Problem Let’s say you are starting your Spring Boot application and your (Spring Boot) application is trying to connect to vhost (virtual host) ‘xyz’ that does not exist in RabbitMQ server. So, you are getting error – access to vhost ‘xyz’ refused for use ‘guest’. By default, the user which is used to connect to RabbitMQ is ‘guest’….

Posted in RabbitMQ

RabbitMQ – access to vhost ‘xyz’ refused for user ‘guest’

Introduction In this tutorial I am going to explain about few common startup problems or errors of RabbitMQ server after a fresh installation. I am using 3.6.1 version of the RabbitMQ message broker. RabbitMQ Startup Errors You might have faced the following errors during starting the RabbitMQ message broker after installation in your system. Starting…

Posted in RabbitMQ

Fix RabbitMQ Startup Errors After Installation

Introduction The example I will show you here about the asynchronous communication among microservices or how microservices communicate asynchronously among themselves. A microservices-based application is a distributed system running on multiple processes or services, usually even across multiple servers or hosts. Each service instance is typically a process. Therefore, services must interact using an inter-process…

Posted in Kafka Microservices Spring Boot

Microservices Asynchronous Communication – Push Notifications

Introduction Here in this tutorial I am going to show you how to work with Apache Kafka consumer and broker failover in multi-broker clusters. Kafka is a distributed event streaming platform that lets you read, write, store, and process events (also called records or messages in the documentation) across many machines. Example events are payment…

Posted in Kafka

Apache Kafka Consumer and Broker Failover in Multi-Broker Clusters

Here I am going to build an application to show how to use Spring Cloud Bus. Let’s say you have multiple applications reading properties using Spring Cloud Config from centralized configuration files (for example, from Git repository). Spring Cloud Config is where you can have not only your all configurations centrally managed but also you…

Posted in Kafka Spring Boot Spring Cloud

Spring Cloud Bus Example

Introduction In this tutorial I am going to show you how to use Python client to work with Apache kafka distributed stream processing system. I will create Kafka producer and consumer examples using Python language. KafkaConsumer is a high-level message consumer that consumes records from a kafka cluster. The consumer is not thread safe and…

Posted in Kafka Python

Python Client for Apache Kafka Producer and Consumer

In this tutorial we will see an example of event driven streaming using Spring Cloud Stream and Apache Kafka streaming platform. How do we deal with some events, such as, a new user has registered to a portal, an order was placed, a file has been uploaded etc? Let’s say when an order was placed…

Posted in Kafka Microservices Spring Boot Spring Cloud

Event Driven Streaming using Spring Cloud Stream and Apache Kafka

Introduction In this tutorial I will show you how to work with Apache Kafka Streams for building Real Time Data Processing with STOMP over Websocket using Spring Boot and Angular 8. We will see how to build push notifications using Apache Kafka, Spring Boot and Angular 8. We need to provide some basic things that…

Posted in Angular Kafka Spring Boot WebSocket

Apache Kafka Streams for building Real Time Data Processing with STOMP over WebSocket using Spring Boot and Angular 8

Introduction In this tutorial I will show you how to produce and send message using Apache Kafka and Spring Boot. Apache Kafka is supported by providing auto-configuration of the spring-kafka project. Kafka configuration is controlled by external configuration properties in spring.kafka.*. I will show you how to build this application using both maven and gradle…

Posted in Kafka

How to produce and consume message using Apache Kafka and Spring Boot

Introduction In this guide I will tell you how to setup and work with publish subscribe domain in Apache Kafka in windows environment. I am not going to tell you about Kafka and you will find very good documentation on this here. Kafka works on publish subscribe domain and this tutorial will show you how…

Posted in Kafka

How to setup and work with Publish Subscribe domain in Apache Kafka in Windows Environment

Introduction We will see an example here how to publish and subscribe message onto MQTT (Mosquitto) using Spring Boot framework. We had seen in our previous example how to publish and subscribe message using Mosquitto client – MQTT.fx. So here we are going to ingrate Spring application with MQTT broker through Spring integration framework, though…

Posted in JMS Mosquitto Spring Boot

Publish Subscribe Message onto MQTT using Spring Boot

Introduction Here we will see how to publish subscribe message using Mosquitto client – MQTT.fx. You can use any server side technologies such as Java, Spring, Python etc. to publish and subscribe message into MQTT topic but here we will use MQTT client, which is downloadable for various operating system, to publish or to subscribe…

Posted in Mosquitto

Publish Subscribe Message using Mosquitto Client – MQTT.fx