druid/docs/development/extensions-contrib/opentsdb-emitter.md

id	title
opentsdb-emitter	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.