eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
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Let's get started with a Microservice Architecture with Spring Cloud:

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eBook – Mockito – NPI EA (tag = Mockito)
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Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.

Get started with mocking and improve your application tests using our Mockito guide:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

>> Download the eBook

eBook – Reactive – NPI EA (cat=Reactive)
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Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:

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eBook – Java Streams – NPI EA (cat=Java Streams)
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Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

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eBook – Jackson – NPI EA (cat=Jackson)
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Do JSON right with Jackson

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eBook – HTTP Client – NPI EA (cat=Http Client-Side)
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Get the most out of the Apache HTTP Client

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eBook – Maven – NPI EA (cat = Maven)
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Get Started with Apache Maven:

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eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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eBook – RwS – NPI EA (cat=Spring MVC)
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Building a REST API with Spring?

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Course – LS – NPI EA (cat=Jackson)
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Get started with Spring and Spring Boot, through the Learn Spring course:

>> LEARN SPRING
Course – RWSB – NPI EA (cat=REST)
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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

>> The New “REST With Spring Boot”

Course – LSS – NPI EA (cat=Spring Security)
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Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.

I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.

You can explore the course here:

>> Learn Spring Security

Course – LSD – NPI EA (tag=Spring Data JPA)
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Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.

Get started with Spring Data JPA through the guided reference course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (cat=Spring Boot)
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Refactor Java code safely — and automatically — with OpenRewrite.

Refactoring big codebases by hand is slow, risky, and easy to put off. That’s where OpenRewrite comes in. The open-source framework for large-scale, automated code transformations helps teams modernize safely and consistently.

Each month, the creators and maintainers of OpenRewrite at Moderne run live, hands-on training sessions — one for newcomers and one for experienced users. You’ll see how recipes work, how to apply them across projects, and how to modernize code with confidence.

Join the next session, bring your questions, and learn how to automate the kind of work that usually eats your sprint time.

Course – LJB – NPI EA (cat = Core Java)
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Code your way through and build up a solid, practical foundation of Java:

>> Learn Java Basics

Partner – LambdaTest – NPI EA (cat= Testing)
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Distributed systems often come with complex challenges such as service-to-service communication, state management, asynchronous messaging, security, and more.

Dapr (Distributed Application Runtime) provides a set of APIs and building blocks to address these challenges, abstracting away infrastructure so we can focus on business logic.

In this tutorial, we'll focus on Dapr's pub/sub API for message brokering. Using its Spring Boot integration, we'll simplify the creation of a loosely coupled, portable, and easily testable pub/sub messaging system:

>> Flexible Pub/Sub Messaging With Spring Boot and Dapr

Partner – Diagrid – NPI (cat= Testing)
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Distributed systems often come with complex challenges such as service-to-service communication, state management, asynchronous messaging, security, and more.

Dapr (Distributed Application Runtime) provides a set of APIs and building blocks to address these challenges, abstracting away infrastructure so we can focus on business logic.

In this tutorial, we'll focus on Dapr's pub/sub API for message brokering. Using its Spring Boot integration, we'll simplify the creation of a loosely coupled, portable, and easily testable pub/sub messaging system:

>> Flexible Pub/Sub Messaging With Spring Boot and Dapr

1. Overview

In this article, we’ll explore distributed performance testing using JMeter.

2. What Is Distributed Performance Testing?

Distributed performance testing means using multiple systems with the master-slave configuration to test a web application or a server’s performance.

In this process, we’ll use a local client as a master that handles the test execution using multiple remote clients, and each remote client acting as a slave will execute the test on our target server.

Each slave system executes the load tests following the exact condition set by the master. Therefore, the distributed performance testing helps us achieve a higher number of concurrent users requesting the target server.

In simple terms, the outline of the distributed performance testing using JMeter will look like:

jmeter distributed

3. Setup

3.1. Prerequisites

We should follow a few prerequisites for a smooth setup and test run:

  • Multiple computers with JMeter installed on each
  • Firewalls on the systems are turned off, or required ports are opened for connection
  • All systems (master/slave) are on the same subnet
  • JMeter on each system can access the target server
  • Use the same version of Java and JMeter on all systems (master and slave)
  • For simplicity, disable the SSL for RMI

Now that we have our systems ready, let’s configure the slave and master systems.

3.2. Configure the Slave System

On the slave system, we’ll go to the jmeter/bin directory and execute the jmeter-server.bat file on Windows. Or, we can run the jmeter-server file on Unix.

3.3. Configure the Master System

On the master system, we’ll go to the jmeter/bin directory and edit the remote_hosts property in the jmeter.properties file to add IP addresses (comma-separated) of the slave systems:

remote_hosts=192.165.0.10,192.165.0.20,192.165.0.30

Here, we’ve added three slave systems.

So, by starting the JMeter (master) in the GUI mode, we can confirm all the slaves listed in the Run > Remote Start option:

jmeter slaves

 

That’s it! We’re ready to start the JMeter master system to execute tests on the target server using multiple clients.

4. Remote Testing

For remote testing, we can run JMeter in GUI mode for simplicity. However, we should run it using CLI mode when performing actual tests.

First, we’ll create a simple test plan in the master system that contains the HTTP Request sampler to request our baeldung.com server, and a View Results Tree listener.

4.1. Starting a Single Slave

Then, we can choose which slave system to run using GUI mode by using the Run > Remote Start option:

jmeter start slave

4.2. Starting All Slaves

Similarly, we can choose to run all slave systems by using the Run > Remote Start All option:

jmeter start all

Additionally, a few options are available to handle test execution on the slave systems like Remote Stop, Remote Stop All, and Remote Shutdown All.

4.3. Test Results

Finally, we can see the test results in the local JMeter (master) once test execution finishes:

jmeter master results

Also, on the remote JMeter systems (slaves), we can find logs about the start/stop of the test execution:

Starting the test on host 192.165.0.10 @ Sun Oct 25 17:50:21 EET 2020
Finished the test on host 192.165.0.10 @ Sun Oct 25 17:50:25 EET 2020

5. Conclusion

In this quick tutorial, we’ve seen how to get started with distributed performance testing using JMeter.

First, we looked at a few prerequisites for a smooth setup and test run. Then, we configured our slaves and master systems for a distributed performance testing environment.

Last, we started the slave systems, ran tests from a master system, and observed the results.

Baeldung Pro – NPI EA (cat = Baeldung)
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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
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The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints. Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:

>> Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

Explore the eBook

Course – LS – NPI EA (cat=REST)

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Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (tag=Refactoring)
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Modern Java teams move fast — but codebases don’t always keep up. Frameworks change, dependencies drift, and tech debt builds until it starts to drag on delivery. OpenRewrite was built to fix that: an open-source refactoring engine that automates repetitive code changes while keeping developer intent intact.

The monthly training series, led by the creators and maintainers of OpenRewrite at Moderne, walks through real-world migrations and modernization patterns. Whether you’re new to recipes or ready to write your own, you’ll learn practical ways to refactor safely and at scale.

If you’ve ever wished refactoring felt as natural — and as fast — as writing code, this is a good place to start.

eBook Jackson – NPI EA – 3 (cat = Jackson)