HP XC System Software Administration Guide Version 4.0

Nodes with na_disable_server.service assigned for a service are excluded from the server
list passed into the gconfig script as servers. Nodes with na_disable_client.service
assigned for a service are not returned as potential clients of that service. In general, these flags
are something the gconfig script does not need to handle explicitly.
Nothing precludes each gconfig script from offering optimal choices to you through its user
interface. The APIs provided for server and client selection and mappings make no assertions
regarding the interrelationship of the servers that are configured.
4.6.5.3 The nconfigure Scripts
An nconfigure script in the /opt/hptc/etc/nconfig.d directory modifies individual
server nodes and sets up any server-specific configuration required for a particular service. An
nconfigure script is executed only on nodes that are servers of the service.
An nconfigure script is executed inside the cluster_config utility as follows:
script_path nconfigure server
script_path nunconfigure server
The server is the node name on which the script is running. The nconfigure action is performed
only on nodes that are servers of the service. The nconfigure scripts cannot have a user interface.
The nconfigure scripts return 0 (zero) on success and return a nonzero value on failure. Any
failure causes the node to be put into single-user mode so that the error can be investigated.
The nunconfigure action is not performed automatically, but it should be available to be
performed manually.
4.6.5.4 The cconfigure Scripts
A cconfigure script in the /opt/hptc/etc/cconfig.d directory sets up client-specific
configuration required for a particular service.
The cconfigure scripts are executed inside the cluster_config utility as follows:
script_path cconfigure client server1 server2 ...
script_path cunconfigure client server1 server2 ...
The client is the node name on which the script is running. The servers are the nodes providing
this service to this client. Typically, this is a single server. The cconfigure action is performed
only on nodes that are clients of the service. The cconfigure scripts return 0 (zero) on success
and return a nonzero value on failure. Any failure causes the node to be put into single-user
mode so that the error can be investigated. The cconfigure scripts cannot have a user interface.
The cunconfigure action is not performed automatically, but it should be available to be
performed manually.
4.6.6 Understanding Global Configuration Scripts
Imagine a role containing two or more services. With the present roles interface, every node for
which this role is specified is selected as a potential server for these services. Imagine further
that 10 nodes are assigned with this role. This potentially assigns these services to these 10 nodes.
Eventually, these 10 nodes are passed as potential servers to the gconfig scripts for these
services.
This results in two or more gconfig scripts receiving the same 10 nodes on which to schedule
services. The instruction to each gconfig script is to use all of the servers it is passed, if possible.
Two or more services might not have compatible or consistent uses for the same set of 10 server
nodes passed into them. Also, each service might benefit from optimizing its service assignments
relative to the other services on the same set of nodes; however, there are no mechanisms to
achieve this.
Another possible behavior of the system that you might want is that each gconfig script could
identify that it needs only 5 of the 10 servers to satisfy optimal scale out requirements, and these
4.6 Customizing Services and Roles 69