> OctoPerf load testing - Launching a Runtime Scenario documentation page. How to use the runtime scenario launcher wizard?

Source: https://api.octoperf.com/doc/runtime/edit-scenario/launch-test/

# Launching a test

To launch a test, click on the **Review & Launch** button from the [execution scenario page](https://api.octoperf.com/doc/runtime/edit-scenario/). The launch test wizard appears. It has three steps: **Check Design**, **Check Runtime** and **Launch test**. The first two check the scenario before it runs, so that you do not consume credits on a test that would fail.

## Check Design {#check-design}

![Check Design](https://api.octoperf.com/doc/runtime/edit-scenario/img/launch-check-vus.png "Check Design")

The first step runs the [sanity check](https://api.octoperf.com/doc/design/edit-virtual-user/validation/#sanity-check) of each Virtual User of the scenario, including the [Set Up and Tear Down](https://api.octoperf.com/doc/runtime/edit-scenario/edit-user-profile/options/setup-teardown/) Virtual Users. This step validates that none of your Virtual Users contains critical errors. Such errors, like a missing CSV variable file, would prevent the test from running. You need to fix them before continuing to the next step.

The **Used By** column sums up the user profiles that run each Virtual User, by role: for example *User Journey*, when a single user profile runs it, or **Set Up** · 6 User Profiles. Click its header to sort the Virtual Users by it.

The **More** menu of a row opens the user profiles of the Virtual User:

- **Open User Profile**, when a single user profile runs it,
- **Show User Profiles**, when several do: the **Used By** dialog lists them, with the role the Virtual User plays in each (Virtual User, Set Up or Tear Down). Click one to open it.

!!! tip
    You can click on **Open Virtual User** to open this Virtual User and [proceed to a validation](https://api.octoperf.com/doc/design/edit-virtual-user/validation/) in order to see the list of sanity check messages.

## Check Runtime {#check-runtime}

![Check Runtime](https://api.octoperf.com/doc/runtime/edit-scenario/img/launch-check-runtime.png "Check Runtime")

The second step checks what the test needs to run. It has two blocks.

### Scenario

The **Scenario** block lists the problems found by the [scenario check](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/): a missing provider, a location with no agent, a load that never ends, a server the load generators cannot reach... Each row shows:

- The **Severity**: Error, Warning or Info,
- The **User Profile** to fix, empty for a problem that concerns the whole scenario,
- The **Message**, as a short title.

Click a row, or its **Inspect** button, to open a dialog that explains the problem and lists its fixes. **Previous** and **Next** go through the other problems. The button right of **Close** opens the page where the problem is fixed, or a **Fix it** menu when there are several.

Each problem is explained step by step on the [Scenario Check](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/) page.

!!! info
    For on-premise providers, the check places the load generators on the agents the way a test does. It reports a location with no agent up, agents too small or too few for the load, and agents busy with other tests. See [Agents and capacity](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/#agents-and-capacity).

### Monitors

If you configured [monitoring connections](https://api.octoperf.com/doc/monitoring/), OctoPerf automatically checks every enabled connection before launching the test. The **Type** column shows the kind of each connection, and the **Status** column the result of its check. When a connection fails, the **Reason** column says why. A connection that does not answer fails after 30 seconds.

Click a row, or its **Refresh** button, to check that connection again.

Before starting the test, you need to either:

- Fix any connectivity issue,
- Disable the invalid monitoring connections.

!!! tip
    Use the **More** menu of a row to open the Monitoring Connection, or to enable or disable it.

### What blocks the launch

- An **Error** of the scenario check blocks the launch, including [No subscription can run this scenario](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/#subscription-missing),
- An enabled monitoring connection that fails blocks the launch,
- **Warnings** and **Infos** never block the launch.

## Start test {#start-test}

### Launch test

The final step allows to select:

* The report name,
* The report template (only visible if at least one template is available),
* The subscription to use, among the ones that can run the scenario.

!!! tip
    Leave the Template field blank to use the default one.
    You can also [switch to an other template](https://api.octoperf.com/doc/analysis/edit-bench-report/templates/) while the test is running or completed.

![Subscription selection](https://api.octoperf.com/doc/runtime/edit-scenario/img/launch-check-subscription.png "Subscription selection")

Click on the _Launch Test_ button, the test startup procedure is shown within seconds. Please allow up to a few minutes for the [test to start](https://api.octoperf.com/doc/analysis/edit-bench-report/).

### Summary of the previous steps

![Launch blocked](https://api.octoperf.com/doc/runtime/edit-scenario/img/launch-test-summary.png "Launch blocked")

When a previous step blocks, is still running or reported warnings, a banner at the top of the **Launch test** step sums it up. Its title gives the verdict:

| Title | Meaning |
|-------|---------|
| **Launch blocked** | A step has errors: the test cannot be launched until they are fixed. |
| **Checks in progress** | A check is still running: the test can be launched once it finishes. |
| **Launch at your own risk** | The steps reported warnings: you can launch the test, but launching it means accepting them. |

The banner has one line per step concerned, for example *Check Runtime has blocking errors.*, with a link to open that step.

Key points to remember:

- **Check Design**: sanity check errors (Error level) are blocking.
- **Check Runtime**: scenario check errors are blocking, and all enabled monitors must be functional.

!!! info
    A scenario with an Error never starts, wherever it is launched from: the REST API, the Maven plugin, the CI integrations, JIRA, the scheduler and the MCP server refuse it as well. See [Scenario Check](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/#severities).

### Test starting

![test-launching](https://api.octoperf.com/doc/runtime/edit-scenario/img/test-launching.png)

Once all your load generators are green, the tests will start shortly. You can see more details through the **Show logs** button on top.

### No subscription found

When none of your subscriptions can run the scenario, the **Launch test** step shows no **Subscription** block, and its banner says that **Check Runtime has blocking errors**. The **Scenario** block of the Check Runtime step reports [No subscription can run this scenario](https://api.octoperf.com/doc/runtime/edit-scenario/scenario-check/#subscription-missing), with what stops each subscription: too many Virtual Users, a test too long, too many user profiles...

You can either lower the setting that is too high (load, duration or number of user profiles), or get a subscription that fits, from **Subscriptions** in the user menu.