Netgear XCM8806 Chassis User Manual - Page 65

NETGEAR 8800 User Manual Node Election Node election is based on leader election between the MSMs/MMs installed in the chassis. By default, the MSM/MM installed in slot A has primary status. Each node uses health information about itself together with a user configured priority value to compute its node role election priority. Nodes exchange their node role election priorities. During the node election process, the node with the highest node role election priority becomes the master or primary node, and the node with the second highest node role election priority becomes the backup node. All other nodes (if any) remain in STANDBY state. The primary node runs the switch management functions, and the backup node is fully prepared to become the primary node if the primary fails. Standby nodes configured to be master-capable elect a new backup node from among themselves after a failover has occurred. Determining the Primary Node The following parameters determine the primary node: • Node state-The node state must be STANDBY to participate in leader election and be selected as primary. If the node is in the INIT, DOWN, or FAIL states, it cannot participate in leader election. For more information about the node states, see Viewing Node Status on page 68. • Configuration priority-This is a user assigned priority. The configured priority is compared only after the node meets the minimum thresholds in each category for it to be healthy. Required processes and devices must not fail. • Software health-This represents the percent of processes available. • Health of secondary hardware components-This represents the health of the switch components, such as power supplies, fans, and so forth. • Slot ID-The MSM/MM slot where the node is installed (MSM-A or MSM-B). Configuring the Node Priority on a Modular Switch To configure the priority of an MSM/MM node, use the following command: configure node slot priority If you do not configure any priorities, MSM-A has a higher priority than MSM-B. For the slot_id parameter, enter A for the MSM/MM installed in slot A or B for the MSM/MM installed in slot B. By default, the priority is 0 and the node priority range is 1 through 100. The higher the value, the higher the priority. Relinquishing Primary Status Before relinquishing primary status and initiating failover, review the section Synchronizing Nodes on Modular Switches on page 825 to confirm that your platform and both installed MSMs/MMs or master-capable nodes are running software that supports the synchronize command. Chapter 3. Managing the Switch | 65