create connection

Description

Examples

Example 1

Creates a connection for the pubs2 database in the SYDNEY_DS data server. Replication Server will use the ansi_error error class to handle errors for the database. It will use the function strings in the sqlserver_derived_class function string class for data manipulation operations. The connection will use the pubs2_maint login name with the password pubs2_maint_ps to log into the pubs2 database:

create connection to SYDNEY_DS.pubs2
 set error class ansi_error
 set function string class sqlserver_derived_class
 set username pubs2_maint
 set password pubs2_maint_pw

Example 2

Creates a connection similar to the first example. However, in this example, the tokyo_rs_error Replication Server error class handles the Replication Server errors for the connection and the with log transfer clause is specified. This allows the connection to accept input from a RepAgent. The connection is with a database that contains primary data or that will be a source of replicated functions:

create connection to TOKYO_DS.pubs2
set error class ansi_error
set function string class sqlserver_derived_class
set username pubs2_maint
set password pubs2_maint_pw 
set replication server error class tokyo_rs_error
with log transfer on

Usage

• Use create connection to add a database to the replication system. Normally, you use this command to add connections to non-Sybase databases. To create a standard connection with an Adaptive Server database, use Sybase Central or rs_init.

• To create a connection that uses heterogeneous datatype support (HDS) to translate datatypes from the primary to the replicate database, you can also use scripts provided by Sybase that both create the connection and install HDS. See the Replication Server Configuration Guide for your platform for instructions.

• Execute create connection at the Replication Server that manages the database.

• Replication Server distributes database connection information to qualifying sites through out the replication system. The changes do not appear immediately at all sites because of normal replication system lag time.

• You must specify an error class, even if you use the default error class: rs_sqlserver_error_class.

• You do not have to specify a Replication Server error class unless it is a new Replication Server error class. The default Replication Server error class is rs_repserver_error_class.

• Only one connection is allowed per database. This is enforced by the ID Server, which registers each database in its rs_idnames system table. The ID Server must be available when you create a connection for a database.

• Use set function string class [to] function_class to activate class-level translations for non-Sybase data servers.

• Replication Server configuration parameters are stored in the rs_config system table. See the Replication Server Administration Guide Volume 1 for more information about the database connection parameters in the rs_config system table.

• See the Replication Server Administration Guide Volume 2 for more information about configuring parallel DSI threads.

• Use assign action to enable retry of transactions that fail due to specific data server errors.

• Before setting dump_load to “on,” create function strings for the rs_dumpdb and rs_dumptran functions. Replication Server does not generate function strings for these functions in the system-provided classes or in derived classes that inherit from these classes.

• Set save_interval to save transactions in the DSI queue that can be used to resynchronize a database after it has been restored from backups. Setting a save interval is also useful when you set up a warm standby of a database that holds replicate data or receives replicated functions. You can use sysadmin restore_dsi_saved_segments to restore backlogged transactions.

• You specify the maintenance user login name and password when creating the connection. The maintenance user login name must be granted all necessary permissions to maintain replicated data in the database.

• To create a logical connection for a warm standby application, use create logical connection.

• In a warm standby application, the connections for the active database and the standby database must have log transfer on.

• The function-string class for a database in a warm standby application is used only when the database is the active database. Replication Server uses rs_default_function_class for the standby database.

• Use alter connection to change the attributes of a connection.

• If the password of the maintenance user has been changed, use alter connection to enter the new password.

• Both ends of a connection must use compatible Security Control Layer (SCL) drivers with the same security mechanisms and security features. The remote server must support the set proxy or equivalent command. It is the replication system Administrator’s responsibility to choose and set security features for each server. The Replication Server does not query the security features of remote servers before attempting to establish a connection. Connections fail if security features at both ends of the connection are not compatible.

• create connection specifies security settings for an outgoing connection from Replication Server to a target data server. Security features set by create connection override those set by configure replication server.

• If unified_login is set to “required,” only the replication system Administrator with “sa” permission can log in to the Replication Server without a credential. If the security mechanism should fail, the replication system Administrator can log in to Replication Server with a password and disable unified_login.

• A Replication Server can have more than one security mechanism; each supported mechanism is listed in the libtcl.cfg file under SECURITY.

• Message encryption is a costly process with severe performance penalties. In most instances, it is wise to set msg_confidentiality to “required” only for certain connections. Alternatively, choose a less costly security feature, such as msg_integrity.

Permissions

create connection requires “sa” permission.

See also