Patent attributes
One aspect of the present technology can provide a system for facilitating in-service software upgrade (ISSU) for a switch in a virtual switching stack. During operation, the system can initiate ISSU that facilitate uninterrupted traffic flow. The system can upgrade a first set of daemons of the switch that manage operations of the switch. The system can also upgrade a database stored on the switch. The database can store operational information of the switch. The system can further upgrade a second set of daemons of the switch that configure forwarding information on the forwarding hardware of the switch and facilitate data-plane operations for the switch. The forwarding information configured on the forwarding hardware can remain unchanged during the upgrade. The system can configure the upgraded second set of daemons to obtain control-plane information from a standby switch of a conductor switch of the virtual switching stack.