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404
Page Not Found
The requested page could not be found. The URL may be incorrect, the route may have been removed, or the backend service may require configuration changes.
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Server & Backend Monitoring
Required server checks, backend health and error monitoring
ATTENTION REQUIRED
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WEB SERVER
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ONLINE
HTTP service responding
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APPLICATION
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CHECK
Verify application routes
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API
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CHECK
Check upstream API services
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DATABASE
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VERIFY
Check connection and queries
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Server Issues to Check
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HTTP 404 / Routing
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Verify URL routing, controller mapping, rewrite rules,
reverse proxy configuration and application routes.
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Backend Application Errors
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Check application exceptions, failed controllers,
middleware errors, dependency failures and recent deployments.
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API / Upstream Services
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Check API availability, timeout errors, HTTP 500/502/503 responses,
authentication failures and upstream connection problems.
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Database Connectivity
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Check database availability, connection pool,
failed queries, slow queries, locks and migration status.
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CPU / Memory / Disk
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Monitor CPU utilization, RAM consumption,
disk capacity, inode usage and process limits.
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SSL / HTTPS
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Verify certificate expiration, TLS configuration,
HTTPS redirects and certificate-chain errors.
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DNS / Domain
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Verify DNS records, domain resolution,
nameservers and load-balancer target configuration.
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Queue / Worker Services
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Check background workers, message queues,
failed jobs, retry queues and worker process status.
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Cron / Scheduled Jobs
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Verify scheduled tasks, cron execution,
failed jobs and last successful execution time.
Required Backend Monitors
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Error Rate
Monitor HTTP 4xx and 5xx responses.
Response Time
Monitor API and page latency.
Application Logs
Monitor errors, warnings and exceptions.
Server Logs
Monitor web server access and error logs.
Database
Monitor availability, slow queries and failures.
Disk Space
Alert before storage becomes unavailable.
SSL Certificate
Monitor certificate expiration.
Backup Status
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Verify backup completion and recovery readiness.
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Backend Log Monitoring
MONITOR REQUIRED ```[SERVER MONITOR] HTTP Errors 400 Bad Request 401 Unauthorized 403 Forbidden 404 Not Found 408 Request Timeout 429 Too Many Requests 500 Internal Server Error 502 Bad Gateway 503 Service Unavailable 504 Gateway Timeout BACKEND [ ] Application exceptions [ ] Controller failures [ ] Middleware failures [ ] Authentication failures [ ] Authorization failures [ ] API timeout errors [ ] External service failures DATABASE [ ] Connection failures [ ] Connection pool exhaustion [ ] Query failures [ ] Slow queries [ ] Database timeout [ ] Migration failures SERVER [ ] CPU utilization [ ] Memory utilization [ ] Disk utilization [ ] Disk inode usage [ ] Process availability [ ] Network connectivity INFRASTRUCTURE [ ] DNS [ ] SSL/TLS [ ] Reverse proxy [ ] Load balancer [ ] Cache [ ] Queue workers [ ] Cron jobs [ ] Backup jobs LOG SOURCES [ ] Application logs [ ] Web server access logs [ ] Web server error logs [ ] API logs [ ] Database logs [ ] System logs ACTION 1. Check latest application errors. 2. Check web-server error logs. 3. Verify route/controller configuration. 4. Verify API and upstream services. 5. Verify database connectivity. 6. Check CPU/RAM/disk metrics. 7. Check DNS and SSL configuration. 8. Review recent deployment/configuration changes. 9. Verify queue workers and scheduled jobs. 10. Confirm monitoring alerts are working.