HP XC System Software Administration Guide Version 4.0

The head node is the golden client, and only one golden client is supported. Each script in this
directory is executed unconditionally during the sconfigure process. The sconfigure scripts
return 0 (zero) on success and return a nonzero value on failures. You can stop the configuration
process on a nonrecoverable sconfigure error, which is indicated by the sconfigure script
exiting with a return code of 255. Alternatively, you can use config_die( ) in
ConfigUtils.pm to return 255. Any exit code other than 255 continues with the configuration
process.
The sconfigure scripts can include a user interface to aid in configuration and to suggest more
optimal configuration choices to the user.
The sunconfigure action is not performed automatically.
4.6.5.2 The gconfigure Scripts
The gconfigure scripts in the /opt/hptc/etc/gconfig.d directory modify the golden
image and set up client-to-server assignments and other global service configuration. A
gconfigure script often modifies global configuration files and modifies the database to include
client/server relationships for services.
The gconfigure action occurs only if one or more servers have been assigned the service. Thus,
gconfigure scripts are executed conditionally.
The gconfigure scripts return 0 (zero) on success and return a nonzero value on failures. You
can stop the configuration process on a nonrecoverable gconfigure error, which is indicated
by the gconfigure script exiting with a return code of 255. Alternatively, you can use
(config_die) in ConfigUtils.pm to return 255. Any exit code other than 255 will continue
with the configuration process.
A gconfigure script can have a user interface to aid in configuration and can suggest more
optimal configuration choices.
A gconfigure script is executed inside the cluster_config utility as follows:
script_path gconfigure server1 server2 server3 ...
script_path gunconfigure server1 server2 server3 ...
script_path gunconfigure
Combining the gunconfigure server with a server list unconfigures the specified nodes as
servers for the service, but the service will still be active in the system (on other nodes). Server
lists are derived from the servers specified during role assignment within the cluster_config
utility. A gunconfigure script with no server list means that the service is being entirely
unconfigured and will not be part of the new configuration being performed. The gunconfigure
scripts are run only if some current server or servers are being removed from service.
In general, a gconfigure script assigns clients across all servers passed to it if possible. There
are exceptions, such as services that must run on the head node only. Nothing precludes each
gconfigure script from suggesting a more optimal allocation within its user interface. Such
behavior is not expected to be typical, however.
Most services can build service-specific client lists within their gconfigure scripts completely
by using a provided API. Client information that comes from the database to enable this consists
of the following:
• Nodes identified in the database by the setting of node attributes (including the predefined
attributes, such as na_all)
• Service-specific client selection flags (such as sa_no_client_on_server)
You can use node attributes (such as na_all) to include or exclude nodes, and you can use
service attributes (such as sa_no_client_on_server) to refine the list with particular patterns.
There is a small set of convenience function APIs to return per-service client lists. These sources
of information (database, node attributes, service attributes) are sufficient in almost all cases to
build client lists.
66 Managing and Customizing System Services