This extension emits Druid metrics to an ambari-metrics carbon server. Events are sent after been pickled (i.e., batched). The size of the batch is configurable.

Configuration

All the configuration parameters for ambari-metrics emitter are under druid.emitter.ambari-metrics.

Example druid.historical.hist-host1:8080.MyDataSourceName.GroupBy.query/time:

• druid -> namespace prefix
• historical -> service name
• hist-host1:8080 -> druid hostname
• GroupBy -> dimension value
• query/time -> metric name

We have two different implementation of event converter:

Send-All converter

White-list based converter

The second implementation called whiteList, will send only the white listed metrics and dimensions. Same as for the all converter user has control of <namespacePrefix>.[<druid service name>].[<druid hostname>]. White-list based converter comes with the following default white list map located under resources in ./src/main/resources/defaultWhiteListMap.json

Although user can override the default white list map by supplying a property called mapPath. This property is a String containing the path for the file containing white list map JSON object. For example the following converter will read the map from the file /pathPrefix/fileName.json.