What methods of monitoring web applications in production environment have you used or know?

• Logging: Collection and analysis of system logs and application logs.
  • Using the standard logging library.
  • Applying ELK Stack (Elasticsearch, Logstash, Kibana) or Loki/Prometheus with Grafana for log aggregation and analysis.
• Metrics Monitoring: Tracking key performance indicators.
  • System metrics: CPU, RAM, disk space, network traffic (using node_exporter, collectd).
  • Application metrics: Response time, request count, errors, memory usage (using Prometheus client libraries, Datadog, New Relic).
  • Using Prometheus, Graphite, InfluxDB for collecting and storing metrics, Grafana for visualization.
• Request tracing (Distributed Tracing): Tracking the request path across different system components.
  • Using OpenTelemetry, Jaeger, Zipkin.
• Availability monitoring (Uptime Monitoring): Checking application availability externally.
  • Using Pingdom, Uptime Robot, Zabbix.
• Error monitoring (Error Tracking): Collecting and analyzing errors occurring in the application.
  • Using Sentry, Rollbar.
• Synthetic monitoring: Simulating user actions to verify functionality.
  • Using Selenium with tests that run periodically.
• Real User Monitoring (RUM): Collecting performance data from real users' browsers.
  • Using Google Analytics, Datadog RUM.

Examples of tools:

• Metrics collection and storage: Prometheus, Graphite, InfluxDB
• Visualization: Grafana
• Logging: ELK Stack (Elasticsearch, Logstash, Kibana), Loki
• Tracing: Jaeger, Zipkin, OpenTelemetry
• Error monitoring: Sentry, Rollbar
• Comprehensive platforms: Datadog, New Relic, AppDynamics

Sample code for collecting metrics using prometheus_client:

# main.py
from prometheus_client import start_http_server, Summary
import random
import time

# Creating a metric to track request processing time
REQUEST_TIME = Summary('request_processing_seconds', 'Request processing time')

@REQUEST_TIME.time()
def process_request(t):
    """Simulates request processing with delay"""
    time.sleep(t)

if __name__ == '__main__':
    # Starts an HTTP server to expose metrics on port 8000
    start_http_server(8000)
    print("Metrics server started on port 8000")

    while True:
        # Simulate request processing
        process_request(random.random() * 5)