What methods and tools can be used to monitor the stability and performance of an application in real-time?

To monitor the stability and performance of an application in real-time, various methods and tools are used:

1. Metrics monitoring — collecting data on CPU load, memory usage, response time, request count, and errors.
2. Logging — recording events and errors for later analysis.
3. Tracing — tracking the execution of requests across different components.

Popular tools:

• Prometheus + Grafana — for metrics collection and visualization.
• New Relic, Datadog, AppDynamics — commercial solutions for monitoring and alerting.
• Sentry — for error and exception tracking.
• Elastic Stack (ELK) — centralized logging and analysis.

Example of simple resource monitoring using psutil library in Python:

import psutil
import time

while True:
    cpu = psutil.cpu_percent(interval=1)
    mem = psutil.virtual_memory().percent
    print(f"CPU: {cpu}%, Memory: {mem}%")
    time.sleep(5)

This script helps track resource usage in real-time.