diff --git a/core-java-modules/core-java-perf-2/README.md b/core-java-modules/core-java-perf-2/README.md
index 0d8c2d798e..8911c687a0 100644
--- a/core-java-modules/core-java-perf-2/README.md
+++ b/core-java-modules/core-java-perf-2/README.md
@@ -5,3 +5,4 @@ This module contains articles about performance of Java applications
 ### Relevant Articles:
 - [Possible Root Causes for High CPU Usage in Java](https://www.baeldung.com/java-high-cpu-usage-causes)
 - [External Debugging With JMXTerm](https://www.baeldung.com/java-jmxterm-external-debugging)
+- [Create and Detect Memory Leaks in Java](https://www.baeldung.com/java-create-detect-memory-leaks)
diff --git a/core-java-modules/core-java-perf-2/pom.xml b/core-java-modules/core-java-perf-2/pom.xml
index a9408ca385..a44f6aa8c1 100644
--- a/core-java-modules/core-java-perf-2/pom.xml
+++ b/core-java-modules/core-java-perf-2/pom.xml
@@ -13,4 +13,11 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>net.datafaker</groupId>
+            <artifactId>datafaker</artifactId>
+            <version>1.6.0</version>
+        </dependency>
+    </dependencies>
 </project>
\ No newline at end of file
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/LapsedListenerRunner.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/LapsedListenerRunner.java
new file mode 100644
index 0000000000..50da98e6c4
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/LapsedListenerRunner.java
@@ -0,0 +1,35 @@
+package com.baeldung.lapsedlistener;
+
+import static com.baeldung.lapsedlistener.UserGenerator.generateUser;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LapsedListenerRunner {
+
+    private static final Logger logger = LoggerFactory.getLogger(LapsedListenerRunner.class);
+    private static final MovieQuoteService movieQuoteService = new MovieQuoteService();
+
+    static {
+        movieQuoteService.start();
+    }
+
+public static void main(String[] args) {
+    while (true) {
+        User user = generateUser();
+        logger.debug("{} logged in", user.getName());
+        user.subscribe(movieQuoteService);
+        userUsingService();
+        logger.debug("{} logged out", user.getName());
+    }
+}
+
+    private static void userUsingService() {
+        try {
+            Thread.sleep(10);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+}
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/MovieQuoteService.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/MovieQuoteService.java
new file mode 100644
index 0000000000..95240bbbd5
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/MovieQuoteService.java
@@ -0,0 +1,47 @@
+package com.baeldung.lapsedlistener;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import net.datafaker.Faker;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MovieQuoteService implements Subject {
+
+    private static final Logger logger = LoggerFactory.getLogger(MovieQuoteService.class);
+    private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
+    private final List<Observer> observers = new ArrayList<>();
+    private final Faker faker = new Faker();
+
+    @Override
+    public void attach(Observer observer) {
+        logger.debug("Current number of subscribed users: {}", observers.size());
+        observers.add(observer);
+    }
+
+    @Override
+    public void detach(Observer observer) {
+        observers.remove(observer);
+    }
+
+    @Override
+    public void notifyObservers() {
+        String quote = faker.movie().quote();
+        logger.debug("New quote: {}", quote);
+        for (Observer observer : observers) {
+            logger.debug("Notifying user: {}", observer);
+            observer.update(quote);
+        }
+    }
+
+    public void start() {
+        scheduler.scheduleAtFixedRate(this::notifyObservers, 0, 1, TimeUnit.SECONDS);
+    }
+
+    public int numberOfSubscribers() {
+        return observers.size();
+    }
+}
\ No newline at end of file
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Observer.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Observer.java
new file mode 100644
index 0000000000..2c4ccf9e06
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Observer.java
@@ -0,0 +1,9 @@
+package com.baeldung.lapsedlistener;
+
+public interface Observer {
+    void update(String latestNews);
+
+    void subscribe(Subject subject);
+
+    void unsubscribe(Subject subject);
+}
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Subject.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Subject.java
new file mode 100644
index 0000000000..141a7662a7
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/Subject.java
@@ -0,0 +1,9 @@
+package com.baeldung.lapsedlistener;
+
+public interface Subject {
+    void attach(Observer observer);
+
+    void detach(Observer observer);
+
+    void notifyObservers();
+}
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/User.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/User.java
new file mode 100644
index 0000000000..0ed0a32a01
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/User.java
@@ -0,0 +1,70 @@
+package com.baeldung.lapsedlistener;
+
+public class User implements Observer {
+
+    private final String name;
+    private final String email;
+    private final String phone;
+    private final String street;
+    private final String city;
+    private final String state;
+    private final String zipCode;
+
+    public User(String name, String email, String phone, String street, String city, String state, String zipCode) {
+        this.name = name;
+        this.email = email;
+        this.phone = phone;
+        this.street = street;
+        this.city = city;
+        this.state = state;
+        this.zipCode = zipCode;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public String getStreet() {
+        return street;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public String getState() {
+        return state;
+    }
+
+    public String getZipCode() {
+        return zipCode;
+    }
+
+    @Override
+    public void update(final String quote) {
+        // user got updated with a new quote
+    }
+
+    @Override
+    public void subscribe(final Subject subject) {
+        subject.attach(this);
+    }
+
+    @Override
+    public void unsubscribe(final Subject subject) {
+        subject.detach(this);
+    }
+
+    @Override
+    public String toString() {
+        return "User [name=" + name + "]";
+    }
+}
diff --git a/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/UserGenerator.java b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/UserGenerator.java
new file mode 100644
index 0000000000..acdb7d7af7
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/main/java/com/baeldung/lapsedlistener/UserGenerator.java
@@ -0,0 +1,23 @@
+package com.baeldung.lapsedlistener;
+
+import net.datafaker.Faker;
+
+public class UserGenerator {
+
+    private UserGenerator() {
+    }
+
+    private static final Faker faker = new Faker();
+
+    public static User generateUser() {
+        String name = faker.name().fullName();
+        String email = faker.internet().emailAddress();
+        String phone = faker.phoneNumber().cellPhone();
+        String street = faker.address().streetAddress();
+        String city = faker.address().city();
+        String state = faker.address().state();
+        String zipCode = faker.address().zipCode();
+        return new User(name, email, phone, street, city, state, zipCode);
+    }
+
+}
\ No newline at end of file
diff --git a/core-java-modules/core-java-perf-2/src/test/java/com/baeldung/lapsedlistener/MovieQuoteServiceTest.java b/core-java-modules/core-java-perf-2/src/test/java/com/baeldung/lapsedlistener/MovieQuoteServiceTest.java
new file mode 100644
index 0000000000..90c96cba1b
--- /dev/null
+++ b/core-java-modules/core-java-perf-2/src/test/java/com/baeldung/lapsedlistener/MovieQuoteServiceTest.java
@@ -0,0 +1,24 @@
+package com.baeldung.lapsedlistener;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class MovieQuoteServiceTest {
+
+    @Test
+    void whenSubscribeToService_thenServiceHasOneSubscriber() {
+        MovieQuoteService service = new MovieQuoteService();
+        service.attach(UserGenerator.generateUser());
+        assertEquals(1, service.numberOfSubscribers());
+    }
+
+    @Test
+    void whenUnsubscribeFromService_thenServiceHasNoSubscribers() {
+        MovieQuoteService service = new MovieQuoteService();
+        User user = UserGenerator.generateUser();
+        service.attach(user);
+        service.detach(user);
+        assertEquals(0, service.numberOfSubscribers());
+    }
+}
\ No newline at end of file