Simple work flow is simple workflow framework, used for building simple full automation works orchestration by sync works, execute works in parallel.

There are lots of workflow open source, but lots of them are designed for enterprise's workflow that with human involved, such as activiti etc. they are a little complicated for cases that are simple such as just need to make several works execute in parallel, after these works done, then execute another patch works or work.

These scenarios for example:

##1. Build Load Test System

Can generate load in batch and by interval, such as first make 5 load agent to generate load together, after 5 mins, start another 5 load agents to generate load, etc.

##2. Build a continuous deployment system

Make upgrade an env as a workflow, then orchestrate the env upgrade by the workflow way. for example, for an env, there are 1 nginx server, 3 web servers, 2 api servers, 1 db server, to make graceful upgrade, minimize the service unavailable time during upgrade, we make make a workflow to

1. first upgrade db server db schema

2. then upgrade 1 api server

3. then upgrade 1 api server

4. then upgrade 2 web servers

5. then upgrade 1 webserver 2 mins later after the 2 web servers upgrade done.

#Get Started

##1. Install Required runtimes

This framework built by Java, use maven, jdk1.6 and maven is required.

##2. Download

git clone git@github.com:shensiduanxing/simpleworkflow.git

##3. Import to Eclipse

File -> Import -> Existing Maven Projects ->

##4. Examples

You can get started by run example unit test @ src/test/java/org/eason/workflowengine/WorkFlowServiceBasicTest.java

This example demos you an exmaple plugin that emulating upgrade workflow of an env composed of several VMs, you do not need to install database for this demo.

##5. Dev workflow Plugin

###5.1 Work Mechanism

1. TaskDispatcher

2. TaskExecutor

   can be internal and external, if external require to implement TaskDispatcher that can send task the external service.

3. TaskHandler

4. ForkJoinTask

5. ServiceTask

###5.2 Upgrade Env Emulator Plugin Example

demo Task dispatched to Internal TaskHandler. 

###5.3 Upgrade Env by External TaskExecutor Example

Plan:

1. Implement create workflow, tasks, sequenceflows

2. Implement execute workflow schedulely

1. get Runnable tasks
2. send runnable tasks to taskqueue

3. Implement dispatch app tasks to app task queue

4. Implement test use app worker to get task from app task queue and update task's status/events (put this test use app worker to simpleworkflow project)

Register App

Workflow Part: Create WorkFlow Done

Get WorkFlow Done

Create SequenceFlows Done

Delete Workflow Done

Execute WorkFlow Done

schedule execute Done

get runnable tasks Done

send runnable tasks to taskqueue Done

Dispatch tasks to app taskqueue Done

Implement from to tasks' interval Pending

Suspend WorkFlow Done

Resume WorkFlow Done

Cancel WorkFlow Done

Save WorkFlow Event Pending P2

Get App Workflows

Task Part: Create Tasks(Rest) Done

Execute WorkFlow Done get runnable tasks Done send runnable tasks to taskqueue Done Dispatch tasks to app taskqueue Done Implement from to tasks' interval Pending

Save Task Result Done

Task result will be saved in taskEvent done, failed event data

save by TaskEventService call TaskService to save the result, TaskEventService can choose to save the data or not

Set Task Timeout(Rest) 2 ways, one way by Workflow engine, one way by app worker report timeout task event

Get WorkFlow Tasks(Rest) Done

Get Tasks Result(Rest) (Workflow id, task name) Done

Set workflow Done when all tasks done On-going

Task Events Part:

Save Task Event | Update Task Status (Rest) Done

Get Task Events(Workflow id, task id) (Rest) Done

Get Workflow Task Events(Workflow id) (Rest) Done

1. Implement WorkFlowRepository to create Workflow entity

Workflow entity is able to get Tasks and SequenceFlows

2. Implement from to tasks' interval

3. Implement OAuth

4. System will keep appÕs latest 5000 workflows

5. System support 10K concurrent workflows execution

6. System can work normally when there are large

7. Implement app can only get itself's workflows and tasks

8. Implement multiple tasks groups' dependency