Flowable MongoDB

More information about Flowable: see http://www.flowable.org/ and https://github.com/flowable/flowable-engine

This repository contains the source code for using MongoDB as a persistent data store for the Flowable process engine (support for the other engines (CMMN/DMN) are not yet implemented).

It is currently considered in alpha state as not all features have been implemented. Once the default test suite runs fully against this implementation, it will be deemed stable.

Requirements

• MongoDB 4.0+
• Flowable 6.4.0+

Usage

Add the flowable-process-engine-mongodb and flowable-engine dependency to your Maven pom.xml (or a similar operation when not using Maven).

<dependency>
    <groupId>org.flowable</groupId>
    <artifactId>flowable-engine</artifactId>
    <version>6.4.0</version>
</dependency>
<dependency>
    <groupId>org.flowable</groupId>
    <artifactId>flowable-process-engine-mongodb</artifactId>
    <version>6.4.0.alpha1</version>
</dependency>

Create a ProcessEngine instance as follows (changing the server url as needed):

ProcessEngine processEngine = new MongoDbProcessEngineConfiguration()
    .setServerAddresses(Arrays.asList(new ServerAddress("localhost", 27017)))
    .setDisableIdmEngine(true)
    .buildProcessEngine();

Development

Single server

To set up a local MongoDB server that can be used to execute the unit tests against:

(Following instructions have been tested on OS X only. PR's for other systems appreciated!)

• Download the latest MongoDB community server from https://www.mongodb.com/download-center#community
• Unzip and create a folder data in the unzipped folder
• Start MongoDB as follows through the terminal

ulimit -n 4096
./mongod --port 27017 --bind_ip_all --dbpath ../data/ --replSet rs0

• Now execute ./mongo from the bin folder
• In this shell, execute

rs.initiate()

Notes:

• The ulimit is needed or otherwise executing the unit tests quickly leads to the 'too many open files' exception.
• Transactions are currently supported on replicasets only, hence the use of the replSet parameter.

Multiple servers

To set up a cluster of MongoDB servers that share the same replicaset and that can be used to execute the unit tests against:

• Download the latest MongoDB community server from https://www.mongodb.com/download-center#community

• Unzip and create data1, data2 and data3 folders in the unzipped folder

• Start the MongoDB instances as follows through separate terminal windows

ulimit -n 4096
./mongod --port 27017 --bind_ip_all --dbpath ../data1/ --replSet rs0

ulimit -n 4096
./mongod --port 27018 --bind_ip_all --dbpath ../data2/ --replSet rs0 

ulimit -n 4096
./mongod --port 27019 --bind_ip_all --dbpath ../data3/ --replSet rs0

• Now execute ./mongo from the bin folder
• In this shell, execute

rsconf = {_id: "rs0", members: [ {_id: 0, host: "localhost:27017"}, {_id: 1,host: "localhost:27018"}, {_id: 2,host: "localhost:27019"}]}

rs.initiate(rsconf)