Select a load balancing strategy

Northflank routes external traffic to your instances using scalable, secure, and highly performant load balancers.

By default, traffic will be distributed using the least-connection strategy. You can select the load-balancing strategy for a combined or deployment service in the networking section when creating it, or change it on the networking page of an existing service. Changes will take effect immediately and do not require redeployment.

If an instance is replaced then requests will be routed to a new instance using the same strategy.

Least-connection selects the pod with the least current open connections. This approach helps ensure even distribution of traffic across your instances, especially when requests can vary in duration and resource usage.

Consistent hashing can be used to create "sticky sessions", consistent connections between users and a specific instance.

You can choose different hash modes depending on your requirements:

Client IP address mode will use the IP address of the request to route requests to the same instances.

Custom header allows you to set the HTTP header to use, for example X-Sticky-Session. The value of this header will be hashed to consistently route to the same instance. This also allows for multiple different users to be routed to the same instance.

Round-robin balances requests by routing each request to the next instance in turn. This strategy is best if requests are fairly uniform in resource usage.

For example, with 2 instances: request 1 is routed to instance 1, request 2 is routed to instance 2, and request 3 is routed to instance 1.