Concurrency in Spring WebFlux | Baeldung

1. Introduction

In this tutorial, we’ll explore concurrency in reactive programs written with Spring WebFlux.

We’ll begin by discussing concurrency in relation to reactive programming. After that, we’ll explore how Spring WebFlux offers concurrency abstractions over different reactive server libraries.

2. The Motivation for Reactive Programming

A typical web application comprises of several complex, interacting parts. Many of these interactions are blocking in nature like, for example, those involving a database call to fetch or update data.  Several others, however, are independent and can be performed concurrently, possibly in parallel.

For instance, two user requests to a web server can be handled by different threads. On a multi-core platform, this has an obvious benefit in terms of the overall response time. Hence, **this model of concurrency is known as the thread-per-request model**:

In the diagram above, each thread handles a single request at a time.

While thread-based concurrency solves a part of the problem for us, it does nothing to address the fact that most of our interactions within a single thread are still blocking. Moreover, the native threads we use to achieve concurrency in Java come at a significant cost in terms of context switches.

Meanwhile, as web applications face more and more requests, the thread-per-request model starts to fall short of expectations.

Consequently, what we need is a concurrency model which can help us handle increasingly more requests with relatively less number of threads. This is one of the primary motivations for adopting reactive programing.

3. Concurrency in Reactive Programming

Reactive programming helps us structure the program in terms of data flows and the propagation of change through them. Hence, in a completely non-blocking environment, this can enable us to achieve higher concurrency with better resource utilization.

However, is reactive programming a complete departure from thread-based concurrency? While this is a strong statement to make, reactive programming certainly has a very different approach to the usage of threads to achieve concurrency. So, the fundamental difference that reactive programming brings on is asynchronicity.

In other words, the program flow transforms from a sequence of synchronous operations, into an asynchronous stream of events.

For instance, under the reactive model, a read call to the database does not block the calling thread while data is fetched. The call immediately returns a publisher that others can subscribe to. The subscriber can process the event after it occurs and may even further generate events itself:

Above all, reactive programming does not emphasize on which thread events should be generated and consumed. Emphasis is, rather, on structuring the program as an asynchronous event stream.

The publisher and subscriber here do not need to be part of the same thread. This helps us in getting better utilization of available threads and hence higher overall concurrency.

4. Event Loop

There are several programming models that describe a reactive approach to concurrency.

In this section, we’ll examine a few of them to understand how reactive programming achieves higher concurrency with fewer threads.

One of such reactive asynchronous programming model for servers is the event loop model:

#reactive #spring #webflux

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Concurrency in Spring WebFlux | Baeldung

1. Introduction

In this tutorial, we’ll explore concurrency in reactive programs written with Spring WebFlux.

We’ll begin by discussing concurrency in relation to reactive programming. After that, we’ll explore how Spring WebFlux offers concurrency abstractions over different reactive server libraries.

2. The Motivation for Reactive Programming

A typical web application comprises of several complex, interacting parts. Many of these interactions are blocking in nature like, for example, those involving a database call to fetch or update data.  Several others, however, are independent and can be performed concurrently, possibly in parallel.

For instance, two user requests to a web server can be handled by different threads. On a multi-core platform, this has an obvious benefit in terms of the overall response time. Hence, **this model of concurrency is known as the thread-per-request model**:

In the diagram above, each thread handles a single request at a time.

While thread-based concurrency solves a part of the problem for us, it does nothing to address the fact that most of our interactions within a single thread are still blocking. Moreover, the native threads we use to achieve concurrency in Java come at a significant cost in terms of context switches.

Meanwhile, as web applications face more and more requests, the thread-per-request model starts to fall short of expectations.

Consequently, what we need is a concurrency model which can help us handle increasingly more requests with relatively less number of threads. This is one of the primary motivations for adopting reactive programing.

3. Concurrency in Reactive Programming

Reactive programming helps us structure the program in terms of data flows and the propagation of change through them. Hence, in a completely non-blocking environment, this can enable us to achieve higher concurrency with better resource utilization.

However, is reactive programming a complete departure from thread-based concurrency? While this is a strong statement to make, reactive programming certainly has a very different approach to the usage of threads to achieve concurrency. So, the fundamental difference that reactive programming brings on is asynchronicity.

In other words, the program flow transforms from a sequence of synchronous operations, into an asynchronous stream of events.

For instance, under the reactive model, a read call to the database does not block the calling thread while data is fetched. The call immediately returns a publisher that others can subscribe to. The subscriber can process the event after it occurs and may even further generate events itself:

Above all, reactive programming does not emphasize on which thread events should be generated and consumed. Emphasis is, rather, on structuring the program as an asynchronous event stream.

The publisher and subscriber here do not need to be part of the same thread. This helps us in getting better utilization of available threads and hence higher overall concurrency.

4. Event Loop

There are several programming models that describe a reactive approach to concurrency.

In this section, we’ll examine a few of them to understand how reactive programming achieves higher concurrency with fewer threads.

One of such reactive asynchronous programming model for servers is the event loop model:

#reactive #spring #webflux

Spring vs Spring BooDifference Between Spring and Spring Boot

As an extension of the Spring Framework, Spring Boot is widely used to make development on Spring faster, more efficient and convenient. In this article, we will look at some of the parameters were using Spring Boot can drastically reduce the time and effort required in application development.

What is Spring?

Spring Boot

Difference between Spring and Spring Boot

Advantages of Spring Boot over Spring

Conclusion

#full stack development #spring #spring and spring boot #spring boot

Spring Native turns Spring apps into native executables

Spring Native beta release leverages GraalVM to compile Spring Java and Kotlin applications to native images, reducing startup time and memory overhead compared to the JVM.

Spring Native, for compiling Spring Java applications to standalone executables called native images, is now available as a beta release. Native images promise faster startup times and lower runtime memory overhead compared to the JVM.

Launched March 11 and available on start.spring.io, the Spring Native beta compiles Spring applications to native images using the GraalVM multi-language runtime. These standalone executables offer benefits including nearly instant startup (typically fewer than 100ms), instant peak performance, and lower memory consumption, at the cost of longer build times and fewer runtime optimizations than the JVM.

#spring native turns spring apps into native executables #spring native #spring #native executables #spring apps

Spring Framework Tutorial

What is the spring framework in Java?

The spring framework is one of the most versatile frameworks in java which is used to bring down the complexity of the development of enterprise-grade applications. The first production release of the spring framework was in March 2004 and since then, this robust and open-source framework has gained tremendous popularity, so much so that it is often referred to by developers all around the world as the “framework of frameworks”. Spring is a loosely coupled, open-source application framework of java. It is lightweight and the inversion of the control container for the Java platform. A large number of Java applications use the core features of the spring framework. In addition to that, extensions have also been developed to allow developers to develop Web Applications on top of the Java Enterprise Edition platform.

#spring #spring-framework #java #spring framework tutorial #why should one learn about the spring framework? #what is the spring framework in java?

Concurrency in Spring WebFlux

1. Introduction

In this tutorial, we’ll explore concurrency in reactive programs written with Spring WebFlux.

We’ll begin by discussing concurrency in relation to reactive programming. After that, we’ll explore how Spring WebFlux offers concurrency abstractions over different reactive server libraries.

2. The Motivation for Reactive Programming

A typical web application comprises of several complex, interacting parts. Many of these interactions are blocking in nature like, for example, those involving a database call to fetch or update data.  Several others, however, are independent and can be performed concurrently, possibly in parallel.

For instance, two user requests to a web server can be handled by different threads. On a multi-core platform, this has an obvious benefit in terms of the overall response time. Hence, **this model of concurrency is known as the thread-per-request model**:

#reactive #spring #webflux