📊 Monitoring & Alerting Systems

1. Tools Used

Modern IT infrastructure relies heavily on comprehensive monitoring and alerting systems to ensure uptime, performance, and security. Common tools include:

• Prometheus: Time-series data monitoring with Grafana for dashboards.
• Datadog: Full-stack observability including traces, logs, metrics, and APM.
• New Relic: Application and infrastructure performance monitoring.
• Nagios: Open-source solution for host and service monitoring.
• Zabbix: Real-time monitoring and alerting platform with visualization.

2. What’s Monitored and Why

• CPU, memory, and disk usage of servers and containers.
• Application response times and error rates.
• Availability of network endpoints (ping, HTTP checks).
• Log ingestion for error patterns or anomalies.
• Security-related metrics like failed logins and suspicious access.
• Database health including replication lag, slow queries, and size growth.

3. Alert Escalation Matrix

• Level 1: Non-critical alerts sent to on-call engineers via Slack/email.
• Level 2: Repeated or unresolved alerts escalate to team leads via SMS or call.
• Level 3: Critical system failure triggers company-wide alerts and disaster recovery protocol.
• Use tools like PagerDuty, Opsgenie, or VictorOps for incident routing.

4. SLA Thresholds

Service Level Agreements (SLAs) define the acceptable uptime and performance metrics. Monitoring must continuously evaluate:

• 99.9% uptime (maximum ~43 min downtime per month)
• Mean Time to Detect (MTTD) and Mean Time to Resolve (MTTR)
• Response time thresholds per endpoint (e.g., <500ms)
• Error rate ceilings (e.g., <1%)

5. Response Checklist

• Verify the alert is legitimate and reproducible.
• Review logs and metrics to locate root cause.
• Notify stakeholders and document ongoing status.
• Mitigate impact through rollbacks, scaling, or patches.
• Log the incident in a tracking system (e.g., Jira, ServiceNow).
• Conduct post-incident review to prevent recurrence.