Bright:Concepts
Devices
A Device in Bright is and Physical piece of hardware in the cluster including:
- Head Nodes
- Compute Nodes
- Virtual SMP Nodes - because it is made up of compute nodes
- GPU Unit
- Ethernet Switch
- Infiniband Switch
- Myrinet Switch
- Power Distrubution Unit
- Rack Sensor Kit
- Generic Devices
Each of these devices have their own properties including rack location, hostnames, ports, etc. These can be set or changed through Bright.
The devices will also have one of three states associated with it: Up, Down or Closed
Software Images
A software image defines the local files system for a node. The image is stored on the head node and used at installation of the node. The default image is based on the OS used on the head node.
While other distros can be used, it should be pointed out that this can make cluster management more difficult. Different versions of the same distro should not cause the same problems eg Centos 6.3 and 6.4.
Once a node has been installed using the image, it is poosble to re sync the node back to the image with out rebooting. It is also possible to prevent the node resyncing.
Node Categories
A node category combines a software image with a number of other settings including disk layout,network interfaces and access rights. This allow two nodes to use the same image, but have different configurations.
Node Groups
A node group allows a set up nodes to be control together. This allows for example the image to be changed over several nodes, rather than changing them individually.
Roles
Each node can be assigned specific roles. Assigning a role to a nodes, gives the node the functionality associated with that role. As an example a node given the provisioning role, would allow the node to respond to installation requests.