An important feature when using Ingres is the node (vnode). This is where the Ingres/Net module is active.
The vnode allows you to settle the parameters for Ingres to connect to Ingres installation. This concept supports the implementation of a client/server environment. The client is often represented by PC with a Windows GUI and the server is a machine on which the database is installed and data are stored.
- A node contains the following information:
- A name: free format, except on exceptional circumstances (installation password).
- User: User must be declared on the target machine.
- Password: password of the user.
- Address: IP address or machine name.
- Protocol: wintcp, tcp_ip, etc.
- A listen address: is the installation code of Ingres remote installation (see ingprenv II_INSTALLATION.
In the case that there are several triplets address/protocol /listen address, Ingres will connect to the first, then the second in the event of failure, and so on. This is how high availability is implemented (either because there are several Ingres/Net connectors started on the server or in the case where data are replicated on different machines in real time by Ingres/Replicator.
A node can be global or local, where global supports the fact that the configuration of Ingres/Net is common to all users of a machine and where local concerns only the user who has been updated.
Managing the nodes
The update tool is called netutil, you will find it in the following screen independent from the platform used (Windows, Linux, Unix or VMS).
Common errors and bugs.
Once the node created proceed to some testing. If the test fails, it is usually due to one of the following:
- The user does not exist on the target machine (in the OS).
- The password is incorrect.
- The machine as you have specified does not exist (ping machine does not respond).
- Code installation (listen address) specified is not correct.
- Installation target is not started.
- Passwords management by Ingres of the target machine requires running the command mkvalidpwd (you must be root).
A password installation is a concept endemic to Ingres. In layman's term the DBA on the target machine will allows or not other DBA to connect to its installation (to be more precise it is a node that has specific properties).
On server side
- node name: must be same to the name of the machine (uname-n)
- password: Free
On client side:
- name of the node: name server target
- password: the one declared on the node must be same as the one on server
- address: IP address or name of the server machine
- listen address: II_INSTALLATION server side
when the node will be called by user from the client which will be use to connect to Ingres. It must be stated in Ingres (see the accessdb) and but doesn't need not exist on the target OS.
Making use of the node.
- To connect to an Ingres locally, use the command:
- To activate the node, the syntax is: