Understanding the Director Group
Because the Director group provides management services for the QFabric system, it is important to understand the components of the cluster and how the Director group supports the needs of the greater fabric.
Director Group Components
When you build a Director group, consider the following elements and concepts.
Director device—A single management device for the QFabric system. Director devices with a hard drive provide full processing services and are used to build the Director group.
Director group—A set of Director devices. The Director group is essential to the QFabric system, which cannot operate properly without it. The Director group shares and load-balances processing tasks for the QFabric system, performs topology discovery, assigns identifiers to QFabric system components, and manages interfabric communication. The primary devices in a Director group are Director devices that contain hard drives. The Director devices run dual processes in active or standby mode for maximum redundancy.
When you add additional Director devices to the group, the Director group coordinates their activities and distributes processing loads across all available Director devices. The additional Director devices provide the Director group with additional memory and processing power. Supplementing the Director group with extra Director devices allows the group to scale efficiently and serve the needs of the entire QFabric system as it grows.
Director Group Services
The Director group is a management platform that establishes, monitors, and maintains all components in the QFabric system. It is a set of Director devices that run the Junos operating system (Junos OS) on top of a CentOS foundation. The Director group handles tasks such as QFabric system network topology discovery, Node and Interconnect device configuration and startup, and Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), and Network File System (NFS) services. The Director group also runs the software for management applications, hosts and load-balances internal processes for the QFabric system, maintains configuration and topology databases, and starts additional QFabric system processes as requested.
Another critical role provided by the Director group is the hosting of the virtual Junos Routing Engines. These Routing Engines provide services for the QFabric system to keep it operating smoothly.