> For the complete documentation index, see [llms.txt](https://docs.redefine.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.redefine.dev/configuration/parallel-test-execution/remote-workers/delayed-workers-and-reruns.md).

# Delayed Workers and Reruns

The startup time of CI machines may experience delays due to the unavailability of machines or infrastructure issues. The worker that has been delayed will have a considerably shorter effective [Broken mention](broken://pages/ukeQo52y77NM3cuhDJos) compared to other workers. Consequently, there is a risk of important tests being missed.

Repeating the execution of a single worker can yield similar results.

### Worker Identifier

To address the issue of delays and potential missed tests due to CI machine unavailability or infrastructure issues, you can utilize the `worker_id` optional parameter.

To implement this solution, use the following command:

{% tabs %}
{% tab title="Pytest" %}

```bash
redefine install --pytest --worker --worker-id=$WORKER_ID
```

{% endtab %}

{% tab title="Cypress" %}

```bash
redefine install --cypress --worker --worker-id=$WORKER_ID
```

{% endtab %}

{% tab title="Mocha" %}

```bash
redefine install --mocha --worker --worker-id=$WORKER_ID
```

{% endtab %}
{% endtabs %}

Ensure that the `WORKER_ID` environment variable contains the worker identifier specific to your CI system.

#### Handling worker rerun

it's important to note that if you have repeated executions of a single worker without re-running the orchestrator, the effective time limit for each subsequent execution may be reduced to zero. To prevent this, you can include the rerun attempt as part of the `worker_id`. 

Here's an example:

{% tabs %}
{% tab title="Pytest" %}

```bash
redefine install --pytest --worker --worker-id="${WORKER_ID}_${ATTEMPT}"
```

{% endtab %}

{% tab title="Cypress" %}

```bash
redefine install --cypress --worker --worker-id="${WORKER_ID}_${ATTEMPT}"
```

{% endtab %}

{% tab title="Mocha" %}

```bash
redefine install --mocha --worker --worker-id="${WORKER_ID}_${ATTEMPT}"
```

{% endtab %}
{% endtabs %}

In this case, make sure to set the `ATTEMPT` environment variable to the rerun attempt counter. This approach guarantees that each attempt is assigned a unique identifier, avoiding a zero effective time limit for repeated executions.

By implementing these strategies, you can mitigate delays, manage worker execution, and minimize the risk of missing important tests in your CI workflow.