Flannel — Benchmarks
Scope
Performance characteristics, scaling limits, and resource consumption for Flannel.
| Backend |
Throughput (10GbE) |
Latency Overhead |
Encryption |
| VXLAN |
8-9 Gbps |
+80-100us |
No |
| host-gw |
9.5+ Gbps |
+10-20us |
No |
| WireGuard |
7-8 Gbps |
+100-200us |
Yes |
| UDP (deprecated) |
5-6 Gbps |
+200-500us |
No |
Resource Usage
| Metric |
Per Node |
Notes |
| CPU (idle) |
< 10m |
Minimal overhead |
| CPU (active) |
50-200m |
Under heavy traffic |
| Memory |
30-50Mi |
Lightweight |
Scaling Limits
| Dimension |
Limit |
Notes |
| Nodes per cluster |
5,000+ |
Same as K8s limit |
| Pods per node |
110 |
K8s default, not Flannel limit |
| Subnet size |
/24 per node (default) |
Configurable via SubnetLen |