Server Management

Server management principles for production operations. Learn to THINK, not memorize commands.

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1. Process Management Principles

Tool Selection

Scenario	Tool
Node.js app	PM2 (clustering, reload)
Any app	systemd (Linux native)
Containers	Docker/Podman
Orchestration	Kubernetes, Docker Swarm

Process Management Goals

Goal	What It Means
Restart on crash	Auto-recovery
Zero-downtime reload	No service interruption
Clustering	Use all CPU cores
Persistence	Survive server reboot

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2. Monitoring Principles

What to Monitor

Category	Key Metrics
Availability	Uptime, health checks
Performance	Response time, throughput
Errors	Error rate, types
Resources	CPU, memory, disk

Alert Severity Strategy

Level	Response
Critical	Immediate action
Warning	Investigate soon
Info	Review daily

Monitoring Tool Selection

Need	Options
Simple/Free	PM2 metrics, htop
Full observability	Grafana, Datadog
Error tracking	Sentry
Uptime	UptimeRobot, Pingdom

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3. Log Management Principles

Log Strategy

Log Type	Purpose
Application logs	Debug, audit
Access logs	Traffic analysis
Error logs	Issue detection

Log Principles

1. Rotate logs to prevent disk fill
2. Structured logging (JSON) for parsing
3. Appropriate levels (error/warn/info/debug)
4. No sensitive data in logs

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4. Scaling Decisions

When to Scale

Symptom	Solution
High CPU	Add instances (horizontal)
High memory	Increase RAM or fix leak
Slow response	Profile first, then scale
Traffic spikes	Auto-scaling

Scaling Strategy

Type	When to Use
Vertical	Quick fix, single instance
Horizontal	Sustainable, distributed
Auto	Variable traffic

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5. Health Check Principles

What Constitutes Healthy

Check	Meaning
HTTP 200	Service responding
Database connected	Data accessible
Dependencies OK	External services reachable
Resources OK	CPU/memory not exhausted

Health Check Implementation

• Simple: Just return 200
• Deep: Check all dependencies
• Choose based on load balancer needs

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6. Security Principles

Area	Principle
Access	SSH keys only, no passwords
Firewall	Only needed ports open
Updates	Regular security patches
Secrets	Environment vars, not files
Audit	Log access and changes

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7. Troubleshooting Priority

When something's wrong:

1. Check if running (process status)
2. Check logs (error messages)
3. Check resources (disk, memory, CPU)
4. Check network (ports, DNS)
5. Check dependencies (database, APIs)

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8. Anti-Patterns

❌ Don't	✅ Do
Run as root	Use non-root user
Ignore logs	Set up log rotation
Skip monitoring	Monitor from day one
Manual restarts	Auto-restart config
No backups	Regular backup schedule

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Remember: A well-managed server is boring. That's the goal.