Spring Boot hot deployment in production - spring

I have multiple spring boot based micro services. Can we enable hot deployment of those micro services in production environment. If yes how we can do it. Please note : currently we don't have docker. And though the services artifacts are jar, we can turn those to war.

Hot deployment is not a feature of Spring Boot so it's not correct to consider it configurable (enabled or disabled).
Hot deployment is a feature of application servers (tomcat, jboss, jetty, etc) where you deploy your WARs. If they supports hot deployment (most of them do!) then it's OK to replace WARs on-the-fly so they will be re-deployed.

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How do people host Spring Boot apps with WebFlux on Reactor Netty in production?

I know it's a vague question but that's because I am not clear enough on what people are doing to ask anything more specific. I currently run my own apps with the embedded reactor netty server for development and basically push the embedded server inside a jar to cloud foundry to run the embedded server in production.
What are the other ways out there to set up a production environment for reactive reactor netty apps that people are using, or any documentation you might have seen?
I'm no sure that there is any difference between hosting the reactive spring-webflux application and regular applications.
Spring boot creates a jar with everything bundled inside (netty or more old-school tomcat) - it doesn't matter.
Then you can take this and run it "as is" on your server (on-premise, cloud ec2 style whatever you have, this really depends on your organization) directly with java -jar app.jar
Or, if you have more advanced needs/setup:
"Containerize" the application and create a docker (usually, although there are alternatives) image that runs the spring boot application. and then deploy it on kubernetes cluster, for example. At this point you should really consult with your DevOps people so that they'll tell you what is the way of deployment in your organization.
Besides kubernetes cluster there are many other alternatives:
- cloud provider specific solutions, like ECS or Fargate in amazon AWS
- Docker Swarm to name a few
All these solutions are pretty advanced, allow auto-scaling, advanced liveness monitoring and so forth. As an organization you usually pick the one that meets your needs

Spring boot webservice to start and be discoverable when JBOSS EAP starts

We need to create independent spring boot web services for our apps which runs in JBOSS EAP. Can we do the below if its possible.
Spring Boot is typically deployed as a runnable jar but our apps are EAR deployed. Can we bootstrap / launch the spring boot listener / controller when the EAR application starts)
Can we register the services on start to facilitate automated discoverability of services (typically done with consul/ etcd/ zookeeper etc)
You can generate a WAR instead of a JAR and deploy this. If this is not ok you can put the WAR in an EAR
Read the docs: https://docs.spring.io/spring-boot/docs/current/reference/html/howto-traditional-deployment.html
Yes. If you have a service registry in place you can use this with Spring Cloud.
Please read the documentation:
https://spring.io/guides/gs/service-registration-and-discovery/

Cloud Foundry : Spring boot vs WAR file

I am new to the world of Cloud, CloudFoundry, Saas, PaaS, IaaS, etc.
So I have few very fundamental questions.
Who is better Spring boot or war file in terms of deploying an application or a service to a cloud using cloud foundry?
WHY ?
If I want to deploy my war file on a PaaS cloud then who kicks it off?
As in where is the server?
How will I know which server my war file is deployed to?
Is using Spring-boot with embeded tomcat for PaaS mandatory?
What if my application does not use spring-boot (no spring reference in pom as well) then can I deploy my application war file on cloud? How?
There is nothing like better in war or Spring boot jar. They both are underhood same things, where Spring boot jar manages the server embedded in it and war does not have that.
Cloud Foundry has something like BuildPacks. You need to define a buildpack when you do a cf push. If you select a java build pack it has the things required to run a war on server. It gets the Java, Tomcat Server and all other dependencies needed to run the war.
https://github.com/cloudfoundry/java-buildpack
Cloud foundry creates a droplet, which is basically the execution context with all required dependencies. This is used to run the actual VM on the cloud.
You need not know which server your war is deployed to. That is the basic idea behind the cloud deployment. It may be on a single/multiple VMs under the hood. So what you need to know is something called routes. Routes are the actual addresses to your apps. You need to create routes and bind them to your application, and later app can be accessed using the routes.
https://docs.cloudfoundry.org/devguide/deploy-apps/routes-domains.html#routes
No using embedded servers is not mandatory in Any Cloud PAAS. War can be directly deployed. All PAAS platforms has support for this. Cloud foundry way of doing this is through build packs.
CF : https://docs.cloudfoundry.org/buildpacks/
Heroku : https://devcenter.heroku.com/articles/java-webapp-runner
Any application/ non spring apps which is plain war or jar can be used to run on PAAS platforms.

Integrated deployment with profile management for set of Spring Boot microservices with maven

I have 7-8 microservices, in future this number can grow to 25-30. All these services are Spring boot REST services.
What is the best practice to have integrated build for all?
Also, for deployment purpose I have to switch between test and dev profile. How can I make it centralized instead of doing it for each service?
As microservices should be independent they should not be build or deployed together. Switching between test and dev profile could be performed by checking where the service is deployed with use of environment variables. More information e.g. here.

Spring Boot + Tomcat - Microservices solution

I'm planning to expose few microservices (~20 at this stage) using Spring Boot. I will be creating executable fat jars using the embededed Tomcat. The executable jar will be wrapped in Docker container and deployed to AWS.
In my case 20 jars will have 20 tomcat instances running at the same time. I'm concerned about the overhead of running so many tomcat instances in the production server. Is this a valid concern?
I was wondering if someone has used something similar configuration in production and can share their experience.
Any suggestions will be appreciated.
Thanks
JP
We currently use AWS and Spring Cloud / Spring Boot. Our stance is instances that require more resources receive their own EC2 instance. Services that can be deployed using Docker are deployed to Amazon ECS.
All of our deployments are fat jars using embedded Tomcat.
Not knowing the size of what you are calling a service makes this answer a little complicated. If you are worried about Tomcat's overhead why are you running these services in Docker containers? Ease of deployment?
If you do go the route of deploying multiple services to the same Tomcat instance, I would not define your setup as a microservices based configuration.
You may try to deploy all your services (webapps) into one or more tomcat instances. You may not include the Tomcat into war file. Example maven/spring configuration you may find here

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