Synthetic Monitoring

Detailed explanation

Synthetic monitoring, also known as proactive monitoring or active monitoring, is a testing technique used to simulate user activity on a website, application, or API to proactively identify and resolve performance and availability issues before they impact real users. Unlike real user monitoring (RUM), which collects data from actual user interactions, synthetic monitoring uses scripts or bots to mimic user behavior and continuously monitor the system's performance from various locations and at different times.

The core principle behind synthetic monitoring is to create a controlled environment where tests are executed regularly to measure key performance indicators (KPIs) such as response time, availability, and functionality. By simulating user journeys, synthetic monitoring can detect problems like slow page load times, broken links, API failures, and other issues that can degrade the user experience.

Practical Implementation

Implementing synthetic monitoring involves several key steps:

1. Define User Journeys: Identify the critical user paths or transactions that are most important for your application. This could include logging in, searching for a product, adding items to a cart, or completing a checkout process.

2. Create Monitoring Scripts: Develop scripts or use monitoring tools to simulate these user journeys. These scripts should mimic the actions a real user would take, such as clicking buttons, entering data, and navigating between pages.

   For example, using a tool like Selenium, you might create a script to automate the login process:

   from selenium import webdriver
   from selenium.webdriver.common.by import By
   from selenium.webdriver.chrome.options import Options
    
   # Configure Chrome options for headless execution
   chrome_options = Options()
   chrome_options.add_argument("--headless")
   chrome_options.add_argument("--no-sandbox")
   chrome_options.add_argument("--disable-dev-shm-usage")
    
   # Initialize the Chrome driver
   driver = webdriver.Chrome(options=chrome_options)
    
   # Navigate to the login page
   driver.get("https://example.com/login")
    
   # Enter username and password
   username_field = driver.find_element(By.ID, "username")
   password_field = driver.find_element(By.ID, "password")
   username_field.send_keys("testuser")
   password_field.send_keys("password123")
    
   # Click the login button
   login_button = driver.find_element(By.ID, "login-button")
   login_button.click()
    
   # Verify successful login
   try:
       assert "Welcome" in driver.page_source
       print("Login successful!")
   except AssertionError:
       print("Login failed!")
    
   # Close the browser
   driver.quit()

   This script automates the login process and verifies that the login was successful.

3. Configure Monitoring Locations: Choose the locations from which you want to monitor your application. This is important because performance can vary depending on the user's location and network conditions. Select locations that represent your key user demographics.

4. Schedule Monitoring Tests: Set up a schedule for running your monitoring scripts. The frequency of tests will depend on the criticality of your application and the level of detail you need. More frequent tests provide more granular data and faster detection of issues.

5. Analyze Monitoring Data: Review the data collected by your monitoring tests to identify performance bottlenecks, availability issues, and other problems. Look for trends and patterns that can help you proactively address potential issues.

6. Set Up Alerts: Configure alerts to notify you when performance thresholds are exceeded or when availability issues are detected. This allows you to respond quickly to problems and minimize the impact on users.

Best Practices

• Simulate Realistic User Behavior: Ensure that your monitoring scripts accurately reflect how real users interact with your application. This includes simulating different types of users, devices, and network conditions.

• Monitor Key Performance Indicators (KPIs): Focus on monitoring the KPIs that are most important for your application, such as response time, availability, error rate, and throughput.

• Use Multiple Monitoring Locations: Monitor your application from multiple locations to get a comprehensive view of performance across different regions and networks.

• Integrate with Existing Monitoring Tools: Integrate synthetic monitoring with your existing monitoring tools to get a unified view of your application's performance.

• Regularly Review and Update Monitoring Scripts: As your application evolves, it's important to review and update your monitoring scripts to ensure they accurately reflect the current user experience.

• Monitor Third-Party Services: If your application relies on third-party services, such as APIs or CDNs, monitor their performance as well. Issues with third-party services can impact your application's performance and availability.

Common Tools

Several tools are available for implementing synthetic monitoring, including:

• Selenium: A popular open-source framework for automating web browser interactions.

• Puppeteer: A Node.js library for controlling headless Chrome or Chromium.

• Playwright: A Node.js library to automate Chromium, Firefox and WebKit with a single API.

• New Relic Synthetics: A cloud-based synthetic monitoring tool that allows you to create and run synthetic tests from various locations.

• Datadog Synthetic Monitoring: A synthetic monitoring solution that integrates with Datadog's other monitoring tools.

• Uptrends: A web performance monitoring tool that offers synthetic monitoring capabilities.

• Pingdom: A website monitoring service that includes synthetic monitoring features.

• Grafana k6: An open-source load testing tool that can also be used for synthetic monitoring.

Synthetic monitoring is a valuable tool for ensuring the performance and availability of your applications. By proactively identifying and resolving issues before they impact real users, you can improve the user experience, reduce downtime, and maintain a competitive edge.

Further reading

• New Relic Synthetics Documentation
• Datadog Synthetic Monitoring Documentation
• Selenium Documentation
• Puppeteer Documentation
• Playwright Documentation