# Hercules log

**Location**: [Hercules](https://vostok.gitbook.io/logging/modules/hercules) module.

```csharp
var herculesLog = new HerculesLog(new HerculesLogSettings(herculesSink, logStreamName));
var dynamicallyConfiguredLog = new HerculesLog(() => ObtainSettings());
```

`HerculesLog` converts incoming [log events](https://vostok.gitbook.io/logging/concepts/log-events) to [Hercules events](https://github.com/vostok/hercules/tree/master/hercules-protocol) according to [Hercules log event schema](https://github.com/vostok/hercules/blob/master/doc/event-schema/log-event-schema.md) and then sends resulting events with an instance of [IHerculesSink](https://github.com/vostok/hercules.client.abstractions/blob/master/Vostok.Hercules.Client.Abstractions/IHerculesSink.cs). Additional details on events mapping can be found in module's [description on GitHub](https://github.com/vostok/logging.hercules).

## Configuration

`HerculesLog` is configured with `HerculesLogSettings`, having 2 mandatory parameters:

| Option         | Description                                    |
| -------------- | ---------------------------------------------- |
| `HerculesSink` | An instance of sink to send events with.       |
| `Stream`       | Name of the Hercules stream to send events to. |

Ensure that provided sink instance is configured with an API key with sufficient permissions to write into selected stream.

## Usage tips

* Prefer to use a singleton instance of `IHerculesSink` everywhere in the application, including `HerculesLog`. Sink instances involve background tasks and are therefore quite expensive.
* Reporting of lost of log events generally depends on the nature of `IHerculesSink` implementation. Default implementation in [vostok.hercules.client](https://github.com/vostok/hercules.client) repository provides a set of counters for these purposes.