Workflow Engine

A library adding workflow orchestration capability to your JVM applications. It is completely decentralized, just connect your database and give it a go.

Main benefits

• Decentralized - just a library to include in your service
• Fault-tolerant - at-least-once execution guarantees
• Efficient - intermediate state is persisted, no need to restart the whole workflow in case of failures
• Flexible - can be configured to efficiently process a large number of small workflows, or a small number of heavy workflows
• Scalable - horizontal scalability by sharding tables (coming soon)

How to run an example

H2

• Run the main() method inside Application.kt to start the service
• call localhost/demo and have fun looking at the logs

Mysql/Postgres

• Modify Application.createEngine() method: comment out h2, uncomment your preferred database config
• Run the main() method inside Application.kt to start the service
• call localhost/demo and have fun looking at the database

How to import an artifact

Artifacts are publicly available on Bintray Maven Repo.

Gradle

# build.gradle.kts

repositories {
    maven("https://dl.bintray.com/androiderob/workflow-engine")
}

dependencies {
    implementation("com.robkonarski.workflow:engine:0.0.5")
}

Activity requirements/recommendations

• Activities must be immutable - their inputs/outputs must not change
• Activities should be idempotent - since we can only provide at-least-once delivery guarantees
• If the Activity's input or output needs to change - copy the activity
• If the Activity is used in a workflow - don't delete it