# Class SingleServerServiceRunner

OptimaJet.Workflow.Core.Runtime.ServiceRunners.SingleServerServiceRunner

Provides a service runner implementation for single-server workflow runtime execution.

Namespace: [OptimaJet.Workflow.Core.Runtime.ServiceRunners](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.ServiceRunners/)

```csharp
public class SingleServerServiceRunner : IWorkflowServiceRunner
```

## Type Hierarchy

-   SingleServerServiceRunner Current type
    -   Implemented interfaces
        -   [IWorkflowServiceRunner](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.ServiceRunners/IWorkflowServiceRunner/)

## Constructors

`public SingleServerServiceRunner(WorkflowRuntime runtime, SingleServerSettings singleServerSettings)` 

Initializes a new instance of the [SingleServerServiceRunner](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.ServiceRunners/SingleServerServiceRunner/) class using in-memory single-server settings.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `runtime` | `WorkflowRuntime` | The workflow runtime associated with this runner. |
| `singleServerSettings` | `SingleServerSettings` | The settings used to initialize an in-memory single-server settings source. |

`public SingleServerServiceRunner(WorkflowRuntime runtime, ISingleServerSettingsSource settingSource)` 

Initializes a new instance of the [SingleServerServiceRunner](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.ServiceRunners/SingleServerServiceRunner/) class.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `runtime` | `WorkflowRuntime` | The workflow runtime associated with this runner. |
| `settingSource` | `ISingleServerSettingsSource` | The settings source used to load and save single-server settings. |

## Properties

`public bool IsSupportsMultiServer { get; }` 

Gets a value indicating that this runner is configured for single-server execution.

## Methods

`public Task StartAsync(ITimerManager manager)` 

Starts single-server initialization, synchronizing runtime status and restoring active processes when configured to do so.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `manager` | `ITimerManager` | The timer manager to start after startup, if provided and runtime is not cold. |

### Returns

| Type | Description |
| --- | --- |
| `Task` | A task that completes when startup initialization has finished. |

### Exceptions

| Type | Description |
| --- | --- |
| `InvalidOperationException` | Thrown when multi-server runtimes already exist in the same persistence storage. |

### Remarks

The method checks for incompatible multi-server runtimes in the same persistence storage, ensures the workflow runtime status is [RuntimeStatus.Single](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Model/RuntimeStatus/), and optionally restores running processes before starting the timer manager.

[Previous SingleServerRestorer](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.ServiceRunners/SingleServerRestorer/) [Next DefaultMultiServerSettingsSource](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Settings/DefaultMultiServerSettingsSource/)