Implementing History-Based Connection-Server Affinity On A Network Load Balancer

A network load balancer comprising:

• a processor configured to:
• receive a network packet destined for a service, the service being associated with a plurality of servers, the network packet being part of a network connection between a client device and one of the plurality of servers;
• compute, using a portion of the network packet, a bucket identifier of a bucket for the network connection;
• identify a first server in the plurality of servers that is currently mapped to the bucket identifier in a hash table of the network load balancer, the hash table being generated by populating the hash table with active servers and inactive servers, and by remapping the inactive servers to the active servers;
• send the network packet to the first server;
• receive the network packet back from the first server;
• and
• in response to receiving the network packet back from the first server:
• determine a second server in the plurality of servers that was previously mapped to the bucket identifier in the hash table, the determining being based on history information maintained on the network load balancer;
• and
• send the network packet to the second server.

A non-transitory computer readable storage medium have stored thereon program code executable by a network load balancer, the program code comprising:

• code that causes the network load balancer to receive a network packet destined for a service, the service being associated with a plurality of servers, the network packet being part of a network connection between a client device and one of the plurality of servers;
• code that causes the network load balancer to compute, using a portion of the network packet, a bucket identifier of a bucket for the network connection;
• code that causes the network load balancer to identify a first server in the plurality of servers that is currently mapped to the bucket identifier in a hash table of the network load balancer, the hash table being generated by populating the hash table with active servers and inactive servers, and by remapping the inactive servers to the active servers;
• code that causes the network load balancer to send the network packet to the first server;
• code that causes the network load balancer to receive the network packet back from the first server;
• and
• in response to receiving the network packet back from the first server:
• code that causes the network load balancer to determine a second server in the plurality of servers that was previously mapped to the bucket identifier in the hash table, the determining being based on history information maintained on the network load balancer;
• and
• code that causes the network load balancer to send the network packet to the second server.