During the start-up process for each client, once the configuration file has been read, the Client/Server Binding searches for a file called mfcsovrd.cfg. It searches for this file in the system log file directory. If the file is found, its contents are used to override any parameters previously set up using the configuration file. The format of the override file is identical to that of the standard configuration file with the exception of a single additional entry, override-cntrl. This entry is used to indicate the subject of the override which may be a server name or a tag-name. If a server name is specified, any clients using that server have their parameters modified by the contents of the override file. If a tag-name is specified, only those clients using the specified tag-name have their parameters altered.
The client override facility can be used, for example, if a server is unavailable and applications need to be run on another machine. You could of course change the individual configuration files, but a single override file can be used to re-route any number of applications.
The override facility can also be used on the server, but in this case the server machine needs to be up and running. As before, either server names or tag-names can be overridden.
An entry is added to the log file whenever an override file is detected, and all parameters which are subject to the override process are logged.
The following example shows how the override facility can be used to re-route clients to another server:
[override-cntrl] override=servername [oldserver] servername=newserver
In this example the [override-cntrl] section specifies that the subject of the override is a server name (override=servername) and then, under the the old server name ([oldserver]), the new server name (servername=newserver) is specified. This would result in the following log file entries:
20/04/1998 11:01:02 Using Local File: mfcsovrd.cfg Overriding Entries for Servername:OLDSERVER servername=newserver 20/04/1998 11:01:02 Override Completed:
The following example shows how the override facility can be used to override the server being used by all those clients which are using a specified tag:
[override-cntrl] override=tagname [mf-clisrv] servername=newserv
In this example the [override-cntrl] section specifies that the subject of the override is a tag-name (override=tagname) and then, under the tag-name ([mf-clisrv]), the parameter to be overridden (in this case the server name) is specified (servername=newserv). This would result in the following log file entries:
20/04/1998 11:04:02 Using Local File: mfcsovrd.cfg Overriding Entries for Tagname:MF-CLISRV servername=newserv 20/04/1998 11:04:02 Override Completed: