The Correction Layer is a mechanism that handles asymmetric connections in systems with several cluster members. It allows traffic flow to be handled by a single cluster member, even if the flow is asymmetric1
The Correction Layer works as follows:
•When a packet arrives at a cluster member, it checks if it is the owner of the connection. If yes, it processes the packet normally. If not, it checks the Correction table to find the owner of the connection.
•If the owner is found in the Correction table, the packet is forwarded to the owner with a Correction Layer header. The owner then processes the packet and removes the Correction Layer header before sending it to the destination.
•If the owner is not found in the Correction table, the packet is forwarded to the Maestro Orchestrator (MHO) with a Correction Layer header. The MHO then checks its own Correction table to find the owner of the connection. If the owner is found, the MHO forwards the packet to the owner with a Correction Layer header. If the owner is not found, the MHO drops the packet and sends an ICMP error message to the source.
•The Correction tables are updated by the MHO whenever a new connection is established or an existing connection is terminated. The MHO sends Correction Layer messages to all cluster members to inform them about the owner of each connection2
