Back to All ScenariosPASSEDqueue / fd_exhaustion NATS 2.10 File Descriptor Limit Reached on RHEL 9
NATS 2.10 has exhausted its file descriptor limit. Cannot accept new connections or open new files. Service functionality severely degraded.
Pattern
CONNECTION_REFUSED
| Metric | Expected | Actual | Result |
|---|
| Pattern Recognition | CONNECTION_REFUSED | CONNECTION_REFUSED | |
| Severity Assessment | HIGH | CRITICAL | |
| Incident Correlation | N/A | None | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Auto-Heal — Corax resolves autonomously | |
Scenario Conditions
RHEL 9. NATS 2.10 at 6737/6737 file descriptors. Connection leak detected. ulimit -n set to 6737 (default, not tuned for production).
Injected Error Messages (1)
NATS 2.10 on RHEL 9 — 6737/6737 FDs used, 'Too many open files', connection refused on new requests, nats-server leaking file descriptors at 17/min
Neural Engine Root Cause Analysis
Connection refused — service is likely crashed or not listening on the expected port.
Remediation Plan
Restart the target service. If recurring, check for memory leaks or crash loops.
Improvements Applied
- Severity: CRITICAL (expected HIGH)
Tested: 2026-04-02Monitors: 1 | Incidents: 1Test ID: cmnhnpyo904lblig7qw2nx79z