Sun HPC ClusterTools 3.0 Administrator's Guide: With CRE

Customizing Cluster-Level Attributes

This section describes various Cluster-level attributes that you may want to modify. Table 6-4 lists the attributes that can be changed in the Cluster context.

Table 6-4 Cluster-Level Attributes


Attribute	Kind	Description
`default_interactive_partition`	Value	Specifies the default partition.
`logfile`	Value	Specifies an optional output file for logging CRE daemon error messages.
`administrator`	Value	Specifies an email address for the system administrator(s).
`lock_max_age`	Value	Specifies the maximum amount of time a lock can remain set (the value is in seconds)

`default_interactive_partition`

This attribute specifies the default partition for running MPI jobs. Its value is used by the command mprun, which is described in the Sun HPC Cluster Runtime Environment 1.0 User's Guide.

For example, to make a partition named part0 the default partition, enter the following in the Cluster context:

[node0]:: set default_interactive_partition=part0

When a user executes a program via mprun, the CRE decides where to run the program, based on the following criteria:

Check for the command-line -p option. If a partition is specified, execute the program in that partition. If the specified partition is invalid, the command will fail.
Check to see if the MPRUN_FLAGS environment variable specifies a default partition. If so, execute the program in that partition. If the specified partition is invalid, the command will fail.
Check to see if the SUNHPC_PART environment variable has a value set. If it specifies a default partition, execute the program in that partition. If the specified partition is invalid, then check to see if the user is logged into any partition. If so, execute the program in that partition.
Check to see if the user is logged into a partition. Execute the program in that partition.
If none of these checks yield a partition name, check for the existence of the default_interactive_partition attribute. If it specifies a partition, execute the program in that partition.

The SUNHPC_PART environment variable is described in "CRE Environment Variables". The MPRUN_FLAGS environment variable is described in the Sun MPI 4.0 User's Guide: With CRE.

`logfile`

The logfile attribute allows you to log CRE messages in a file separate from all other system messages. For example, if you enter

[node0]:: set logfile=/home/wmitty/cre-messages

CRE will output its messages to the file /home/wmitty/cre-messages. If logfile is not set, CRE messages will be passed to syslog, which will store them with other system messages in /var/adm/messages.

Note -

A full path name must be specified when setting the logfile attribute.

`administrator`

Set the administrator attribute to specify the email address of the system administrator. For example:

[node0]:: set administrator="root@example.com"

Note the use of double quotes.

`lock_max_age`

The CRE uses locks for internal purposes. The lock_max_age attribute specifies the length of time that the CRE will wait before removing a lock. For example, to set the maximum lock interval to two minutes, enter the following:

[node0]:: set lock_max_age="2 minutes"

The default is 10 minutes.