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PASSEDcloud / aws_rds
RDS Connection Limit Reached
An RDS MySQL instance hit the max_connections limit. New connections rejected. Application connection pools failing to acquire connections.
Pattern
DATABASE_EVENT
Expected: DATABASE_CONNECTIONS
Severity
HIGH
Confidence
68%
Remediation
Auto-Heal
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | DATABASE_CONNECTIONS | DATABASE_EVENT | |
| Severity Assessment | HIGH | HIGH | |
| Incident Correlation | N/A | None | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Auto-Heal — Corax resolves autonomously |
Scenario Conditions
AWS RDS db.t3.medium. MySQL 8.0. max_connections=85 (t3.medium default). 85/85 connections active. Connection pool wait queue at 200+.
Injected Error Messages (1)
AWS RDS max connections reached — instance app-db at 85/85 connections (t3.medium limit), new connections refused: 'Too many connections', application pool wait queue 200+
Neural Engine Root Cause Analysis
Database infrastructure event detected — the connection pool may be exhausted preventing new connections, replication lag is growing between primary and replica, deadlocks are occurring between competing transactions, or slow queries are degrading overall database performance. Database issues cascade to affect all applications and services that depend on the database.
Remediation Plan
1. For connection pool exhaustion, check current connections with 'SHOW PROCESSLIST' or 'pg_stat_activity' and identify idle/stuck connections.
2. For replication lag, check replica I/O and SQL thread status and identify long-running transactions on the primary.
3. For deadlocks, review the deadlock graph (InnoDB: 'SHOW ENGINE INNODB STATUS', Postgres: check pg_locks) and optimize transaction ordering.
4. For slow queries, enable and review the slow query log, add missing indexes, and optimize query plans with EXPLAIN.
5. Consider scaling read replicas or implementing connection pooling (PgBouncer/ProxySQL) if connection limits are consistently hit.
Improvements Applied
- Pattern classified as DATABASE_EVENT (expected DATABASE_CONNECTIONS)
Tested: 2026-04-02Monitors: 1 | Incidents: 1Test ID: cmnhnoo5z001alig7lotuxle6