Document updated on Sep 15, 2019

Sending out logs, metrics, and traces

The Opencensus exporter is a single component that allows you to export data to multiple providers, both open source and privative.

You will be interested in Opencensus when you want to see data in one of its supported exporters. For instance, you might want to send metrics to Prometheus. That would be as easy as adding this snippet in the root level of your krakend.json file:

{
    "version": 3,
    "extra_config": {
        "telemetry/opencensus": {
            "exporters": {
                "prometheus": {
                    "port": 9091,
                    "namespace": "krakend"
                }
            }
        }
    }
}

Configuration

The Opencensus needs at least an exporter to work, although multiple exporters can be added in the same configuration. Notice that adding several exporters that push metrics out to multiple systems will affect the performance of the server.

Every exporter has its own configuration and it’s described in its section.

By default, all exporters sample the 100% of the requests received every second, but this can be changed by specifying more configuration:

{
    "version": 3,
    "extra_config": {
        "telemetry/opencensus": {
            "sample_rate": 100,
            "reporting_period": 1,
            "enabled_layers": {
                "backend": true,
                "router": true,
                "pipe": true
            },
            "exporters": {
                "prometheus": {
                    "port": 9091
                }
            }
        }
    }
}

• sample_rate is the percentage of sampled requests. A value of 100 means that all requests are exported (100%). If you are processing a huge amount of traffic you might want to sample only a part of what’s going on.
• reporting_period is the number of seconds passing between reports
• exporters is a key-value with all the exporters you want to use. See each exporter configuration for the underlying keys.
• enabled_layers let you specify what data you want to export. All layers are enabled by default:
  • Use backend to report the activity between KrakenD and your services
  • Use router to report the activity between end-users and KrakenD
  • Use pipe to report the activity at the beginning of the proxy layer. It gives a more detailed view of the internals of the pipe between end-users and KrakenD.