Sending logs to the OpenTelemetry Collector is essential for centralizing and analyzing log data. Fortunately, you have several methods to do this, depending on your needs. In the following sections, we’ll explore different ways to send logs to the Collector.
File-Based Collection
For legacy applications that can’t use an SDK or logging library, you can configure the app to write logs to files. The OpenTelemetry Collector will then collect these logs by monitoring the directory.
To collect the logs, use the filelog receiver, which watches for new log files and reads them automatically. This method is especially useful for systems that are difficult to change but still need log collection.
Steps:
- First, configure your app to write logs to files.
- Then, set up the filelog receiver to monitor the directory.
- Finally, the Collector will read and process the logs.
Log Forwarder Collection
If you want more control over log processing, you can use a log forwarder like Fluentd or FluentBit. These tools collect logs from your apps, perform preprocessing tasks (such as filtering or parsing), and then forward the logs to the OpenTelemetry Collector.
To make this work, the fluentforward receiver in the Collector receives logs sent via the Fluentd Forward Protocol. As a result, this method gives you flexibility in routing and processing logs.
Steps:
- First, set up a log forwarder (Fluentd or FluentBit).
- Next, configure the forwarder to collect logs from your apps.
- Finally, the forwarder sends the logs to the Collector.
Direct Log Sending to the Collector
Alternatively, you can configure your app to send logs directly to the OpenTelemetry Collector using gRPC or HTTP. To do this, you will need to integrate an OpenTelemetry SDK or a logging library into your application.
Once configured, the app will send logs directly to the Collector. The OTLP receiver will then process the logs using the OpenTelemetry Protocol.
Steps:
- First, integrate the OpenTelemetry SDK or logging library into your app.
- Next, configure the app to send logs over gRPC or HTTP.
- Finally, the Collector will receive and process the logs using the OTLP receiver.
