# Elastic Load Balancer with only one EC2 instance Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/elastic-load-balancer-with-only-one-ec2-instance An ELB with only one registered EC2 instance does not achieve its core purpose-distributing traffic across multiple backends. By: Mike Rosenberg Updated: 2026-09-28 [Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) # Elastic Load Balancer with Only One EC2 Instance The short version An ELB with only one registered EC2 instance does not achieve its core purpose-distributing traffic across multiple backends. [Mike Rosenberg](https://www.linkedin.com/in/mike-rosenberg-48171a5/) Senior Director Of Engineering @ Nubank AWS service [AWS ELB](https://www.pointfive.co/efficiency-hub/cloud-services/aws-elb) Category [Networking](https://www.pointfive.co/efficiency-hub/service-category/networking) Reference CER-0187 Type Inefficient Architecture ## Explanation Why the waste happens and who it affects. In this configuration, the ELB adds complexity and cost without improving availability, scalability, or fault tolerance. This setup is often the result of premature scaling design or misunderstood architecture patterns. If there's no plan to horizontally scale the application, the ELB can often be removed entirely without user impact. ## Billing model The pricing dimensions that drive this cost. All ELB types are billed for each hour or partial hour the load balancer runs. Application, Network, and Gateway Load Balancers add a capacity-unit charge (LCU, NLCU, or GLCU) based on dimensions such as new and active connections and bytes processed, while Classic Load Balancers add a per-GB data processing charge. The hourly charge applies regardless of the number of targets or the actual volume of traffic being handled. Running an ELB with only a single EC2 instance incurs fixed costs without delivering the intended benefits of load distribution or redundancy. ## How to detect 4 checks to find it in your estate. - Identify load balancers with only one healthy or active EC2 instance registered - Check ELB metadata and target group configurations to validate instance count - Review deployment patterns to determine whether the architecture expects scaling but hasn't implemented it - Assess whether the ELB is used for static routing or simply passing traffic to a single backend ## How to fix 3 ways to remove the waste. - If no scaling is planned or needed, first confirm the load balancer is not providing TLS termination with ACM certificates, AWS WAF, user authentication, or health-check based replacement through an Auto Scaling group; only then remove the ELB and route traffic directly to the EC2 instance using an Elastic IP or DNS entry - If future scaling is expected, consider retaining the ELB but update documentation and monitoring to ensure it doesn't remain in this state long-term - Document architectural decisions around ELB usage to prevent future misconfigurations ## Documentation Vendor references for pricing and configuration. [Elastic Load Balancing Pricing](https://aws.amazon.com/elasticloadbalancing/pricing/) ## Related inefficiencies [Browse the library](https://www.pointfive.co/efficiency-hub) - AWS ELB CER-0359 ### [Unconsolidated Application Load Balancers per Service](https://www.pointfive.co/efficiency-hub/inefficiencies/unconsolidated-application-load-balancers-per-service) A single Application Load Balancer can route traffic for many applications using listener rules on host names and URL paths, forwarding each to its own target group. In practice many organizations give every microservice, environment or... Networking - AWS ELB CER-0059 ### [Inactive Classic Load Balancer (CLB)](https://www.pointfive.co/efficiency-hub/inefficiencies/inactive-classic-load-balancer-clb) Classic Load Balancers that no longer serve active workloads will persist if they are not properly decommissioned. This often happens after application migrations, architecture changes, or testing activities. Even if no connections or... Networking - AWS ELB CER-0006 ### [Inactive Network Load Balancer (NLB)](https://www.pointfive.co/efficiency-hub/inefficiencies/inactive-network-load-balancer-nlb) Network Load Balancers that are no longer needed often persist after architecture changes, service decommissioning, or migration projects. When no active TCP connections or traffic flow through the NLB, it still generates hourly... Networking --- Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.