OpenTSDB Emitter
- Introduction
- Configuration
  - Druid to OpenTSDB Event Converter

OpenTSDB Emitter

To use this Apache Druid extension, include opentsdb-emitter in the extensions load list.

Introduction

This extension emits druid metrics to OpenTSDB over HTTP (Using Jersey client). And this emitter only emits service metric events to OpenTSDB (See Druid metrics for a list of metrics).

Configuration

All the configuration parameters for the OpenTSDB emitter are under druid.emitter.opentsdb.

property	description	required?	default
`druid.emitter.opentsdb.host`	The host of the OpenTSDB server.	yes	none
`druid.emitter.opentsdb.port`	The port of the OpenTSDB server.	yes	none
`druid.emitter.opentsdb.connectionTimeout`	`Jersey client` connection timeout(in milliseconds).	no	2000
`druid.emitter.opentsdb.readTimeout`	`Jersey client` read timeout(in milliseconds).	no	2000
`druid.emitter.opentsdb.flushThreshold`	Queue flushing threshold.(Events will be sent as one batch)	no	100
`druid.emitter.opentsdb.maxQueueSize`	Maximum size of the queue used to buffer events.	no	1000
`druid.emitter.opentsdb.consumeDelay`	Queue consuming delay(in milliseconds). Actually, we use `ScheduledExecutorService` to schedule consuming events, so this `consumeDelay` means the delay between the termination of one execution and the commencement of the next. If your druid processes produce metric events fast, then you should decrease this `consumeDelay` or increase the `maxQueueSize`.	no	10000
`druid.emitter.opentsdb.metricMapPath`	JSON file defining the desired metrics and dimensions for every Druid metric	no	./src/main/resources/defaultMetrics.json
`druid.emitter.opentsdb.namespacePrefix`	Optional (string) prefix for metric names, for example the default metric name `query.count` with a namespacePrefix set to `druid` would be emitted as `druid.query.count`	no	null

Druid to OpenTSDB Event Converter

The OpenTSDB emitter will send only the desired metrics and dimensions which is defined in a JSON file. If the user does not specify their own JSON file, a default file is used. All metrics are expected to be configured in the JSON file. Metrics which are not configured will be logged. Desired metrics and dimensions is organized using the following schema:<druid metric name> : [ <dimension list> ]
e.g.

"query/time": [
    "dataSource",
    "type"
]

For most use-cases, the default configuration is sufficient.