ERROR: Database connection timeout after 30 seconds
WARNING: Memory usage exceeded 80% threshold (current: 85%)
CRITICAL: Disk space below 5% on /var/log partition
INFO: User session expired, redirecting to login page
DEBUG: Cache miss for key user_profile_12345
FATAL: Unable to start application server on port 8080
ERROR: Payment processing failed - card declined
WARNING: Rate limit exceeded for API key abc123
CRITICAL: Security breach detected - multiple failed login attempts
INFO: Scheduled maintenance window starting in 10 minutes
ERROR: Failed to send notification email to user@example.com
WARNING: SSL certificate expires in 7 days
DEBUG: SQL query execution time: 2.5 seconds (slow query)
FATAL: Out of memory - cannot allocate additional heap space
ERROR: External API call failed - timeout to payments.example.com
