Monitoring Trifecta - CloudWatch

Basics

• "eyes and ears" of your AWS env
• the "central nervous system" of the cloud
  • colelcts signals (data), makes sense of them (analysis), and can trigger reflexes (automation) when something goes wrong
• a collections of tools

Types of Data

• Metrics: numerical data like "what is the CPU usage of my server right now?"
• Logs: text based records
• Events: changes in the AWS env that can trigger automated responses

Goals:

• Data Silos: single location to view the status of entire cloud env
• Reactive Fixing: proactive monitoring, when something happens, it reports it
• Manual Scaling: it can tell AWS to automatically add more servers to handle the load
• Hidden Errors: provides deep visibility, search through logs

Why is it needed:

• Operational Health: know something's wrong the moment it happens
• Cost Optimization: identify zombie resources
• Security & Compliance: monitoring logs, spot unusual activie, (an IP address logs 1k times in a minute, block it automatically)
• TroubleShooting (MTTR): reduces the Mean Time to Resolution. when an error occurs, you can correlate a pike in a metric (like latency) directly with a specific log entry to find the root cause instantly

Components

• Dashboards: visual graphs of your metrics
• Alarms: if CPU > 80% for 5 mins, send alert
• Logs Insights: query language to search through logs
• Synthetics: scripts that "ping" your website to check for availability and broken links

Diff between AWS Config and AWS CloudWatch?

• AWS Config monitors Compliance while CloudWatch monitors Performance
• AWS Config is best for real-time monitoring and auto-scaling, where CloudWatch is best for tracking changes over time

The "Trifecta"

• CloudWatch: tells you what is happening (high CPU)
• AWS Config: tells you what changed in the setup (someone changed the instance to a smaller one)
• CloudTrail: tells you who did it (user "Admin_Bob" made the change)