Cloud Architecture with State-Saving Middlebox Scaling

摘要

An enterprise computer system efficiently adjusts the number of middleboxes associated with the the enterprise, for example, with changes in demand, by transferring not only flows of instructions but also middlebox states associated with those flows. Loss-less transfer preventing the loss of packets and its state, and order-preserving transfer preserving packet ordering may be provided by a two-step transfer process in which packets are buffered during the transfer and are marked to be processed by a receiving middlebox before processing by that middlebox of ongoing packets for the given flow.

主权项

1. A computing system comprising a plurality of computers interconnected with switches and executing a program stored in non-transitory medium to implement enterprises using multiple machines intercommunicating packets, the computing system comprising:
(1) a central controller dynamically allocating machines to a given enterprise; (2) at least first and second middleboxes receiving a packet flow and collecting state information with respect to the flow, the state information used for processing the packets received by the middlebox, the first and second middleboxes being instances of a common machine object; and wherein the computing system further executes the program to: (i) receive instructions to change a number of middleboxes and identify a given flow of packets to he received by the second middlebox; (ii) in response to the instructions, transfer state data of the first middlebox related to the given flow to the second middlebox; and (iii) in response to the instructions, control the switches to transfer ongoing packets of the given flow to the second middlebox;. wherein the computing system further: begins buffering packets of the given flow of packets to the first middlebox before (ii); and transfers the buffered packets of the given flow to the second middlebox after step (ii).