Spring Security 6 & JWT Authentication · Lesson

Logging and Monitoring Security Events

Implement robust logging and monitoring strategies to detect and respond to security incidents effectively.

Logging and Monitoring Security Events is a free Spring Security 6 & JWT Authentication lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Spring Security 6 & JWT Authentication learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Why Log Security Events?

Security logging is like having a digital security camera for your application. It records important events, helping you understand what's happening within your system.

These logs are crucial for detecting malicious activities, troubleshooting issues, and meeting compliance requirements. Without proper logging, it's nearly impossible to know if your system is under attack or has been compromised.

Understanding Spring Security Events

Spring Security publishes various events when something significant happens, especially during authentication and authorization. These events are part of Spring's ApplicationEvent system.

Authentication Events: Fired during login attempts (success, failure).
Authorization Events: Fired when access is granted or denied to resources.
Session Events: Fired when sessions are created or destroyed.

By listening to these events, we can capture detailed security information.

Configuring Basic Logging

Spring Boot uses common logging frameworks like Logback by default. You can configure logging levels in your application.properties or application.yml file.

To see detailed Spring Security logs, you can increase the logging level for specific packages. For example, setting logging.level.org.springframework.security=DEBUG can reveal a lot of internal security operations.

# application.properties
logging.level.org.springframework.security=DEBUG
logging.level.org.springframework.web=INFO
logging.level.com.coddykit=DEBUG

Creating a Custom Event Listener

We can create custom listeners to react to Spring Security events. This is perfect for custom logging, sending alerts, or updating user accounts (e.g., locking an account after too many failed attempts).

All authentication events extend AbstractAuthenticationEvent. Common ones include AuthenticationSuccessEvent and AuthenticationFailureBadCredentialsEvent.

package com.coddykit.security;

import org.springframework.context.ApplicationListener;
import org.springframework.security.authentication.event.AuthenticationSuccessEvent;
import org.springframework.stereotype.Component;

@Component
public class MyAuthSuccessListener implements ApplicationListener<AuthenticationSuccessEvent> {

  @Override
  public void onApplicationEvent(AuthenticationSuccessEvent event) {
    System.out.println("Successful login by: " + event.getAuthentication().getName());
    // Log more details here, like IP address from request
  }
}

Demo: Handling Failed Logins

Let's create a runnable example for handling failed login attempts. We'll set up a basic Spring Security configuration and a listener for AuthenticationFailureBadCredentialsEvent. This helps detect brute-force attacks.

Try logging in with 'user' and 'wrongpassword' to see the failed login message.

package com.coddykit;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.event.AuthenticationFailureBadCredentialsEvent;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;
import org.springframework.security.web.SecurityFilterChain;

@SpringBootApplication
public class SecurityLoggingApp {
  public static void main(String[] args) {
    SpringApplication.run(SecurityLoggingApp.class, args);
  }

  @Bean
  public PasswordEncoder passwordEncoder() {
    return new BCryptPasswordEncoder();
  }

  @Bean
  public UserDetailsService userDetailsService(PasswordEncoder encoder) {
    UserDetails user = User.withUsername("user")
        .password(encoder.encode("password"))
        .roles("USER")
        .build();
    return new InMemoryUserDetailsManager(user);
  }

  @Bean
  public ApplicationListener<AuthenticationFailureBadCredentialsEvent> badCredentialsListener() {
    return event -> {
      String username = event.getAuthentication().getName();
      System.out.println("Failed login attempt for user: " + username);
      // In a real web app, you'd get the IP from the request context
      // For this simple example, event.getSource() gives the Authentication object
    };
  }

  @Configuration
  @EnableWebSecurity
  static class SecurityConfig {
    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
      http
        .authorizeHttpRequests(auth -> auth
          .anyRequest().authenticated()
        )
        .formLogin(form -> form
          .defaultSuccessUrl("/success", true)
          .permitAll()
        )
        .logout(logout -> logout
          .permitAll()
        );
      return http.build();
    }
  }
}

Key Data for Security Logs

When logging security events, it's vital to capture enough context without logging sensitive data (like plaintext passwords). Here's what to include:

Timestamp: When did the event occur?
User ID/Username: Who was involved?
Event Type: What happened (login, logout, access denied)?
Source IP Address: Where did the request come from?
Outcome: Was it successful or failed?
Error Details: Why did it fail (e.g., bad credentials, account locked)?

Centralizing Your Logs

For production environments, sending logs to a centralized logging system is a must. Tools like the ELK Stack (Elasticsearch, Logstash, Kibana), Splunk, or cloud-native solutions (AWS CloudWatch, Azure Monitor) collect logs from all your services.

This allows for easier searching, aggregation, and analysis of security events across your entire infrastructure. It helps spot patterns that might indicate a coordinated attack.

Proactive Monitoring & Alerts

Collecting logs is only half the battle; you also need to monitor them actively. Set up rules within your centralized logging system to detect suspicious activities:

Multiple failed login attempts from the same IP.
Successful logins from unusual geographical locations.
Frequent access denied events for a specific user or resource.
Unexpected user account changes.

Configure alerts (email, SMS, Slack) for these critical events so your team can respond quickly.

Log Retention Best Practices

How long should you keep security logs? This depends on regulatory requirements (like GDPR, HIPAA) and your organization's security policies. Typically, security logs are retained for a minimum of 90 days to several years.

Ensure your logging system has a robust retention policy, including secure storage, archiving, and eventual deletion of old logs to manage costs and compliance.

Security Logging Quiz

When implementing security event logging, which of the following should you generally AVOID logging directly in plain text?

Recap: Securing with Logs

In this lesson, we learned the importance of logging and monitoring security events in Spring Security. We covered how to use Spring's event system to capture authentication failures and successes, what key information to include in your logs, and the benefits of centralized logging and proactive alerting. Keeping a vigilant eye on your logs is a cornerstone of a strong security posture.

Frequently asked questions

Is the “Logging and Monitoring Security Events” lesson free?

Yes — the full text of “Logging and Monitoring Security Events” is free to read here on the web, and the Spring Security 6 & JWT Authentication course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Spring Security 6 & JWT Authentication course, upgrade to CoddyKit PRO.

What will I learn in “Logging and Monitoring Security Events”?

Implement robust logging and monitoring strategies to detect and respond to security incidents effectively. You practise Spring Security 6 & JWT Authentication with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Spring Security 6 & JWT Authentication?

No prior experience is required. Spring Security 6 & JWT Authentication on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Logging and Monitoring Security Events” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Spring Security 6 & JWT Authentication lesson?

Yes. Every Spring Security 6 & JWT Authentication lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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