What is the purpose of the Sticky Decision Function (SDF) in an Active-Active cluster?

The Sticky Decision Function (SDF) plays a crucial role in an Active-Active cluster by ensuring that traffic is efficiently distributed among the members of the cluster while also maintaining session persistence. This means that once a connection is established with a specific cluster member, all packets for that session are sent to the same member, supporting session continuity and data integrity.

SDF is particularly relevant in scenarios involving asymmetric routing, where traffic flows through different paths which can lead to challenges in maintaining statefulness in connections. By utilizing SDF, the cluster can handle sessions consistently and reduce the likelihood of interrupted connections due to packet misrouting. This is essential for applications that require stable and reliable connections, as it ensures that return traffic is directed back to the right member of the cluster.

In contrast, the other options do not align with the core functionality of SDF. While symmetric routing and failovers are important aspects of network design, they do not specifically relate to the management of traffic sessions as handled by SDF in an Active-Active configuration. Anti-Spoofing relates to security measures in preventing unauthorized addresses from entering the network, which is a distinct area of focus and does not pertain to the traffic distribution mechanisms of the SDF.