent Application Failover (TAF) and should not be confused with the connect-time failover FAILOVER parameter.

Put this parameter under the CONNECT_DATA parameter.

Additional Parameters

FAILOVER_MODE supports the following parameters:

  • BACKUP: Specifies the failover node by its net service name. A separate net service name must be created for the failover node.

  • TYPE: Specifies the type of failover. Three types of Oracle Net failover functionality are available by default to Oracle Call Interface (OCI) applications:

    • SESSION: Fails over the session. For example, if a user's connection is lost, then a new session is automatically created for the user on the backup. This type of failover does not attempt to recover selects.

    • SELECT: Allows users with open cursors to continue fetching them after failure. However, this mode involves overhead on the client side in normal select operations.

    • NONE: This is the default, in which no failover functionality is used. This can also be explicitly specified to prevent failover from happening.

  • METHOD: Specifies how fast failover is to occur from the primary node to the backup node:

    • BASIC: Establishes connections at failover time. This option requires almost no work on the backup database server until failover time.

    • PRECONNECT: Pre-establishes connections. This provides faster failover but requires that the backup instance be able to support all connections from every supported instance.

  • TRANSACTION: Allows the database to complete the current database transaction following a recoverable error. This parameter is used with the COMMIT_OUTCOME=TRUE parameter.

  • RETRIES: Specifies the number of times to attempt to connect after a failover. If DELAY is specified, then RETRIES defaults to five retry attempts.

  • DELAY: Specifies the amount of time in seconds to wait between connect attempts. If RETRIES is specified, then DELAY defaults to one second.

Note:

If a callback function is registered, then RETRIES and DELAY parameters are ignored.

See Also:

Oracle Database Net Services Administrator's Guide for additional configuration information

6.9.4 GLOBAL_NAME

Purpose

To identify the Oracle Rdb database.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
    (ADDRESS=...)
    (ADDRESS=...))
   (CONNECT_DATA=
    (SERVICE_NAME=generic)
    (RDB_DATABASE=[.mf]mf_personal.rdb)
    (GLOBAL_NAME=alpha5)))

6.9.5 HS

Purpose

To direct Oracle Net to connect to a non-Oracle system through Heterogeneous Services.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Default

None

Values

ok

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
    (SID=sales6)
    )
(HS=ok))

See Also:

Oracle Database Net Services Administrator's Guide for complete configuration information

6.9.6 INSTANCE_NAME

Purpose

To identify the database instance to access.

Usage Notes

Set the value to the value specified by the INSTANCE_NAME parameter in the initialization parameter file.

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     (INSTANCE_NAME=sales1)))

See Also:

Oracle Database Net Services Administrator's Guide for additional information about the use of INSTANCE_NAME

6.9.7 KERBEROS5_PRINCIPAL

Use this parameter to specify Kerberos principals.

Purpose

When you configure Kerberos authentication for an Oracle Database client, you can specify multiple Kerberos principals with a single Oracle Database client.

This is an optional parameter. When specified, it is used to verify if the principal name in the credential cache matches the parameter value.

Usage Notes

Use this parameter with the CONNECT_DATA parameter. Alternatively, you can specify KERBEROS5_CC_NAME in the connect string along with the optional KERBEROS5_PRINCIPAL parameter to connect as a different Kerberos principal. Each Kerberos principal must have a valid credential cache.

Example

For a user krbuser1, who is externally authenticated using the Kerberos principal krbprinc1.example.com and the credential cache for this principal is located at /tmp/krbuser1/krb.cc, the connect string is:

net_service_name=
(DESCRIPTION=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
      (CONNECT_DATA=(SERVICE_NAME=sales.example.com)) 
      (SECURITY=
          (KERBEROS5_CC_NAME=/tmp/krbuser1/krb.cc)
          (KERBEROS5_PRINCIPAL=krbprinc1@example.com)))

Note:

The connection fails if the principal in the /tmp/krbuser1/krb.cc file does not contain the krbprinc1@example.com value.
Similarly, for a user krbuser2, who is externally authenticated using the Kerberos principal krbprinc2.example.com and the credential cache for this principal is located at /tmp/krbuser2/krb.cc, the connect string is:

net_service_name=
(DESCRIPTION=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
      (CONNECT_DATA=(SERVICE_NAME=sales.example.com)) 
      (SECURITY=
          (KERBEROS5_CC_NAME=/tmp/krbuser2/krb.cc)
          (KERBEROS5_PRINCIPAL=krbprinc2@example.com)))

6.9.8 RDB_DATABASE

Purpose

To specify the file name of an Oracle Rdb database.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     (RDB_DATABASE= [.mf]mf_personal.rdb)))

6.9.9 SHARDING_KEY

Use this parameter to route the database connection request to an appropriate shard. Put this parameter under the CONNECT_DATA section of a connect string.

Purpose

To specify the value of sharding key. Based on the value specified during a database connection request, the request is directly routed to an appropriate shard.

Usage Notes

Use the SHARDING_KEY parameter to specify sharding key in simplified text format. This parameter supports only ASCII character set and not special characters. The following data types are supported for sharding key:

  • NUMBER

  • INTEGER

  • SMALLINT

  • RAW

  • NVARCHAR

  • NVARCHAR2

  • NCHAR

  • DATE

  • TIMESTAMP

Use the SHARDING_KEY_B64 parameter to specify the base64-encoded binary representation of sharding key. This parameter supports special characters (such as " quotation mark , comma ( ) close parenthesis + plus sign).

Values

The fields for base64-encoded values (*_B64) start with a header, which is a sequence of space-separated integer values:

(CONNECT_DATA=(SHARDING_KEY_B64=[version] [type] [key column 1 type identifier] [key column 2 type identifier] ... ,[base64 string],[base64 string],[base64 string],...))... 
In the above syntax:
  • Parts of the compound key are separated with comma.

  • version specifies the version number of base64 representation. Currently, only version 1 is supported and thus the supported version value is 1.

  • type specifies the character set string and its encoding information. The supported type values are:

    Value Character Set String Encoding Scheme

    0

    String contains hash value.

    Character values are encoded in AL32UTF8 (for VARCHAR) and AL16UTF16 (for NVARCHAR).

    1

    String does not contain hash value.

    2

    String does not contain hash value.

    Character values are encoded in database encoding, which may be specific for each column.

    3

    String contains hash value.

    4

    String contains only hash value.

  • key column type identifier specifies the data types. The supported key column type identifier values are:

    Value Data Type

    1

    VARCHAR, NVARCHAR, CHAR, NCHAR

    2

    NUMBER

    6

    NUMBER with length in first byte

    12

    DATE

    23

    RAW

    180

    TIMESTAMP

  • The header is terminated by comma and is followed by base64 string. base64 string is a comma-separated list of the base64-encoded value string. The hash value, if available, is the last value in the list.

Example 6-8

In the following sample connect string, the SHARDING_KEY parameter value is specified in simplified text format:
net_service_name
(DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     ((SHARDING_KEY=40598230))))

Example 6-9

In the following sample connect string, the SHARDING_KEY_B64 parameter value is encoded to base64 binary representation:
net_service_name
(DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     ((SHARDING_KEY_B64=1 1 2,VVM=,OTQwMDI=))))

6.9.10 SUPER_SHARDING_KEY

Use this parameter in the case of composite sharding to route the database request to a collection of shards (shardspace). Put this parameter under the CONNECT_DATA section of a connect string.

Purpose

To specify shardspace key for a collection of shards. A shardspace is set of shards that store data that corresponds to a range or list of key values. Based on the value specified during a database connection request, the request is directly routed to an appropriate shardspace.

Usage Notes

Use the SUPER_SHARDING_KEY parameter to specify shardspace key for a collection of shards in simplified text format. This parameter supports only ASCII character set and not special characters. The supported data types for super sharding key are the same as those for sharding key.

Use the SUPER_SHARDING_KEY_B64 parameter to specify the base64-encoded binary representation of shardspace key. This parameter supports special characters (such as " quotation mark , comma ( ) close parenthesis + plus sign).

Values

The fields for base64-encoded values (*_B64) start with a header, which is a sequence of space-separated integer values:
(CONNECT_DATA=(SUPER_SHARDING_KEY_B64=[version] [type] [integer literal] [integer literal] ... ,[base64 binary],[base64 binary],[base64 binary],...))... 
For details on each of the base64-encoded header fields, see SHARDING_KEY.

Example 6-10

In the following sample connect string, the SHARDING_KEY and SUPER_SHARDING_KEY parameter values are specified in simplified text format:
net_service_name=
(DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     ((SHARDING_KEY=40598230)(SUPER_SHARDING_KEY=gold)))

Example 6-11

In the following sample connect string, the SHARDING_KEY_B64 and SUPER_SHARDING_KEY_B64 parameter values are encoded to base64 binary representation:
net_service_name
(DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     ((SHARDING_KEY_B64=1 1 2,VVM=,OTQwMDI=)(SUPER_SHARDING_KEY_B64=1 1,BBWEPGRBBDOEMGQW)))

6.9.11 SERVER

Purpose

To direct the listener to connect the client to a specific type of service handler.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Values

  • dedicated to specify whether client requests be served by dedicated server.

  • shared to specify whether client requests be served by a dispatcher or shared server.

  • pooled to get a connection from the connection pool if database resident connection pooling is enabled on the server.

Note:

  • Shared server must be configured in the database initialization file in order for the client to connect to the database with a shared server process.

  • The USE_DEDICATED_SERVER parameter in the sqlnet.ora file overrides this parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (SERVER=dedicated)))

6.9.12 SERVICE_NAME

Purpose

To identify the Oracle Database database service to access.

Usage Notes

Set the value to a value specified by the SERVICE_NAMES parameter in the initialization parameter file.

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))

6.10 Security Section

The security section of the tnsnames.ora file specifies these security-related parameters for use with Oracle security features.

6.10.1 IGNORE_ANO_ENCRYPTION_FOR_TCPS

The IGNORE_ANO_ENCRYPTION_FOR_TCPS parameter specifies if the SQLNET.ENCRYPTION_CLIENT parameter should be ignored for this specific TNS alias.

Purpose

To specify if the SQLNET.ENCRYPTION_CLIENT parameter should be ignored for this specific TNS alias.

Usage Notes

If your requirements are that SQLNET.ENCRYPTION_SERVER be set to required, then you can set the IGNORE_ANO_ENCRYPTION_FOR_TCPS parameter in both SQLNET.ENCRYPTION_CLIENT and SQLNET.ENCRYPTION_SERVER to TRUE. This forces the client to ignore the value that is set for the SQLNET.ENCRYPTION_CLIENT parameter for all outgoing TCPS connections.

Default

FALSE

Example 6-12 Example

test_ssl=
    (DESCRIPTION =
       (ADDRESS=(PROTOCOL=tcps)(HOST=)(PORT=1750))
       (CONNECT_DATA=(SID=^ORACLE_SID^))
       (SECURITY=(IGNORE_ANO_ENCRYPTION_FOR_TCPS=TRUE))
     ) 

6.10.2 SECURITY

Use the SECURITY parameter to change the security properties of a connection.

Purpose

To change the security properties of a connection. Put this parameter under the DESCRIPTION parameter.

Usage Notes

The parameters permitted under SECURITY are SSL_SERVER_CERT_DN and AUTHENTICATION_SERVICE.

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))
    (SECURITY=
      (SSL_SERVER_CERT_DN="cn=sales,cn=OracleContext,dc=us,dc=acme,dc=com")))

6.10.3 SSL_SERVER_CERT_DN

Use the SSL_SERVER_CERT_DN parameter to specify the distinguished name (DN) of the database server.

Purpose

To specify the distinguished name (DN) of the database server.

Usage Notes

The server DN must be known by the client ahead of time. Otherwise, the client cannot specify the server's DN in SSL_SERVER_CERT_DN. The client uses this information to obtain the list of DNs it expects for each of the servers, enforcing the database server DN to match its service name. This parameter must be set to the server DN (for example, SSL_SERVER_CERT_DN="finance, cn=OracleContext,c=us,o=example") to use full DN matching. For partial DN matching, do not include this parameter.

Use this parameter with the sqlnet.ora parameter SSL_SERVER_DN_MATCH to enable full DN matching.

Example

finance= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL = tcps) (HOST = finance)
     (PORT = 1575)))
   (CONNECT_DATA=
     (SERVICE_NAME=finance.us.example.com))
   (SECURITY=
     (SSL_SERVER_CERT_DN="cn=finance,cn=OracleContext,c=us,o=example")))

6.10.4 TOKEN_AUTH

Use the TOKEN_AUTH parameter to configure token-based authentication for Oracle Cloud Infrastructure (OCI) Identity and Access Management (IAM) or Microsoft Azure Active Directory (Azure AD) users on Oracle Autonomous Databases.

Purpose

To configure token-based authentication for IAM or Azure AD users on the Oracle Autonomous Database instances. This method enforces strong authentication, which enables users or services to use a token for a client connection.

Use this parameter under the SECURITY section of the tnsnames.ora file, sqlnet.ora file, or directly as part of the command-line connect string. The parameter value specified in the connect string takes precedence over the other specified values.

Usage Notes for IAM

  • An OCI IAM token (db-token) is a database access token with an expiration time. You can request this token from IAM using Oracle Cloud Infrastructure (OCI) Command Line Interface (CLI) or programmatically from the OCI Software Development Kit (SDK).

    You can use one of the IAM user credentials, such as API-key, security token, resource principal, instance principal, or delegation token to retrieve the db-token and private key from IAM.

  • OCI IAM tokens are transmitted over secure channels. You must use only the TCP/IP with Transport Layer Security (TLS) protocol, otherwise an error message appears indicating that non-TLS connections are disallowed.

  • When an IAM user logs in using /@connect_identifier, then the TOKEN_AUTH setting (TOKEN_AUTH=OCI_TOKEN) instructs the database client to get the db-token and private key files from either the default directory or the location specified by TOKEN_LOCATION.

    When an IAM user logs in using the IAM user name and IAM database password instead of /@connect_identifier, then the database client initiates the login without retrieving a token (using IAM database password authentication).

  • If your client application is updated to work with IAM, then you can override the TOKEN_AUTH setting. In this case, IAM directly passes the db-token and private key to the database client using the client API as attributes. When the client receives this request, the client signs the db-token with the private key and sends it to the database.

  • The general IAM token-based authentication process is as follows:

    1. An IAM user or application in OCI first requests the db-token from IAM by using API-key, security token, resource principal, instance principal, or delegation token (delegation token is available only in the Cloud Shell).

      To use a security token, you need to generate it by completing the browser authentication process and then request the db-token using that security token. If the IAM policy that authorizes you to be issued the db-token exists, then the db-token is returned.

      You request the db-token using OCI CLI (or OCI SDK for applications). For example, run the following OCI CLI command to request the db-token by using an API-key (apikey):

      $ oci iam db-token get --profile scott

      The profile flag specifies the profile for which you want to access the IAM user credentials and retrieve the db-token.

      For more information on using OCI CLI, see the get command details in Oracle Cloud Infrastructure CLI Command Reference.

    2. OCI CLI references the config file (that stores your IAM user credentials as part of the profile) and makes a call to IAM to get the db-token. The db-token and private key files are written at the default or specified token location.

      If an application is updated to work with IAM, then it directly passes the db-token and private key to the database client through the client API as attributes.

      You can specify the TOKEN_LOCATION parameter to override the default directory where the db-token and private key files are stored.

    3. The database client signs the db-token with the private key and sends it to the database. The database verifies the db-token, gets the group membership information for the user, and completes the login.

Table 6-1 Values and Examples for IAM

Default Value Example

None

TOKEN_AUTH=OCI_TOKEN

In the tnsnames.ora file:
net_service_name=
    (DESCRIPTION =
       (ADDRESS=(PROTOCOL=tcps)(HOST=sales-svr)(PORT=1521))
       (SECURITY=(SSL_SERVER_DN_MATCH=TRUE)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OCI_TOKEN))
       (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
     ) 
In the sqlnet.ora file:
TOKEN_AUTH=OCI_TOKEN

In these examples, the optional TOKEN_LOCATION parameter is not specified. Thus, the db-token and private key files are written at the default token location.

Usage Notes for Azure AD

  • An Azure AD OAuth2 access token is a bearer token with an expiration time and scope. This token follows the OAuth2.0 standard with Azure AD extensions. You can request these tokens from tools and scripts run on Linux, Microsoft PowerShell, or other environments. You can also request these tokens programmatically using the Microsoft SDKs.

  • When an Azure AD user logs in using /@connect_identifier, then the TOKEN_AUTH setting (TOKEN_AUTH=OAUTH) instructs the database client to get the access token from the directory location specified by TOKEN_LOCATION if the token file is named token. If the token file name is different from token, then you must use the file name along with the directory location while specifying the TOKEN_LOCATION parameter.

  • Bearer tokens are transmitted over secure channels. You must use only the TCP/IP with Transport Layer Security (TLS) protocol, otherwise an error message appears indicating that non-TLS connections are disallowed.

  • The general Azure AD token-based authentication process is as follows:
    1. An Azure AD user or application first requests the access token from Azure AD using one of the supported Microsoft Azure AD authentication flows (resource owner password credentials, authorization code, or client credentials).

      You can request these tokens from tools and scripts run on Linux, Microsoft PowerShell, or other environments. You can also request these programmatically using the Microsoft SDKs.

      • An Azure AD user can connect using any supported utility (such as PowerShell or Azure CLI) to retrieve the token and store it in a local file directory.

      • If your client application is updated to retrieve access tokens from Azure AD, then you can override the TOKEN_AUTH setting. In this case, the application can request the token directly from Azure AD and pass it through a database client API as an attribute.

      For detailed examples on how to retrieve an Azure AD OAuth2 access token, see Oracle Database Security Guide.

    2. The database client then sends the token to the database. The database verifies the token (using the Azure AD public key) and extracts various claims from the token, including user name, app roles, and audience. If the Azure AD principal is mapped to a database schema (exclusively or shared), then the login is completed.

Table 6-2 Values and Examples for Azure AD

Default Value Example

None

If the token file is named token:

TOKEN_AUTH=OAUTH TOKEN_LOCATION="token_file_directory"

  • In the tnsnames.ora file:
    net_service_name=
        (DESCRIPTION=
          (ADDRESS=(PROTOCOL=tcps)(HOST=salesserver1)(PORT=1522))
          (SECURITY=(SSL_SERVER_DN_MATCH=ON)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OAUTH)(TOKEN_LOCATION="/home/dbuser1/access-token"))
          (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
        )
    
  • In the sqlnet.ora file:
    TOKEN_AUTH=OAUTH 
    TOKEN_LOCATION="/home/dbuser1/access-token"
    

In these examples, the token file name is token. Thus, only the directory path (/home/dbuser1/access-token) is specified. The client automatically looks for the token file and gets the access token from the specified path.

If the token file name is different from token:

TOKEN_AUTH=OAUTH TOKEN_LOCATION="token_file_directory/token_filename"

  • In the tnsnames.ora file:
    net_service_name=
        (DESCRIPTION=
          (ADDRESS=(PROTOCOL=tcps)(HOST=salesserver1)(PORT=1522))
          (SECURITY=(SSL_SERVER_DN_MATCH=ON)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OAUTH)(TOKEN_LOCATION="/home/dbuser1/access-token/mytoken"))
          (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
        )
    
  • In the sqlnet.ora file:
    TOKEN_AUTH=OAUTH 
    TOKEN_LOCATION="/home/dbuser1/access-token/mytoken"
    

In these examples, the token file name is mytoken. Thus, both the file name and directory path (/home/dbuser1/access-token) are specified.

6.10.5 TOKEN_LOCATION

Use the TOKEN_LOCATION parameter to specify the token file directory. You use this parameter while configuring token-based authentication for Oracle Cloud Infrastructure (OCI) Identity and Access Management (IAM) or Microsoft Azure Active Directory (Azure AD) users on an Oracle Autonomous Database.

Purpose

To specify the directory location where token file is stored for token-based authentication.

Use this parameter along with the TOKEN_AUTH parameter in the tnsnames.ora file, sqlnet.ora file, or directly as part of the command-line connect string. The parameter values specified in the connect string take precedence over the other specified values.

Usage Notes for IAM

The TOKEN_LOCATION parameter is optional for IAM token-based authentication. You can use this parameter along with the TOKEN_AUTH parameter to override the default directory where the db-token and private key are stored. This location is used by the database client to retrieve the db-token and private key from IAM.

When an IAM user initiates a connection using /@connect_identifier, the database client retrieves the db-token and private key from either the default directory or the location specified by TOKEN_LOCATION, signs the db-token using the private key, and sends the db-token to the database.

Table 6-3 Values and Examples for IAM

Default Value Example

/home/username/.oci/db-token (on Linux)

TOKEN_LOCATION="token_file_directory"

In the tnsnames.ora file:
net_service_name=
    (DESCRIPTION =
       (ADDRESS=(PROTOCOL=tcps)(HOST=sales-svr)(PORT=1521))
       (SECURITY=(SSL_SERVER_DN_MATCH=TRUE)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OCI_TOKEN)(TOKEN_LOCATION="/home/dbuser1/.oci/db-token"))
       (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
     ) 
In the sqlnet.ora file:
TOKEN_AUTH=OCI_TOKEN
TOKEN_LOCATION="/home/dbuser1/.oci/db-token"

Usage Notes for Azure AD

The TOKEN_LOCATION parameter is mandatory for Azure AD token-based authentication. You must use this parameter along with the TOKEN_AUTH parameter to specify the directory location where the Azure AD OAuth2 access token is stored.

If your token file is named token, then specify only the directory path. If the token file name is different from token, then you must use the file name along with the directory path.

When an Azure AD user initiates a connection using /@connect_identifier, the database client retrieves the access token from the location specified by TOKEN_LOCATION and sends the token to the database server.

Table 6-4 Values and Examples for Azure AD

Default Value Example

None

If the token file is named token:

TOKEN_LOCATION="token_file_directory"

  • In the tnsnames.ora file:
    net_service_name=
        (DESCRIPTION=
          (ADDRESS=(PROTOCOL=tcps)(HOST=salesserver1)(PORT=1522))
          (SECURITY=(SSL_SERVER_DN_MATCH=ON)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OAUTH)(TOKEN_LOCATION="/home/dbuser1/access-token"))
          (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
        )
    
  • In the sqlnet.ora file:
    TOKEN_AUTH=OAUTH 
    TOKEN_LOCATION="/home/dbuser1/access-token"
    

In these examples, the token file name is token. Thus, only the directory path (/home/dbuser1/access-token) is specified. The client automatically looks for the token file and gets the access token from the specified path.

If the token file name is different from token:

TOKEN_LOCATION="token_file_directory/token_filename"

  • In the tnsnames.ora file:
    net_service_name=
        (DESCRIPTION=
          (ADDRESS=(PROTOCOL=tcps)(HOST=salesserver1)(PORT=1522))
          (SECURITY=(SSL_SERVER_DN_MATCH=ON)(SSL_SERVER_CERT_DN="C=US,O=example,CN=OracleContext")(TOKEN_AUTH=OAUTH)(TOKEN_LOCATION="/home/dbuser1/access-token/mytoken"))
          (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
        )
    
  • In the sqlnet.ora file:
    TOKEN_AUTH=OAUTH 
    TOKEN_LOCATION="/home/dbuser1/access-token/mytoken"
    

In these examples, the token file name is mytoken. Thus, both the file name and directory path (/home/dbuser1/access-token) are specified.

6.11 Timeout Parameters

The timeout section of the tnsnames.ora file provides the ability to specify timeout and retry configuration through the TNS connect string.

The following parameters can be set at the DESCRIPTION level of a connect string:

6.11.1 CONNECT_TIMEOUT

Purpose

To specify the timeout duration in ms, sec, or min for a client to establish an Oracle Net connection to an Oracle database.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

The timeout interval specified by CONNECT_TIMEOUT is a superset of the TCP connect timeout interval. It includes the time to be connected to the database instance providing the requested service, not just the duration of the TCP connection. It accepts different timeouts with or without space between the value and the unit. In case, no unit is mentioned, the default unit is sec.

The timeout interval is applicable for each ADDRESS in an ADDRESS_LIST, and each IP address to which a host name is mapped.

The CONNECT_TIMEOUT parameter is equivalent to the sqlnet.ora parameter SQLNET.OUTBOUND_CONNECT_TIMEOUT, and overrides it.

Example

net_service_name=
 (DESCRIPTION= 
  (CONNECT_TIMEOUT=10 ms)(RETRY_COUNT=3)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
   (SERVICE_NAME=sales.us.example.com)))

6.11.2 RETRY_COUNT

Purpose

To specify the number of times an ADDRESS list is traversed before the connection attempt is terminated.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

When a DESCRIPTION_LIST is specified, each DESCRIPTION is traversed multiple times based on the specified number of retries.

Example

net_service_name= 
(DESCRIPTION_LIST=
 (DESCRIPTION=
  (CONNECT_TIMEOUT=10)(RETRY_COUNT=3)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales1.example.com)))
 (DESCRIPTION=
  (CONNECT_TIMEOUT=60)(RETRY_COUNT=1)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales2.us.example.com))))

6.11.3 RETRY_DELAY

Purpose

To specify the delay in seconds between subsequent retries for a connection. This parameter works in conjunction with RETRY_COUNT parameter.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

When a DESCRIPTION_LIST is specified, each DESCRIPTION is traversed multiple times based on the specified number of retries, and the specific delay for the description.

Example

net_service_name= 
(DESCRIPTION_LIST=
 (DESCRIPTION=
  (CONNECT_TIMEOUT=10)(RETRY_COUNT=3)(RETRY_DELAY=2)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales1.example.com)))
 (DESCRIPTION=
  (CONNECT_TIMEOUT=60)(RETRY_COUNT=2)(RETRY_DELAY=1)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales2.us.example.com))))

6.11.4 TRANSPORT_CONNECT_TIMEOUT

Purpose

To specify the transport connect timeout duration in ms, sec, or min for a client to establish an Oracle Net connection to an Oracle database.

Usage Notes

This parameter is put under the DESCRIPTION parameter.

The TRANSPORT_CONNECT_TIMEOUT parameter specifies the time, in ms, sec, or min, for a client to establish a TCP connection to the database server. It accepts different timeouts with or without space between the value and the unit. The default value is 60 seconds. In case, no unit is mentioned, the default unit is sec.

The timeout interval is applicable for each ADDRESS in an ADDRESS_LIST description, and each IP address that a host name is mapped. The TRANSPORT_CONNECT_TIMEOUT parameter is equivalent to the sqlnet.ora parameter TCP.CONNECT_TIMEOUT, and overrides it.

Example

net_service_name =
  (DESCRIPTION=
    (TRANSPORT_CONNECT_TIMEOUT=10 ms)
    (ADDRESS_LIST=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
    (CONNECT_DATA=
      (SERVICE_NAME=sales.us.example.com)))

6.11.5 RECV_TIMEOUT

Use the tnsnames.ora parameter RECV_TIMEOUT to specify the duration of time that a database client or server should wait for data from a peer after establishing a connection.

Purpose

To specify the time, in ms, sec, or min, for a database client or server to wait for data from the peer after establishing a connection. The peer must send data within the time interval that you specify.

You can specify the time in hours, minutes, seconds, or milliseconds by using the hr, min, sec, or ms keyword respectively. If you do not specify a unit of measurement, then the default unit is sec.

Usage Notes

This parameter is put under the DESCRIPTION parameter.

Setting this parameter for clients ensures that receive operations are not left in a wait state indefinitely or for a long period due to server host being down, server busy state, or network connectivity issues. If a client does not receive response data in the time specified, then the client logs ORA-12535: TNS:operation timed out and ORA-12609: TNS: Receive timeout occurred messages to the sqlnet.log file.

Default Value

None

Minimum Value

1 ms

Recommended Value

Any number greater than the minimum value of 1 ms up to 4294967295 ms.

Example

RECV_TIMEOUT=10ms

or

RECV_TIMEOUT=10 ms

6.12 Compression Parameters

The compression section of the tnsnames.ora file provides the ability to enable compression and specify compression levels. These parameters can be set at the DESCRIPTION level of a connect string.

6.12.1 COMPRESSION

The tnsnames.ora file’s compression parameter enables or disables the data compression.

Purpose

To enable or disable data compression.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

Setting this parameter in the connect descriptor for a client overrides the SQLNET.COMPRESSION parameter in the client-side sqlnet.ora file.

Default

off

Values

  • on to enable data compression.

  • off to disable data compression.

Example

net_service_name=
 (DESCRIPTION=
   (COMPRESSION=on)
      (ADDRESS_LIST=
         (ADDRESS= (PROTOCOL=tcp) (HOST=sales1-server) (PORT=1521))
         (ADDRESS= (PROTOCOL=tcp) (HOST=sales2-server) (PORT=1521)))
   (CONNECT_DATA=
       (SERVICE_NAME=sales.us.example.com)))

Related Topics

6.12.2 COMPRESSION_LEVELS

The COMPRESSION_LEVELS parameter of the tnsnames.ora file specifies the compression level.

Purpose

To specify the compression level.

Usage Notes

The compression levels are used at the time of negotiation to verify which levels are used at both ends, and select one level. Put this parameter under the DESCRIPTION parameter.

This parameter is used with the COMPRESSION parameter. Setting this parameter in the connect descriptor for a client overrides the SQLNET.COMPRESSION_LEVELS parameter in the client-side sqlnet.ora file.

Default

low

Values

  • low for low CPU usage and a low compression ratio.

  • high for high CPU usage and a high compression ratio.

Example

net_service_name=
 (DESCRIPTION=
  (COMPRESSION=on)
  (COMPRESSION_LEVELS=(LEVEL=low)(LEVEL=high))
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)))

Related Topics