Patent ID: 8209403

Claim:
A method operated in conjunction with one or more processors to update network devices, comprising: executing one or more control modules operating on one or more processors that are configured to perform actions, including: selecting a first member within a plurality of members in a first cluster; bifurcating the first cluster, wherein the bifurcation comprises: creating a second cluster, wherein the second cluster includes the selected first member; activating the first member within the second cluster, wherein the first member is activated with a defined configuration upgrade; and iteratively upgrading each other member in the first cluster by: draining at least one existing connection managed by a member to be joined in the second cluster, wherein draining at least one existing connection further comprises at least one of changing an HTTP connection header value in a request or response to indicate reducing or otherwise modifying a keep-alive time period of an associated connection, or performing any other protocol-specific action to shutdown at least one existing network connection by reducing a keep-alive time period; removing at least one other member from the first cluster; upgrading the at least one other member with the defined upgrade; joining the at least one other member as a member to the second cluster; and determining when a defined failover criteria is satisfied, and when the defined failover criteria is satisfied, failing over connectivity from the first cluster to the second cluster such that the second cluster becomes an active cluster for managing connections and continuing to iteratively upgrade remaining members in the first cluster to join the second cluster.