Establishing Communications

This chapter contains the following topics:

• An overview of the process of creating connection data entries and authorizing user access to Ingres using virtual nodes (vnodes)
• An overview of the tables and menu of the forms-based Net Management Utility (netutil) startup screen
• Procedures for establishing and maintaining connections to remote Ingres instances using the following tools:
  • Netutil
  • The non-interactive mode of netutil
  • Network Utility and Visual DBA

How User Access Is Established

For users to be able to access Ingres, the following two steps are required:

1. The system administrator sets up accounts for local users, and for those remote users who access the local instance through a local account. This step is optional if an Installation Password is defined, in which case users access Ingres directly, without going through a local account. The system administrator can do this either before or after the installation procedure.

   Note: During installation, the installation owner user ID is defined. This account belongs to the Ingres administrator and is automatically authorized with maximum Ingres privileges that allow this user to perform all operations. Other user accounts can be set up after Ingres is installed.

2. After Ingres is running and the accounts are set up, the system administrator or database administrator uses Visual DBA or the create user statement to authorize the accounts that use this Ingres instance. For more information about this procedure, see the Database Administrator Guide.

Requirements for Accessing Remote Instances

When the instance includes Ingres Net, users can connect to databases on remote instances as well as those on their local instance. To connect to remote instances, the following requirements must be met:

• A virtual node (vnode) name must be defined for each remote instance that is accessed, unless you use the dynamic vnode format to connect.

  A virtual node (vnode) is a name defined on the local instance that points to the connection data and authorization data necessary to access a particular remote instance. When a user on the local node wants to access a database on a remote instance or run an application that accesses a database on a remote instance, the user must specify the vnode name for the instance in addition to the name of the database.

  The vnode name can be the same as the node's real address or node name. However, because the real names or addresses are often difficult to remember, and because there can be more than one instance on the node, other names are typically chosen for vnode names.

• A connection data entry must be defined for each remote instance that is accessed.

  A connection data entry contains the information necessary for Ingres Net to locate and connect to an instance on a remote node. A connection data entry is typically associated with a particular, locally defined vnode, but can also be specified dynamically with the dynamic vnode format. It includes the name or address of the node on which the remote instance resides, the listen address of the remote instance, and an Ingres keyword for the network protocol used between the local and remote nodes.

• Remote user authorizations must be defined for each remote instance that is accessed.

  A remote user authorization contains the login and password information necessary to gain access to a remote instance. It is typically associated with a particular, locally defined vnode, but can also be specified dynamically with the dynamic vnode format.

  Note: It is not necessary for a particular user ID to be defined as an operating system account on an instance's host machine to be a valid Ingres user on that instance. An account on a remote node can be authorized in exactly the same way as an account on the local node. Provided an Installation Password has been defined locally, the remote account can then access the instance directly without having to go through a local account.

  Instructions for defining an Installation Password for the local instance are provided later in this chapter. For the differences between these two types of passwords, see Remote User Authorizations.

Requirements for Accessing Distributed Databases

Just as a local DBMS Server accesses a local database, a Star server (part of the Ingres Star product) accesses a distributed database. When one or more of the databases that make up the distributed database reside on separate instances, Ingres Star uses Ingres Net. To use Ingres Star across Ingres Net, vnodes (with their corresponding connection data entries and remote user authorizations) must be defined on the Star server instance for each of the remote instances containing the databases that make up the distributed database.

If the connection data entries and the remote user authorizations are defined as private, connection data entries and remote user authorizations must also be defined for the installation owner (or the system administrator). These definitions are used if a distributed transaction fails. The Star Server attempts to recover the transaction as the owner of the Ingres Star instance.

Access Tools for Defining Vnodes

You define vnode names and their corresponding connection data entries and remote user authorizations using one of these tools:

• Net Management Utility (netutil)
• Network Utility (ingnet)
• Visual DBA.

Not all tools are available on all platforms.

Note: The Network Utility (if supported on your platform) is the preferred means of creating vnodes in Ingres.

To access the Network Utility

Windows and UNIX Environments that Support Ingres Visual Tools:

Use one of the following ways:

• Choose Start, Programs, Ingres, Network Utility.
• From Ingres Visual Manager, choose File, Run, Ingres Network Utility or select the Network Utility toolbar button.
• Enter ingnet on the command line.

To access Visual DBA

Use one of the following ways:

• Choose Start, Programs, Ingres, Visual DBA, or right-click the Ingres installation icon in the Windows status bar and choose Visual DBA.
• From Ingres Visual Manager, choose File, Run, Ingres Visual DBA or select the Visual DBA toolbar button.
• Enter vdba on the command line. For the required command syntax, see the Command Reference Guide.

To access netutil

Enter netutil on the command line. For the required command syntax, see the Command Reference Guide.

VMS and UNIX Environments that Do Not Support Ingres Visual Tools: Enter netutil on the command line. For the required command syntax, see the Command Reference Guide.

When Ingres and Ingres tools are installed as a cluster installation, it is necessary to run netutil from only one node to set up connection data entries and remote user authorizations for all of the nodes in the cluster.