HP XC System Software Installation Guide Version 3.2

You can define multiple roles on any node. The head node, in particular, can have all of these
roles if you are setting up a small cluster.
If you need more information about services and node roles, see the HP XC System Software
Administration Guide.
F.3.1 Availability Role
The availability role is automatically assigned to all nodes that are members of availability
sets. You cannot assign this role to any node.
The configuration and management database names of the services provided by the
availability role are avail and translate.
The avail entry points make configuration specific changes for availability including configuring
the node to run the configured availability tools. The translate entry point calls the availability
tool scripts, which traverse the configuration and management database to obtain information
about services configured for availability. The availability tool scripts create the configuration
files necessary to enable the availability tool on the nodes on which it was configured.
F.3.2 Avail_node_management Role
Assign the avail_node_management role to fail over services on the head node that are usually
supplied by the node_management role. In this release, the database server service is the only
service supplied by the avail_node_management role.
Because you cannot assign the node_management role to any other node except the head node,
the avail_node_management role was developed to accomplish that task.
Never assign the avail_node_management role to the head node. Assign the
avail_node_management role only to the second node in an availability set to fail over the
database server (dbserver) service.
F.3.3 Common Role
The common role is automatically assigned to all nodes, and it cannot be removed. This role runs
services that must be present on every node.
The configuration and management database names of the services provided by this role are as
follows:
• Node data collection with the collectl utility (collectl)
• Hardware information gathering (gather_data)
• Environmental monitoring for the HP ProLiant DL585 server (hpasm)
• HPTC file system client (hptc_cluster_fs_client)
• IP firewall (iptables)
• IP firewall for IPv6 (ip6tables)
• Linux kernel crash dump (lkcd)
• Network adapter setup (network)
• Nagios remote plug-in execution agent (nrpe)
• Parallel distributed shell (pdsh)
• SLURM launch (munge)
• Disk monitoring on the HP Integrity rx1620 (smartd)
These services provide functionality that is required on all nodes and are fundamental to the
proper functioning of the cluster.
F.3.4 Compute Role
Jobs are distributed to and run on nodes with the compute role. This role provides the services
required for the node to be an allocated resource of the SLURM central control service (slurmcd).
On systems with fewer than 63 total nodes, this role is assigned to all nodes; on large-scale systems
with more than 64 nodes, this role is assigned exclusively to nodes with no other roles assigned.
F.3 Role Definitions 211