Navigate through simulations.

Managing Simulations

To access the Simulations section, click on Simulations in the navbar.

The Simulations view contains all the simulations you have configured and the result of their last run.

Simulation table

If you don’t have any simulations configured yet and don’t know how to start, you can download some FrontLine pre-configured projects by clicking on the “Download sample simulations” green button.


Those samples are ready to use maven, sbt and gradle projects with proper configuration for FrontLine. You can also download those samples with the download link in the Documentation section.

Back to the Simulations section, at the top, there is an action bar which allow several actions:

  • Create a simulation
  • Search by simulation or team name
  • Edit global properties
  • Delete selected simulations
Action bar

Global Properties

Global properties contains every JVM options and system properties used by all of your simulations by default. Editing those properties will be propagated to all the simulations.

If you don’t want to use the default properties, check Use custom global properties and enter your own.


If you want specific properties for a simulation, you will be allowed to ignore those properties by checking the Override Global Properties box when creating or editing the simulation:


Creating a simulation

In order to create a simulation click on the “Create” button in the simulations table. There are 6 steps to create a simulation, 3 of which are optional.

Step 1: General

Create simulation - Step 1
  • Name: the name that will appear on the simulations table.
  • Team: the team which owns the simulation.
  • Class name: the package and the name of your simulation scala class in the project that you want to start.

Step 2: Build configuration

In this step, you’ll configure the artifact of the Simulation to execute.

Create simulation - Step 2

Step 3: Pools configuration

In this step, you’ll configure the pools used for the FrontLine injectors.

FrontLine private beta pools are available in the following regions:

  • Europe (Paris)
  • US East (N. Virginia)
  • US West (N. California)
Create simulation - Step 3
  • Weight distribution: on even, every injector will produce the same load. On custom, you have to set the weight in % of each pool (eg the first pool does 20% of the requests, and the second does 80%). The sum of the weight should be 100%.
  • Pools: defines the pools to be used when initiating the FrontLine injectors.

You can add many pools with a different number of hosts to run your simulation.

After this step, you can save the simulation, or click on More options to access optional configuration.

Step 4 & 5: JVM options & Java System Properties

These steps allows you to defines JVM arguments and system properties used when running this particular simulation. You can choose to override the global properties.

Create simulation - Step 4
Create simulation - Step 5

Step 6: Time window

Configuring a ramp up or ramp down means that the start and end of your simulation won’t be used for calculating metrics and assertions.

Create simulation - Step 6
  • Ramp Up: the number of seconds you want to exclude at the beginning of the run.
  • Ramp Down: the number of seconds you want to exclude at the end of the run.

Simulations table

Now that you have created a simulation, you can start it by clicking on the icon in the Start column of the table.


A run have the following life cycle:

  • Building: in which it will download the simulation artifact and prepare the hosts
  • Deploying: in which it will deploy the simulation to run on all the hosts
  • Injecting: in which the simulation is running and viewable from the Reports

By clicking on the icon in the Build Start column, Frontline will display the build logs of the simulation. There is a limit of 1000 logs for a run.


You can click on the icon next to the status (if there is one) to display the assertions of the run. Assertions are the assumptions made at the beginning of the simulation to be verified at the end:


Useful tips

  • You can edit the simulation by clicking on the icon next to his name
  • You can search a simulation by his name, or its team name
  • You can sort the simulations by any column except the Start one
  • A Delete button will appear on the action bar when you select a simulation, you will be able to delete all the selected simulations
  • When a simulation is running, you can abort the run by clicking on the Abort button
  • You can copy a simulation ID by clicking on the icon next to his name

Be aware that deleting a simulation will delete all the associated runs.

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