Most developers can write brilliant application code but freeze when faced with a 502 Bad Gateway error. The reality is that understanding basic system administration makes you a more versatile and effective programmer. Here's what you should know:

# Process management
ps aux | grep python  # Find running Python processes
kill -9 [PID]        # Force kill unresponsive process

# Network diagnostics
netstat -tulnp       # List all listening ports
traceroute google.com # Network path analysis

# Disk space analysis
df -h                # Show disk usage
du -sh * | sort -hr  # Find space hogs

Developers often debug using IDE tools but ignore server logs. For web applications:

# Nginx/Apache error logs
tail -f /var/log/nginx/error.log  # Real-time log monitoring
grep "500" /var/log/apache2/error.log # Filter HTTP 500 errors

# Application log best practice (Python example)
import logging
logging.basicConfig(
    filename='/var/log/myapp.log',
    level=logging.ERROR,
    format='%(asctime)s - %(levelname)s - %(message)s'
)

When you need to access databases or internal services:

ssh -L 3306:localhost:3306 user@production-server  # MySQL tunnel
ssh -D 8080 user@staging-server  # SOCKS proxy for web debugging

Every developer should implement these in their applications:

# Firewall basics (UFW example)
sudo ufw allow 22/tcp   # SSH
sudo ufw allow 80/tcp   # HTTP
sudo ufw enable

# SSH security in /etc/ssh/sshd_config
PasswordAuthentication no
PermitRootLogin no
AllowUsers developer1 developer2

Basic shell scripting knowledge saves hours:

#!/bin/bash
# Simple deployment script
rsync -avz --delete ./dist/ user@server:/var/www/html/
ssh user@server "systemctl restart nginx"

• strace -p [PID] - Trace system calls
• lsof -i :8080 - Find processes using port 8080
• journalctl -xe - Systemd service debugging

The line between developer and sysadmin is blurring in modern DevOps environments. Investing time in these skills will make you more self-sufficient and valuable.

As programmers, we often focus on writing clean code while taking infrastructure for granted - until we face production issues without sysadmin support. Here's what I've learned through painful experience about maintaining systems while shipping code.

# Process management
ps aux | grep python
kill -9 [PID]
top/htop

# Network diagnostics
netstat -tulnp
ss -plant
traceroute google.com
ping -c 4 8.8.8.8

# Disk space management
df -h
du -sh *
lsof | grep deleted  # Find processes holding deleted files

Every developer should understand:

# Basic cron syntax
* * * * * /path/to/command arg1 arg2

# Common patterns:
0 */6 * * *  # Every 6 hours
@reboot       # Run on startup
30 3 * * 1-5  # 3:30 AM weekdays

# Log rotation example in /etc/logrotate.d/
/var/log/myapp.log {
    daily
    missingok
    rotate 7
    compress
    delaycompress
    notifempty
    create 640 root adm
    postrotate
        /usr/bin/systemctl reload myapp.service > /dev/null
    endscript
}

When you're your own sysadmin:

# ~/.ssh/config example
Host myserver
    HostName 192.168.1.100
    User deploy
    Port 2222
    IdentityFile ~/.ssh/deploy_key
    ServerAliveInterval 60

# Key generation (Ed25519 recommended)
ssh-keygen -t ed25519 -a 100 -f ~/.ssh/production_key

# Basic hardening in /etc/ssh/sshd_config
PermitRootLogin no
PasswordAuthentication no
MaxAuthTries 3
ClientAliveInterval 300

Essential commands to memorize:

# When things break:
journalctl -xe -u nginx --no-pager  # Service logs
dmesg | tail -20                    # Kernel messages
strace -p [PID]                     # Process system calls
nc -zv example.com 443              # Port testing

# Filesystem repair:
fsck /dev/sda1
mount -o remount,rw /  # Remount read-write if frozen

Quick diagnostics every dev should know:

# Memory usage
free -m
vmstat 1

# IO bottlenecks
iostat -x 1
iotop

# Network throughput
iftop -nP
nethogs

# Python-specific example
import resource
soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))

Avoid these common pitfalls:

# Simple encrypted backup with rsync
rsync -avz -e "ssh -p 2222" /critical/data user@backup:/storage \
  --delete --backup --backup-dir=$(date +\%Y-\%m-\%d)

# MySQL backup example
mysqldump -u root -p --single-transaction \
  --routines --triggers --all-databases \
  | gpg -c --batch --passphrase mysecret \
  > backup_$(date +\%F).sql.gpg

# Test restores monthly!

Recognize your limits - some scenarios require experts:

• RAID array failures
• Complex network partitioning issues
• Kernel panics without clear logs
• Security breaches requiring forensics