An LDAP external load balancer sits between clients and multiple LDAP servers. It distributes requests evenly, avoiding overload on any single node. This guarantees zero downtime when one server fails. Proper configuration can also improve authentication speed and reduce latency across your stack.
Core setup involves selecting a protocol-aware load balancer that supports LDAP. Most engineers choose TCP-based balancing to preserve LDAP connection states. Round-robin works for uniform workloads, but weighted balancing is better for heterogeneous LDAP nodes with varying capacities. Session persistence, sometimes called “stickiness,” can be vital when applications rely on continuous binding to the same LDAP node.
Security must be built in. Terminate TLS at the load balancer or pass it through, depending on your compliance requirements. Ensure the load balancer supports LDAPS (LDAP over SSL) and can handle authentication traffic without modifying credentials or schema.