cc-metric-collector/sinks

This folder contains the sinks for the cc-metric-collector.

metricSink.go

The base class/configuration is located in metricSink.go.

Sinks

• stdoutSink.go: Writes all metrics to stdout in InfluxDB line protocol. The sink does not use https://github.com/influxdata/line-protocol to reduce the executed code for debugging
• influxSink.go: Writes all metrics to an InfluxDB database instance using a blocking writer. It uses https://github.com/influxdata/influxdb-client-go . Configuration for the server, port, user, password and database name are in the global configuration file
• natsSink.go: Sends all metrics to an NATS server using the InfluxDB line protocol as encoding. It uses https://github.com/nats-io/nats.go . Configuration for the server, port, user, password and database name are in the global configuration file. The database name is used as subject for the NATS messages.
• sqliteSink.go: Writes all metrics to a Sqlite3 database. It uses https://github.com/mattn/go-sqlite3

Installation

Nothing to do, all sinks are pure Go code

Contributing own sinks

A sink contains three functions and is derived from the type Sink (in metricSink.go):

• Init(config SinkConfig) error
• Write(measurement string, tags map[string]string, fields map[string]interface{}, t time.Time) error
• Close()

The data structures should be set up in Init() like opening a file or server connection. The Write() function takes a measurement, tags, fields and a timestamp and writes/sends the data. The Close() function should tear down anything created in Init().

Finally, the sink needs to be registered in the metric-collector.go. There is a list of sinks called Sinks which is a map (string -> pointer to sink). Add a new entry with a descriptive name and the new sink.