Infrastructure · Software component

Round-Robin Load Balancer

Software componentInfrastructureInfrastructurearc:RoundRobinLoadBalancer

A load balancer that assigns requests to replicas in fixed circular order, giving equal request counts regardless of request complexity or current replica load.

Responsibility. Distributes requests sequentially and evenly across replicas.

Also known as: Round robin

Variant of Load Balancer abstract

When to choose. Choose only when all requests have similar processing cost and all replicas identical capacity.

Direct neighbourhood (hover for relationship types)

Relationships

alternative to variability

Design guidance

SHOULD be reserved for workloads with uniform request processing times on identically sized replicas.

Quantitative guidance

As stated by the sources; verify before use.

Document-processing case: round robin across 5 replicas gave 25-95% CPU spread, P95 latency 45 s (SLO 30 s violated) and ~8x latency variation for identical documents (Ch4.7).

Classification

Patterns: Round-robin routing
Quality attributes: Maintainability (ISO/IEC 25010)Reliability (ISO/IEC 25010 | NIST AI RMF: valid and reliable)

Sources

Ch4.7: T. Nguyen, "Scaling Strategies," in Mastering Agentic AI Systems: Guide for the NVIDIA NCP-AAI Exam, 1st ed. 2026, ch. 4.7. ISBN: 9798244538229.