The following groups of parameters provide information about using DB2 in a client/server environment:
You can use the following parameters to configure your database clients and database servers:
This parameter allows you to assign a unique name to the database instance on a workstation in the NetBIOS LAN environment. This nname is the basis for the actual NetBIOS names that will be registered with NetBIOS for a workstation.
Since the NetBIOS protocol establishes connections using these NetBIOS names, the nname parameter must be set for both the client and server.
Client applications must know the nname of the server that contains the database to be accessed. The server's nname must be cataloged in the client's node directory as the "server-nname" parameter using the CATALOG NETBIOS NODE command.
If nname at the server node changes to a new name, all clients accessing databases on that server must catalog this new name for the server.
This parameter contains the name of the TCP/IP port which a database server will use to await communications from remote client nodes. This name must be the first of two consecutive ports reserved for use by the database manager; the second port is used to handle interrupt requests from down-level clients.
In order to accept connection requests from a database client using TCP/IP, the database server must be listening on a port designated to that server. The system administrator for the database server must reserve a port (number n) and define its associated TCP/IP service name in the services file at the server. If the database server needs to support requests from down-level clients, a second port (number n+1, for interrupt requests) needs to be defined in the services file at the server.
The database server port (number n) and its TCP/IP service name need to be defined in the services file on the database client. Down-level clients also require the interrupt port (number n+1) to be defined in the client's services file.
The location of the services file depends on your operating environment. For example:
The svcename parameter should be set to the service name associated with the main connection port so that when the database server is started, it can determine on which port to listen for incoming connection requests. If you are supporting or using a down-level client, the service name for the interrupt port is not saved in the configuration file. The interrupt port number can be derived based on the main connection port number (interrupt port number = main connection port + 1).
Refer to the Installation and Configuration Supplement for more information about setting up TCP/IP for database servers.
This parameter defines the name of the remote transaction program that the database client must use when it issues an allocate request to the database serverwhen using the APPC communication protocol. This parameter must be set in the configuration file at the database server.
This parameter must be the same as the transaction program name that is configured in the SNA transaction program definition. Refer to the Installation and Configuration Supplement for more information about setting up APPC for your DB2 product.
Recommendation: The only accepted characters for use in this name are:
This parameter specifies the name of the NetWare** fileserver where the internetwork address of the database manager is registered. The internetwork address of the database manager is stored in the bindery at the NetWare file server. If the registered fileserver name changes, all clients that access the server instance must:
For more information, refer to the Installation and Configuration Supplement.
This parameter provides the name of the database manager instance in an IPX/SPX network. Each server instance registered to a NetWare fileserver must have a unique name. If this name changes at the database server, all clients that access the server must uncatalog the server node and recatalog it again, specifying the new object name.
This parameter specifies a "well-known" socket number and represents the connection end point in a DB2 server's internetwork address. The socket number must be unique for each DB2 server instance on a given machine, and unique among all Novell** IPX/SPX applications running on this same machine. This is to guarantee that the DB2 server is able to listen to incoming IPX/SPX connections using this socket number.
You can use the following parameters to configure your database clients and database servers to make use of DCE Directory services:
For information about how DB2 uses DCE directories, refer to "Using Distributed Computing Environment (DCE) Directory Services" in Administration Guide: Planning.
This parameter indicates whether or not DCE directory services is used.
If this parameter is set to NONE, only local directory files will be searched for the target of the CONNECT or ATTACH requests. However, you can still use the dir_path_name and dir_obj_name parameters to record the name of your database instance and databases in the DCE namespace.
If this parameter is set to DCE, then when an application running within this database manager instance cannot find the target of its CONNECT or ATTACH requests, the DCE directory will be searched.
For the numeric equivalents and API constants for these values, refer to the Administrative API Reference.
The unique name of the database manager instance in the global namespace is made up of this value and the value in the dir_obj_name parameter.
All client applications running within this instance also use it as the default path name for their CONNECT or ATTACH requests, unless it is overridden by the value of the DB2DIRPATHNAME environment variable.
Recommendation: Use the name provided by your DCE administrator.
The object name representing your database manager instance (or your database) in the directory. The concatenation of this value and the dir_path_name value yields a global name that uniquely identifies the database manager instance or database in the namespace governed by the directory services specified in the dir_type parameter.
This parameter is only meaningful if the dir_path_name parameter is specified.
The total length of the configuration parameters dir_path_name and dir_obj_name must be less than 255 characters.
Recommendation: Refer to "Using Distributed Computing Environment (DCE) Directory Services" in the Administration Guide: Implementation for more information.
This parameter specifies the name of the default routing information object entry that will be used by all client applications attempting to access a DRDA server. It applies to OS/2 and UNIX-based environments only.
If the value of this parameter starts with /.:/ or /.../, then the value will be used as is. Otherwise, it will be appended to the dir_path_name parameter (or DB2DIRPATHNAME environment variable) value to form the full name of the routing information object.
You can use the environment variable DB2ROUTE to override this default.
This parameter is only meaningful if the dir_type parameter is set to DCE.
Recommendation: Refer to "Using Distributed Computing Environment (DCE) Directory Services" in the Administration Guide: Implementation for more information.
This parameter indicates the communication protocols that the client applications on this instance can use for remote connections. Its content is a character string, made up of one or more tokens. If you are specifying more than one token, separate them with a comma. The order of the tokens is significant in terms of preference.
This parameter can only be used with DCE, and applies to OS/2 and UNIX-based environments only.
You can temporarily override the value of this parameter by setting the DB2CLIENTCOMM environment variable.
If the value of this parameter is NULL and the environment variable has not been set, the first protocol specified in the server's global directory object is used.
This parameter is ignored if dir_type is set to NONE.
Recommendation: The protocol that is used most often should be specified first.
This parameter defines the default client adapter number for the NETBIOS protocol whose server nname is extracted from DCE Cell Directory Services (CDS). This parameter is applicable to the OS/2 environment only.
This parameter can only be used with DCE.
You can temporarily override the value of this parameter by setting the DB2CLIENTADPT environment variable. If this environment variable contains a non-numeric or out-of-range number, adapter number 0 (zero) is used.
You can use the following parameters to establish DB2 Discovery:
This parameter is used to prevent information about a database from being returned to a client when a discovery request is received at the server.
The default for this parameter is that discovery is enabled for this database.
By changing this parameter value to "Disable", it is possible to hide databases with sensitive data from the discovery process. This can be done in addition to other database security controls on the database.
For the numeric equivalents and API constants for these values, refer to the Administrative API Reference.
From an administration server perspective, this configuration parameter determines the type of discovery mode that is started when DB2ADMIN starts.
From a server instance perspective, if discover = DISABLE then the information for this server instance is essentially hidden from clients. The administration server will not package information about this instance when a known discovery request is issued against this system by any client.
From a client perspective, one of the following will occur:
The default discovery mode is SEARCH.
For the numeric equivalents and API constants for these values, refer to the Administrative API Reference.
For more information on DB2 Discovery, refer to the Quick Beginnings manual appropriate to your platform.
From an administration server perspective this parameter defines the search discovery managers that are started when DB2ADMIN starts. These managers service search discovery requests from clients.
| Note: | The protocols defined in discover_comm must also be specified in the DB2COMM registry variable. |
From a client perspective, this parameter defines the protocols that clients use to issue search discovery requests.
More than one protocol may be specified, separated by commas; or, the parameter may be left blank.
The default for this parameter is "None" meaning that there are no search discovery communications protocols.
This parameter specifies whether this instance can be detected by DB2 Discovery. The default, "enable", specifies that the instance can be detected, while "disable" prevents the instance from being discovered.
For the numeric equivalents and API constants for these values, refer to the Administrative API Reference.
For more information on DB2 Discovery, refer to the Quick Beginnings manual appropriate to your platform.