Running and modifying the employee roster starter application for Red Hat Business Optimizer using an IDE
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Abstract
Preface
As a business rules developer, you can use an IDE to build, run, and modify the employee-rostering
starter application that uses the Red Hat Business Optimizer functionality.
Prerequisites
- You use an integrated development environment, such as Eclipse (including Red Hat Developer Studio) or IntelliJ IDEA.
- You have an understanding of the Java language.
Chapter 1. Overview of the employee rostering starter application
The employee rostering starter application assigns employees to shifts on various positions in an organization. For example, you can use the application to distribute shifts in a hospital between nurses, guard duty shifts across a number of locations, or shifts on an assembly line between workers.
Optimal employee rostering must take a number of variables into account. For example, different skills can be required for shifts in different positions. Also, some employees might be unavailable for some time slots or might prefer a particular time slot. Moreover, an employee can have a contract that limits the number of hours that the employee can work in a single time period.
The Red Hat Business Optimizer rules for this starter application use both hard and soft constraints. During an optimization, the planning engine may not violate hard constraints, for example, if an employee is unavailable (out sick), or that an employee cannot work two spots in a single shift. The planning engine tries to adhere to soft constraints, such as an employee’s preference to not work a specific shift, but can violate them if the optimal solution requires it.
Chapter 2. Building and running the employee rostering starter application
You can build the employee rostering starter application from the source code and run it using a JBoss EAP or WildFly application server.
You can use the command line to build the application, then install it into a stand-alone server.
Alternatively, you can use your IDE, for example, Eclipse (including Red Hat JBoss Developer Studio), to build and run the application.
You can also deploy and run the pre-built WAR file that is supplied with the source code.
For information about using the application, see Deploying and using the employee roster starter application for Red Hat Business Optimizer on Red Hat OpenShift Container Platform.
2.1. Preparing deployment files
You must download and prepare the deployment files before building and deploying the application.
Procedure
-
Download the
rhpam-7.4.0-add-ons.zip
file from the Software Downloads page for Red Hat Process Automation Manager 7.4. - Unzip the downloaded archive.
Unzip the
rhpam-7.4.0-employee-rostering.zip
file that is extracted from the add-ons archive.The
employee-rostering-distribution-7.23.0.Final-redhat-00002
folder is created. This folder is the base folder in subsequent parts of this document.NoteFile and folder names might have higher version numbers than specifically noted in this document.
2.2. Building and running the employee rostering starter application from the command line
You can use the command line to build the employee rostering starter application and run it.
If you use this procedure, the data is stored in memory and is lost when the server is stopped. To build and run the application with a database server for persistent storage, see Section 2.3, “Building and running the employee rostering starter application with persistent data storage from the command line”.
Prerequisites
- You prepared the deployment files as described in Section 2.1, “Preparing deployment files”.
- A Java Development Kit is installed.
- Maven is installed.
- The host has access to the Internet. The build process uses the Internet for downloading Maven packages from external repositories.
Procedure
-
In a terminal window, change to the
sources
directory. Run the following command:
mvn clean install
- Wait for the build process to complete.
Use one of the following methods to run the application:
Run the WildFly server deployed as part of the build process:
-
In the
local/appserver/wildfly-14.0.1-final/standalone/deployments
subdirectory, create theoptaweb-employee-rostering-webapp-<version>.war.dodeploy
file. The<version>
must be the same as in the existingoptaweb-employee-rostering-webapp-<version>.war
symlink in the same directory. -
In the
local/appserver/wildfly-14.0.1-final/bin
subdirectory, run the./standalone.sh
command.
-
In the
-
Deploy the
optaweb-employee-rostering-webapp/target/optaweb-employee-rostering-*.war
file into an existing WildFly or JBoss EAP server and start the application server. Use the following commands to run a server using Maven:
mvn -N wildfly:start wildfly:deploy mvn gwt:codeserver
NoteIf you use Maven to start the server, the UI uses the gwt codeserver and monitors the gwtui source. In this case, if you change gwtui code, the codeserver picks the changes up automatically; there is no need to rebuild the application for gwtui code changes.
Later, to stop this server, use the command:
mvn -N wildfly:shutdown
- To access the application, enter http://localhost:8080/gwtui/gwtui.html in a web browser.
2.3. Building and running the employee rostering starter application with persistent data storage from the command line
If you use the command line to build the employee rostering starter application and run it, you can provide a database server for persistent data storage.
Prerequisites
- You prepared the deployment files as described in Section 2.1, “Preparing deployment files”.
- A Java Development Kit is installed.
- Maven is installed.
- The host has access to the Internet. The build process uses the Internet for downloading Maven packages from external repositories.
- You have a deployed WildFly or Red Hat JBoss EAP application server and a deployed MySQL or PostrgeSQL database server.
- You have set up a JDBC data source in the application server for the database server.
Procedure
-
In a terminal window, change to the
sources
directory. Run the following command:
mvn clean install -Dproductized -Dorg.optaweb.employeerostering.persistence.datasource=<dsname> -Dorg.optaweb.employeerostering.persistence.dialect=<dialect>
In the preceding command, replace the following values:
- <dsname> with the name of the data source in the application server.
<dialect> with one of the following strings, depending on the type of database server:
-
For MySQL,
org.hibernate.dialect.MySQL5Dialect
-
For PostgreSQL,
org.hibernate.dialect.PostgreSQLDialect
-
For MySQL,
- Wait for the build process to complete.
-
Deploy the
optaweb-employee-rostering-webapp/target/optaweb-employee-rostering-7.23.0.Final-redhat-00002.war
directory into the application server and start the application server. - To access the application, enter http://localhost:8080/gwtui/gwtui.html in a web browser.
2.4. Building and running the employee rostering starter application using Eclipse
You can use Eclipse, including Red Hat JBoss Development Studio, to build the employee rostering starter application and run it.
Prerequisites
- You prepared the deployment files as described in Section 2.1, “Preparing deployment files”.
- Eclipse is installed.
- The host has access to the Internet. The build process uses the Internet for downloading Maven packages from external repositories.
- Google Chrome is installed in order to run the application with the suggested configuration.
You can modify the configuration to use another web browser.
Procedure
- Start Eclipse.
- From the main menu, select File > Import….
- Select the Maven > Existing Maven projects wizard.
- For the root directory, select the root directory of the application source.
- Click Finish.
Optionally, to avoid seeing many errors in Eclipse:
-
In the root directory of the application source, run the
mvn clean install
command and wait for the build to finish. -
In the Eclipse navigation tree, right-click
employee-rostering-shared
and select Build Path > Configure Build Path…. - Click the Source tab, then click Add Folder….
-
Select the
employee-rostering-shared/target/generated-sources
folder and click OK.
-
In the root directory of the application source, run the
- From the main menu, select Run > External Tools > External Tools Configurations….
Under Program, create the following launch configurations:
Open OptaWeb Employee Rostering in Chrome:
-
Name:
Open OptaWeb Employee Rostering in Chrome
-
Location:
/usr/bin/google-chrome
-
Working Directory:
${workspace_loc:/employee-rostering}
Arguments:
--incognito http://localhost:8080/gwtui/gwtui.html
NoteYou can change the name, location. and arguments to use another browser instead of Chrome.
-
Name:
Kill Code Server:
-
Name:
Kill Code Server
-
Location:
/usr/sbin/fuser
-
Working Directory:
${workspace_loc:/employee-rostering}
-
Arguments:
fuser -k 9876/tcp
-
Name:
- From the main menu, select Run > Run Configurations….
Under Maven Build, create the following launch configurations:
OptaWeb Employee Rostering Build:
-
Name:
OptaWeb Employee Rostering Build
-
Base directory:
${workspace_loc:/employee-rostering}
-
Goals:
clean install
-
Parameter:
gwt:skipCompilation
Value:true
-
Name:
OptaWeb Employee Rostering Start Code Server:
-
Name:
OptaWeb Employee Rostering Start Code Server
-
Base directory:
${workspace_loc:/employee-rostering}
-
Goals:
gwt:codeserver
-
Parameter:
gwt:skipCompilation
Value:true
-
Name:
OptaWeb Employee Rostering Start Webserver:
-
Name:
OptaWeb Employee Rostering Start Webserver
-
Base directory:
${workspace_loc:/employee-rostering}
-
Goals:
wildfly:start wildfly:deploy
-
Parameter:
gwt:skipCompilation
Value:true
-
Name:
OptaWeb Employee Rostering Stop Webserver:
-
Name:
OptaWeb Employee Rostering Stop Webserver
-
Base directory:
${workspace_loc:/employee-rostering}
-
Goals:
wildfly:shutdown
-
Parameter:
gwt:skipCompilation
Value:true
-
Name:
Under Launch Group, create a launch group named
OptaWeb Employee Rostering Run
. Add the following launches to it:-
Program::Kill Code Server
Launch mode: inherit Post launch action: Wait until terminated -
Maven Build::OptaWeb Employee Rostering Stop Webserver
Launch mode: inherit Post launch action: Wait until terminated -
Maven Build::OptaWeb Employee Rostering Build
Launch mode: inherit Post launch action: Wait until terminated -
Maven Build::OptaWeb Employee Rostering Start Webserver
Launch mode: inherit Post launch action: none -
Maven Build::OptaWeb Employee Rostering Start Code server
Launch mode: inherit Post launch action: Wait for console output (regexp):The code server is ready at
-
Program::Open OptaWeb Employee Rostering in Chrome
Launch mode: inherit Post launch action: none
-
To build, run, and immediately acccess the application, run the
OptaWeb Employee Rostering Run
launch group. You can then change the application and rerun the launch group to test your changes.NoteWhen you use this method to run the application, the UI uses the gwt codeserver and monitors the gwtui source. If you change gwtui code, the codeserver picks the changes up automatically; there is no need to rebuild the application for gwtui code changes.
2.5. Running the supplied pre-built WAR file
To access the Employee Rostering starter application, you can deploy and run the pre-built employee-rostering-webapp-7.23.0.Final-redhat-00002.war
file that is supplied with Red Hat Process Automation Manager.
Prerequisites
- You prepared the deployment files as described in Section 2.1, “Preparing deployment files”.
- A Java Development Kit is installed.
- You have a deployed WildFly or Red Hat JBoss EAP application server.
Procedure
In your WildFly or Red Hat JBoss EAP application server, enable property replacement. For more information about enabling and disabling property replacement in Red Hat JBoss EAP, see Property Replacement.
- Start the application server in standalone mode.
Start the management CLI by entering the following command:
EAP_HOME/bin/jboss-cli.sh --connect
In the management CLI enter the following command:
/subsystem=ee:write-attribute(name="spec-descriptor-property-replacement",value=true)
- Stop the application server.
-
Deploy the
binaries/employee-rostering-webapp-7.23.0.Final-redhat-00002.war
directory into the application server and start the application server. - To access the application, enter http://localhost:8080/gwtui/gwtui.html in a web browser.
Chapter 3. Overview of the source code of the employee rostering starter application
The employee rostering starter application consists of the following principal components:
- The server that implements the rostering logic using Red Hat Business Optimizer and provides a REST API.
-
The client that implements a user interface using the
gwt
library and calls the server using the REST API.
While some code is shared between the client and the server, you can build and use these components independently. In particular, you can implement a different user interface and use the REST API to call the server.
In addition to the two main components, the employee rostering template contains a generator of random source data (useful for demonstration and testing purposes) and a benchmarking application.
Modules and key classes
The Java source code of the employee rostering template contains several Maven modules. Each of these modules includes a separate Maven project file (pom.xml
), but they are intended for building in a common project.
The modules contain a number of files, including Java classes. This document lists all the modules, as well as the classes and other files that contain the key information for the employee rostering calculations.
-
employee-rostering-benchmark
module: Contains an additional application that generates random data and benchmarks the solution. -
employee-rostering-distribution
module: Contains readme files. -
employee-rostering-docs
module: Contains documentation files. -
employee-rostering-gwtui
module: Contains the client application with the user interface, developed using thegwt
toolkit. employee-rostering-server
module: Contains the server application that uses Red Hat Business Optimizer to perform the rostering calculation.-
src/main/resources/org/optaweb/employeerostering/server/solver/employeeRosteringScoreRules.drl
file: Contains the rules for the Red Hat Business Optimizer calculation. These rules are written in the Drools rules language. You can modify the rules to change the logic for employee rostering. -
src/main/java/org.optaweb.employeerostering.server.roster/rosterGenerator.java
class: generates random input data for demonstration and testing purposes. If you change the requires input data, change the generator accordingly.
-
employee-rostering-shared
module: Contains the data structures shared between the server and client applications. In particular, undersrc/main/java/org/optaweb/employeerostering/shared/*
, this module includes the Java classes that define the input data for the rostering calculations, including the following classes:-
employee/EmployeeAvailability.java
defines availability information for an employee. For every time slot, an employee can be unavailable, available, or it can be a preferred timeslot for the employee. -
employee/Employee.java
defines an employee. An employee has a name, a list of skills, and works under a contract. Skills are represented byEmployeeSkillProficiency
objects. -
roster/Roster.java
defines the calculated rostering information. -
shift/Shift.java
defines a shift to which an employee can be assigned. A shift is defined by a time slot and a spot. For example, in a diner there could be a shift in theKitchen
spot for theFebruary 20 8AM-4PM
time slot. Multiple shifts can be defined for a given spot and time slot; in this case, multiple employees are required for this spot and time slot. -
skill/Skill.java
defines a skill that an employee can have. -
spot/Spot.java
defines a spot where employees can be placed. For example, in a dinerKitchen
can be a spot. -
contract/Contract.java
defines a contract that sets the limits of work time for an employee in various time periods. tenant/Tenant.java
defines a tenant. Each tenant represents an independent set of data; any change in the data for one tenant does not affect any other tenants.The
employee-rostering-shared
module also includes other shared artifacts:-
*View.java
classes define value sets that are calculated from other information; the client application can read these values through the REST API, but not write them. -
*RestService.java
interfaces define the REST API. Both the server and the client application separately define implementations of these interfaces.
-
-
employee-rostering-shared-gwt
module: Contains some of the classes required for the GWT client application. -
employee-rostering-webapp
module: Contains the HTML and other files necessary for building the entire application (client and server).
Chapter 4. Modifying the employee rostering starter application
To modify the employee rostering starter application to suit your needs, you must change the rules that govern the optimization process. You must also ensure that the data structures include the required data and provide the required calculations for the rules. If the required data is not present in the user interface, you must also modify the user interface.
The following procedure outlines the general approach to modifying the employee rostering starter application.
Prerequisites
- You have a build environment that successfully builds the application.
- You can read and modify Java code.
Procedure
Plan the required changes. Answer the following questions:
- What are the additional scenarios that must be avoided? These scenarios are hard constraints.
- What are the additional scenarios that the optimizer must try to avoid when possible? These scenarios are soft constraints.
- What data is required to calculate if each scenario is happening in a potential solution?
- Which of the data can be derived from the information that the user enters in the existing version?
- Which of the data can be hardcoded?
- Which of the data must be entered by the user and is not entered in the current version?
- If any required data can be calculated from the current data or can be hardcoded, add the calculations or hardcoding to existing view or utility classes. If the data must be calculated on the server side, add REST API endpoints to read it.
-
If any required data must be entered by the user, add the data to the classes representing the data entities (for example, the
Employee
class), add REST API endpoints to read and write the data, and modify the user interface to enter the data. When all the data is available, modify the rules. For most modifications, you must add a new rule. The rules are located in the
src/main/resources/org/optaweb/employeerostering/server/solver/employeeRosteringScoreRules.drl
file of theemployee-rostering-server
module.Use the Drools language for the rules. For reference information about the Drools rule language, see Rule Language Reference. Classes defined in the
optaweb-employee-rostering-shared
andoptaweb-employee-rostering-server
modules are available to the decision engine.- After modifying the application, build and run it.
Appendix A. Versioning information
Documentation last updated on Friday, May 22, 2020.