| name | load-balancer-skill |
| description | Identify load-balancer-side service faults. Use when the topology includes a load balancer (nginx, HAProxy) and the LB itself shows pressure — slow VIP, command or helper timeouts on the LB, failed IP lookups, or CPU/socket spikes while backends are healthy. |
load_balancer_overload
Fingerprint (any 2 → submit)
- ICMP to the LB known IP succeeds. Use an IP from
safe_reachability or a host's resolver; do not rely on a name lookup that itself depends on the LB.
- HTTP/VIP probe from a client fails, times out, or returns an empty body.
- Shell command on the LB times out —
exec_shell hangs, infra_sweep reports exec_failed on the LB, safe_reachability IP lookup fails on the LB, or pressure_sweep times out on the LB.
Submit
is_anomaly=True
root_cause_name=["load_balancer_overload"]
faulty_devices=["<load_balancer_device_name>"]
One direct probe to confirm the pattern is enough. Do not chain extra investigations once two fingerprints match.
Not host_crash
host_crash means the container was killed/stopped/removed: no ICMP, no response of any kind, and the same-role baseline stays clean. Any partial LB response — ICMP reply, partial HTTP, localhost nginx answer — rules out host_crash.
Not web_dos_attack
Switch only if a running HTTP flood tool (ab, wrk, hping3, hey, httperf, siege, vegeta, locust) is found on an attacker host and targets the LB/VIP. Probe-traffic log entries are not flood evidence.
Not resource-contention-skill
Stay here when the LB itself is the flagged device. Route to resource-contention-skill only when the direct pressure signal is on a non-LB backend or client and the LB stays clean.