Eclipse Jemo presentation at Community Day, EclipseCon Europe 2019. Speaker: Yannis Theocharis

1. Eclipse Jemo
ECE 2019, Cloud Native Java, Community Day
Yannis Theocharis, Eclipse Jemo Committer
e-mail: ytheohar@gmail.com
twitter: @ytheohar

2. What is Jemo?
● Cloud Native Java Runtime
○ Acts as an application server for cloud native Java applications
● Homogenous distributed computing platform
○ A set of identical Jemo docker containers running on Kubernetes, where each container is
able to respond to any app deployed in the platform
● Function as a service execution environment
○ Jemo offers build-in development patterns to respond to events, e.g. HTTP calls, messages
and scheduled tasks.
● Multi-cloud runtime environment
○ “Write once, run everywhere”. CSP services are abstracted away so that Jemo apps code is
CSP agnostic.

3. Jemo Distinctive Properties
● Deployment of the Jemo runtime on the cloud is completely independent from
deployment of Jemo apps on the Jemo runtime.
○ Jemo containers are deployed to Kubernetes prior to any app deployed on Jemo.
● Jemo containers are stateless
○ State is loaded from the CSP services Jemo is deployed on.
● The JVM starts before any app is deployed
○ JVM starts when each Jemo container starts and many apps can run concurrently within the
same container - greater density.
● Each Jemo container can run many apps concurrently
○ Responding to events, e.g. HTTP calls, a Jemo container loads the code of an app serves the
request and if no request comes for the same app in 10 minutes the app is unloaded from the
container.

4. Jemo Dev & Devops Tools
● Local Debugging
○ A cluster running on the public cloud can be easily extended to your desktop by running a local
Jemo instance and debug using your IDE with all the context of the cloud environment.
● Jemo maven archetype
○ Creates a Jemo app with examples of code implementing the Jemo development patterns.
● Jemo maven plugin
○ Deploy a Jemo app on a cluster.
● Devops tools
○ Compile, test and deploy a Jemo app stored on github.
○ Monitor/pause/restart/delete apps.
● Cloud Native
○ Setup wizard sets up a new Kubenetes cluster of Jemo containers on AWS, Azure or GCP, by
generating Terraform templates.

5. Cloud Provider Service Abstraction
AWS Azure GCP
File Storage S3 Storage Account Cloud Storage
NoSQL DynamoDB CosmosDB Cloud Datastore
Messaging SQS Storage Account
Queues
Cloud Datastore
Logging Cloudwatch Log Analytics
Workspace
StackDriver Logging

6. Resources
● Jemo website: https://www.eclipse.org/jemo/
● Jemo project: https://projects.eclipse.org/projects/technology.jemo
● Github repo: https://github.com/eclipse/jemo
● Docker hub: https://hub.docker.com/r/eclipse/jemo/tags
● Blogpost: https://medium.com/@ytheohar/cloud-provider-agnostic-development-with-eclipse-jemo-605b4d0b6ba7

7. Demo - Set up a local jemo instance
> git clone https://github.com/eclipse/jemo.git
> cd jemo/core
> mvn package -DskipTests
> java -jar target/jemo-1.0.7.jar

8. Demo - Create a Jemo app
mvn archetype:generate
-DarchetypeGroupId=org.eclipse.jemo
-DarchetypeArtifactId=eclipse-jemo-maven-archetype
-DarchetypeVersion=1.2
-DgroupId=com.example
-DartifactId=jemo-app-demo
-Dversion=1.0
-DpluginId=10
-DjemoEndpoint=http://localhost
-Dusername=system.administrator@jemo.eclipse.org
-Dpassword=3906e814-7604-4ba2-b233-888409541e9b

9. Demo - Deploy a Jemo app
> mvn deploy