Remote Servers

Use sp_addserver to add entries to the sysservers table for the local server and for each remote server that is to be called.

The syntax is:

sp_addserver server_name [, server_class [, network_name]]

where:

server_name – is a unique name used to identify the server.
server_class – is the type of server. The supported server classes with the types of servers that are in each class are described in the following sections. The default is server class ASEnterprise.

Note: Component Integration Services does not support server class db2.
network_name – is the server name in the interfaces file. This name may be the same as server_name, or it may differ. The network_name is sometimes referred to as the physical name. The default is the same name as server_name.

Note: You need the same sort order and case sensitivity between servers.

The server classes are:

ASEnterprise – SAP ASE uses server class ASEnterprise. When Component Integration Services first establishes a connection to a server in this class, Component Integration Services determines the SAP ASE version and establishes server capabilities based on the version found.
ASAnywhere – a server with server class ASAnywhere is an instance of SQL Anywhere. The version must be SQL Anywhere 9.0 or later.
ASIQ – a server with server class ASIQ is SAP IQ version 12.5 or later
direct_connect – server with server class direct_connectis an Open Server-based application that conforms to the direct_connect interface specification

Open Server-based applications using server class direct_connect are the preferred means of accessing all external, non-SAP data sources.

SAP ASE with Component Integration Services enables interacts with clients and Open Server-based applications. For example, a client application interacts with CIS on SAP ASE, which interacts through the network to a DirectConnect, such as Oracle or Informix. The DirectConnect can also have direct access to the client application, and the client application to the DirectConnect.
sds – server with server class sds conforms to the interface requirements of a Specialty Data Store™ as described in the Adaptive Server Specialty Data Store Developer’s Kit manual. A Specialty Data Store is an Open Server application you design to interface with SAP ASE.
RPCServer – a server configured with RPCServer is not capable of handling anything other than RPCs. Servers in this class cannot participate in distributed transactions, and Component Integration Services does not attempt to send SQL statements to a server configured with this class.

To send RPCs to Backup Server or to XP Server, the sp_serveroption negotiated logins and server logins must be enabled.

Typically, servers in this class are customer-written Open Server applications intended to either perform a customized operation, or to make data available to an SAP ASE application that is generated as a result of one or more RPCs. The only Open Server event handlers required for this type of application are:
- SRV_CONNECT – handle and authenticate a login request from CIS or client application.
- SRV_DISCONNECT – handle disconnect request from CIS or client application.
- SRV_ATTENTION – handle CANCEL request from CIS or client application.
- SRV_RPC – handle RPC from CIS. The handling of the RPC may produce a result set, which CIS will forward to the ASE client on whose behalf CIS forwarded the RPC.
Using this server class, it is possible to write an Open Server application that supports CIS proxy tables that map to RPC's:
```
create existing table myRPCtable
      (
            <column description(s)
      )
      external procedure at 'myRpcServerName...rpcname'
```

Connection Management
When connecting to a remote server on behalf of a client, Component Integration Services uses Client-Library functions.
Connecting to Remote Servers Without the Interfaces File
You can establish a connection to remote servers without using corresponding entries in directory services ldap or interfaces files.
LDAP Directory Services
You can use the LDAP directory services instead of the interfaces file in both the client and the server.
Secure Communication with SSL
Using SSL, you can establish secure connections from Component Integration Services to any number of remote servers that support the SSL protocol (SAP ASE and some DirectConnects).
Secure Communication Using Kerberos
Kerberos network-based authentication is a single sign on feature which allows Kerberos clients authenticated with Kerberos system, to be able to connect to any application that supports Kerberos authentication. With one centralized password stored, you need not specify a password to connect to an application that supports Kerberos.
Security Issues
When establishing a connection to a remote SAP ASE, Client-Library functions are used instead of a site handler when either cis_rpc_handling or set transactional_rpc is on.
Remote Server Logins
To fully support remote logins, Client-Library provides connection properties that enable Component Integration Services to request a server connection.
Mapping External Logins
SAP ASE users who invoke Component Integration Services require login names and passwords to remote servers.
Configuring Failover for Remote Server Connections
If the interfaces file (or LDAP directory service) is set up to define a failover configuration, then Component Integration Services takes advantage of it by automatically failing over connections to the failover server if a connection to the primary server fails.
Remote Server Capabilities
The first time SAP ASE establishes a connection to a remote server of class sds or direct_connect, it issues an RPC named sp_capabilities and expects a result set in return.

Parent topic: Component Integration Services Concepts