السجلات والمقاييس والتتبّعات

في هذا الدرس

know which signal answers which question.

الموضوعات المخطط لها

• Metrics: numbers over time, cheap, good for "is something wrong and how much?".
• Logs: events with detail, good for "what exactly happened here?".
• Traces: one request's path across services with timing, good for "where is the time spent?".
• Use counters for counts; do not log a line per event to count it.
• Keep metric labels low-cardinality (route, status), never user or order ids.