Cluster architecture for network security processing

A computing device may be joined to a cluster by discovering the device, determining whether the device is eligible to join the cluster, configuring the device, and assigning the device a cluster role. A device may be assigned to act as a cluster master, backup master, active device, standby device, or another role. The cluster master may be configured to assign tasks, such as network flow processing to the cluster devices. The cluster master and backup master may maintain global, run-time synchronization data pertaining to each of the network flows, shared resources, cluster configuration, and the like. The devices within the cluster may monitor one another. Monitoring may include transmitting status messages comprising indicators of device health to the other devices in the cluster. In the event a device satisfies failover conditions, a failover operation to replace the device with another standby device, may be performed.