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PASSEDcache / memory_exhaustion
Varnish 7.5 Memory Leak — Heap Growing Unbounded on RHEL 9
Varnish 7.5 has a memory leak causing heap/RSS to grow continuously. Memory usage at 75% and climbing. Performance severely degraded.
Pattern
MEMORY_EXHAUSTION
Severity
CRITICAL
Confidence
72%
Remediation
Auto-Heal
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | MEMORY_EXHAUSTION | MEMORY_EXHAUSTION | |
| 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 RSS at 3GB (limit: 4GB). Memory growing 1MB/hour. GC/eviction not keeping up. Swap pressure increasing.
Injected Error Messages (1)
Varnish 7.5 memory leak on RHEL 9 — memory critical, RSS 3GB/4GB (75%), out of memory imminent, growing 1MB/hour, garbage collection overhead 23%
Neural Engine Root Cause Analysis
Memory exhaustion detected — the system has run out of available memory, triggering the OOM killer or forcing heavy swap usage. This causes severe performance degradation and can result in random process termination. Memory leaks in long-running applications are a common root cause, especially after deployments or configuration changes.
Remediation Plan
1. Check which process was OOM-killed using 'dmesg | grep -i oom' or journal logs.
2. Review memory usage by process with 'ps aux --sort=-%mem | head -20'.
3. Restart the affected service to reclaim leaked memory.
4. If a memory leak is suspected, enable heap profiling and analyze memory allocation patterns.
5. Consider increasing server memory or setting appropriate memory limits (cgroups/container limits).
Improvements Applied
- Severity: CRITICAL (expected HIGH)
Tested: 2026-04-02Monitors: 1 | Incidents: 1Test ID: cmnhnpljy037jlig7bbh3xk0o