Introduction
The Crusoe Layer 4 External Load Balancer (ELB) distributes TCP and UDP traffic across backend VMs in your VPC using transport-layer connection routing — no HTTP parsing, no session affinity based on application state, just raw connection distribution across your registered backends.
Because it operates at L4, the metrics that matter are bandwidth (Gbps) and connections per second — not requests per second, which is an application-layer concept. This FAQ covers the ELB's aggregate bandwidth ceiling, why a single backend node won't see the full 100 Gbps, and how to scale when your workload needs more capacity.
Question 1: What is the aggregate bandwidth limit for the Crusoe ELB?
The current aggregate ingress/egress limit is 100 Gbps.
Question 2: Why is my throughput lower than 100 Gbps on a single backend node?
Throughput is bounded by the weakest link between the ELB fabric and your backend nodes. While the ELB supports 100 Gbps in aggregate, each VM has its own VPC network limit — and that per-VM ceiling is what constrains you in practice. For example:
- An L40S-48GB.1x instance is limited to 17.5 Gbps.
- CPU VM limits vary by core count — see the VPC network limits by instance type for the full table.
Your effective throughput per node is capped at that VM's VPC limit regardless of how much headroom the ELB has.
Question 3: How do I increase total throughput for my application?
Scale horizontally. Per-VM limits are fixed, so the only way to use more of the ELB's 100 Gbps aggregate capacity is to distribute your workload across more backend nodes or pods. Each additional node contributes its full VPC bandwidth allowance to your aggregate.
Question 4: Does Crusoe provide limits for Requests per Second (RPS)?
No — the Crusoe ELB operates at Layer 4 (TCP/UDP), so Crusoe defines limits in terms of L4 connections per second, not RPS. Layer 7 metrics like RPS depend entirely on your application stack, your internal L7 load balancer (NGINX, Envoy, etc.), and how your application manages its connection pool. If you need RPS visibility, instrument your L7 layer directly.