writing-workload-generators.md

layout: page title: "Writing Workload Generators with CloudSim Express" permalink: /examples/writing-workload-generators

Writing Workload Generators with CloudSim Express

CloudSim Express introduces a new approach to connect workloads. In research, the workloads are available as traces, and they can be submitted all-at-once, or dynamically. To cater these requirements, CloudSim Express introduces two new interfaces,

• CloudSimWorkloadGenerator
• CloudSimTimeSeriesWorkloadGenerator

By default, an implementation of CloudSimWorkloadGenerator is available with the class, DummyWorkloadGenerator.

In this example, we are extending this DummyWorkloadGenerator to write a custom workload generator and deploy it with the system model that we built with Say "Hello World!" with CloudSim Express example.

Creating a java project for the workload generator

We implement the workload generator in a separate java project first. We use Maven-based java project.

1. Create a simple Maven project.
   1. Go to a new folder.
   2. Execute mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-simple -DarchetypeVersion=1.4
      • Pre-requisite: Maven
   3. Enter followings when prompted.
      1. groupId = org.cloudbus.cloudsim.express.examples
      2. artifactId = custom-workload-generator
      3. version = 1.0-SNAPSHOT
      4. package = org.cloudbus.cloudsim.express.examples
      5. Press Enter to confirm.
2. Configure dependencies.
   1. Go to the custom-workload-generator project folder.
   2. Open pom.xml
   3. Within the <dependencies> tag, copy the following to declare CloudSim Express as a dependency
      • Pre-requisite: You must build cloudsim-express project at least once.
      • Copy and paste the following.

        <dependency>
            <artifactId>cloudsim-express-extensions</artifactId>
            <groupId>org.cloudbus.cloudsim.cloudsim-express</groupId>
            <version>0.1-SNAPSHOT</version>
        </dependency> 
        

   4. Create the custom workload generator class in the /src/main/java/org/cloudbus/cloudsim/express/examples/ folder by creating a new file CustomWorkloadGenerator.java.
      • Delete the generated App.java file.
   5. Implement the workload generator to return a single cloudlet.
      • The sample code is available in the custom-workload-generator project.
   6. Build the project by executing mvn clean install from the project root directory (i.e., where the pom.xml file resides).

Deploying the custom workload generator

1. Copy the workload generator jar file from <custom-workload-generator>/target/custom-workload-generator-1.0-SNAPSHOT.jar, to cloudsim-express-tool-location/extensions.
2. Modify the system-model.yaml to use the custom workload generator.
   • From:

     ...
     Zone: &Zone
     name: "default zone"
     datacenter: *Datacenter
     broker:
      variant:
         className: "org.cloudbus.cloudsim.DatacenterBroker"
      name: "RegionalBroker"
     workloadGenerator:
      variant:
        className: "org.crunchycookie.research.distributed.computing.cloudsim.workload.impl.DummyWorkloadGenerator"   
     ...
     

   • To:

     ...
     Zone: &Zone
     name: "default zone"
     datacenter: *Datacenter
     broker:
      variant:
         className: "org.cloudbus.cloudsim.DatacenterBroker"
      name: "RegionalBroker"
     workloadGenerator:
      variant:
        className: "org.cloudbus.cloudsim.express.examples.CustomWorkloadGenerator"   
     ...
     

3. Executes the simulation via sh ./cloudsim-express.sh
4. Check the latest CloudSim log file from logs. You can observe that only one Cloudlet has been created during the simulation.

   ...
   0.01: RegionalBroker: VM #1 has been created in Datacenter #3, Host #1
   0.01: RegionalBroker: Sending cloudlet 1 to VM #1
   10000.01: RegionalBroker: Cloudlet 1 received
   10000.01: RegionalBroker: All Cloudlets executed. Finishing...
   10000.01: RegionalBroker: Destroying VM #1
   RegionalBroker is shutting down...
   ...
   

Materials

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The related materials are included in the resources folder.