QMNet

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QMNet uses the QMClient interface to provide an extension to the QM file system allowing network access to files on another QM system. Unlike use of NFS or mapped network drives, QMNet provides locking of remote records, ensuring that data integrity can be maintained on distributed data.

 

Two steps are necessary to use QMNet. Firstly, the server must be defined, mapping the server name to a network address, user name and password. Secondly, the remote file must be defined using a Q-type VOC record.

 

 

Defining the Server

 

The remote server is defined using the SET.SERVER command. This can only be executed by users with administrative rights in the QMSYS account.

 

The command is

 

SET.SERVER name  address  user.name  password

 

where

 

nameis the name to be given to the server. This must consist of letters, numbers, periods and hyphens only and will be mapped to uppercase internally.

 

addressis the IP address or server name of the remote server. If the remote server uses a non-standard port number for QMClient access, the port number should be included, separated from the IP address by a colon (e.g. 193.118.13.48:4229).

 

user.nameis the login name to be used on the remote system.

 

passwordis the password for the specified user.

 

The remote server must have remote access enabled by setting the NETFILES configuration parameter to 2.

 

 

Defining the Remote File

 

Each remote file is defined by an extended form of the Q-type VOC entry where field 4 contains the name of the server.

 

Once the file has been defined, it may be accessed by programs in the same way as a local file. The following restrictions apply to access from QMBasic programs:

The OPENSEQ statement and related sequential file access operations are not supported.
Access to remote files inside transactions will be non-transactional.
The FILEINFO() function will return the file type as FL$TYPE.NET (6). Some modes of FILEINFO() are not supported.
A maximum of 10 servers may be accessed at one time by any one QM process. There is no practical limit to the number of files that may be open on each server.

 

 

Listing Server Definitions

 

A list of all defined QMNet servers can be displayed using the LIST.SERVERS command. This can only be executed by users with administrative rights in the QMSYS account.

 

The command is

 

LIST.SERVERS

 

 

 

Deleting a Server Definition

 

The definition for a remote server may be deleted using the DELETE.SERVER command. This can only be executed by users with administrative rights in the QMSYS account.

 

The command is

 

DELETE.SERVER name

 

where

 

nameis the name of the server.