# Classic Load Balancer

> Classic Load Balancers bill an hourly fee plus a per-GB charge on data processed, at worse unit economics than the ALB and NLB generations that replaced them. ZopNight inventories every CLB on its 6-hour discovery cycle, attributes each one's cost from Cost Explorer or CUR 2.0, and flags idle and migration candidates.

Source: https://zop.dev/integrations/aws/clb

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The Classic Load Balancer is AWS's legacy layer 4/7 load balancer, billed per hour plus data processed. Classic Load Balancers cost more per unit of work than ALB or NLB and signal aging infrastructure worth migrating.

## Two meters, both legacy-priced

A CLB charges for every hour it exists and again for every GB it processes. Neither meter cares whether requests arrive. The newer generations meter capacity differently: ALB and NLB charge in LCU and NLCU units that scale with actual connections, new-connection rate, and bandwidth, which usually works out cheaper for the same workload. A CLB therefore carries two costs at once: the hourly fee it bills while idle, and the premium it bills over what an equivalent ALB or NLB would charge while busy.

## How ZopNight treats a Classic Load Balancer

Every CLB turns up on the 6-hour discovery sweep, and its spend is pulled per resource from Cost Explorer or CUR 2.0. ZopNight runs two kinds of recommendation against it: idle detection, for balancers whose request counts have gone flat, and migration guidance, because a healthy CLB is still a candidate for replacement with an ALB or NLB on better pricing. There is no stop verb for any load balancer generation, so nothing here is schedulable; the levers are delete and migrate.

## The forgotten front door problem

CLBs almost never appear in new architectures, which is exactly why they leak money. The common patterns: a balancer fronting an application that was decommissioned, left behind because nobody was sure what still resolved to it; an old blue side of a blue-green setup that never got torn down; and long-lived staging stacks created years ago from templates that predate ALB. Each one bills its hourly fee around the clock.

## Locating Classic Load Balancers today

In the EC2 console, open Load Balancers and filter the type column for classic entries; the AWS CLI equivalent is the standalone elb API rather than elbv2. Zero healthy targets or an empty request metric over a few weeks makes the delete-versus-migrate decision straightforward.