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PASSEDcache / fd_exhaustion
Varnish 7.5 File Descriptor Limit Reached on RHEL 9
Varnish 7.5 has exhausted its file descriptor limit. Cannot accept new connections or open new files. Service functionality severely degraded.
Pattern
CONNECTION_REFUSED
Severity
CRITICAL
Confidence
68%
Remediation
Auto-Heal
Test Results
| 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. Varnish 7.5 at 25650/25653 file descriptors. Connection leak detected. ulimit -n set to 25653 (default, not tuned for production).
Injected Error Messages (1)
Varnish 7.5 on RHEL 9 — 25650/25653 FDs used, 'Too many open files', connection refused on new requests, varnishd leaking file descriptors at 44/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: cmnhnpzzh04r7lig71ytgur85