Reactive MongoDB with Spring boot

MongoDB has changed a lot over the last few years. I have not used it for more than eight years in production now. I recently need to use MongoDB as a multi-purpose data store. It surprised me a lot with the new features, but I was slightly disappointed with the problems of read and write concerns at default settings.  However, you can set it to a majority or a higher level to achieve casual consistency. In this post we are going to cover how to create a spring boot service, connect to Mongo DB with a reactive driver, and perform some queries. I used the freemium Mongo Atlas by signing up and set up a simple cluster on AWS. It is easy to sign up and we can load sample datasets as well. It may take a while to set up the data. Once it is done, head to start.spring.io, add webflux, reactive mongo, and generate the code. If you want to use Lombok, please add that as well. Part 1 – Basics First, we will look at the ReactiveMongoRepository, which is extended from ReactiveCrudRepository. If you’re already familiar with the repository pattern and used spring-data before, then there is

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Developing reactive microservice using Springboot 2

Reactive Spring is based on the project reactor for building non-blocking applications using the spring platform and spring cloud frameworks. Three important interfaces available in Reactor are Publisher, Subscriber, and Processor. Publisher – source of the data Subscriber – One which receives data asynchronously Processor – nothing but a publisher which is also a subscriber (most of the time we won’t need this) Reactor introduces reactive types which implement the Publisher interface namely Flux and Mono. Flux – represents multiple sequences of a result 0…N (many items) which suggests Flux is a standard publisher Mono – As the name suggests, represents single sequence of a result either an empty result or one result 0…1 which suggests Mono will emit at most one item Starting from Spring 5 and Spring Boot 2 reactive core is completely supported and provides an excellent long-awaited alternative to Akka Streams. If you are coming from a spring background and uses it extensively there is no reason why you shouldn’t try this. However, it is great for people who begin with Spring platform as well. This post is hugely inspired by Josh Long’s webinar on Reactive streams which you can find here. We are going to

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