InfluxDB reporter for Telemetry

Telemetry reporter for InfluxDB compatible events.

To use it, start the reporter with the start_link/1 function, providing it a list of Telemetry event names:

    TelemetryInfluxDB.start_link(
      events: [
        %{name: [:memory, :usage], metadata_tag_keys: [:host, :ip_address]},
        %{name: [:http, :request]},
      ]
    )

or put it under a supervisor:

children = [
  {TelemetryInfluxDB, [
    events: [
      %{name: [:memory, :usage], metadata_tag_keys: [:host, :ip_address]},
      %{name: [:http, :request]}
  ]}
]

Supervisor.start_link(children, ...)

By default the reporter sends events through UDP to localhost:8089.

Note that the reporter doesn't aggregate events in-process by default - it sends updates to InfluxDB whenever a relevant Telemetry event is emitted. See the :batch_size option below to configure this behavior.

Running the tests currently requires jq. Please make sure you have it installed before running the tests.

$ make test

It should setup the latest InfluxDB in docker for both v1 and v2 and runs all the tests against them.

Possible options for the reporter:

• :version - :v1 or :v2. The version of InfluxDB to use; defaults to :v1 if not provided
• :reporter_name - unique name for the reporter. The purpose is to distinguish between different reporters running in the system. One can run separate independent InfluxDB reporters, with different configurations and goals.
• :protocol - :udp or :http. Which protocol to use for connecting to InfluxDB. Default option is :udp. InfluxDB v2 only supports :http for now.
• :host - host, where InfluxDB is running.
• :port - port, where InfluxDB is running.
• :events - list of Telemetry events' names that we want to send to InfluxDB. Each event should be specified by the map with the field name, e.g. %{name: [:sample, :event, :name]}. Event names should be compatible with Telemetry events' format. It is also possible to specify an optional list of metadata keys that will be included in the event body and sent to InfluxDB as tags. The list of metadata keys should be specified in the event data with the field metadata_tag_keys, e.g. %{name: [:sample, :event, :name], metadata_tag_keys: [:sample_meta, sample_meta2]}
• :batch_size - the maximum number of events to send to InfluxDB at one time. (default 1)
• :tags - list of global static tags, that will be attached to each reported event. The format is a map, where the key and the value are tag's name and value, respectively. Both the tag's name and the value could be atoms or binaries.

• :db - name of the location where time series data is stored in InfluxDB v1
• :username - username of InfluxDB's user that has writes privileges. Only required in v1.
• :password - password for the user. Only required for v1.

• :bucket - name of the location where time series data is stored in InfluxDB v2
• :org - workspace in InfluxDB v2 where a bucket belongs
• :token - InfluxDB v2 authentication token used for authenticating requests. Must have write privileges to the bucket and org specified.

For the HTTP protocol, worker_pool is used for sending requests asynchronously. Therefore the HTTP requests are sent in the context of the separate workers' pool, which does not block the client's application (it is not sent in the critical path of the client's process).

On the other hand, UDP packets are sent in the context of the processes that execute the events. However, the lightweight nature of UDP should not cause any bottlenecks in such a solution.

Events are sent straightaway without any batching techniques by default. If the :batch_size option is set to a value higher than 1, all events received since the previous batch will be sent in the next batch (up to a maximum of :batch_size events).

Once the reporter is started, it is attached to specified Telemetry events. The events are detached when the reporter is shutdown.

TelemetryInfluxDB is copyright (c) 2019 Ludwik Bukowski.

TelemetryInfluxDB source code is released under MIT license.

See LICENSE for more information.