druid/docs/content/Firehose.md

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Druid Firehoses

Firehoses describe the data stream source. They are pluggable and thus the configuration schema can and will vary based on the type of the firehose.

Field Type Description Required
type String Specifies the type of firehose. Each value will have its own configuration schema, firehoses packaged with Druid are described below. yes

We describe the configuration of the Kafka firehose example, but there are other types available in Druid (see below).

  • consumerProps is a map of properties for the Kafka consumer. The JSON object is converted into a Properties object and passed along to the Kafka consumer.
  • feed is the feed that the Kafka consumer should read from.

Available Firehoses

There are several firehoses readily available in Druid, some are meant for examples, others can be used directly in a production environment.

KafkaFirehose

This firehose acts as a Kafka consumer and ingests data from Kafka.

StaticS3Firehose

This firehose ingests events from a predefined list of S3 objects.

TwitterSpritzerFirehose

See Examples. This firehose connects directly to the twitter spritzer data stream.

RandomFirehose

See Examples. This firehose creates a stream of random numbers.

RabbitMqFirehose

This firehose ingests events from a define rabbit-mq queue.

LocalFirehose

This Firehose can be used to read the data from files on local disk. It can be used for POCs to ingest data on disk. A sample local firehose spec is shown below:

{
    "type"    : "local",
    "filter"   : "*.csv",
    "baseDir"  : "/data/directory"
}
property description required?
type This should be "local". yes
filter A wildcard filter for files. See here for more information. yes
baseDir location of baseDirectory containing files to be ingested. yes

IngestSegmentFirehose

This Firehose can be used to read the data from existing druid segments. It can be used ingest existing druid segments using a new schema and change the name, dimensions, metrics, rollup, etc. of the segment. A sample ingest firehose spec is shown below -

{
    "type"    : "ingestSegment",
    "dataSource"   : "wikipedia",
    "interval" : "2013-01-01/2013-01-02"
}
property description required?
type ingestSegment. Type of firehose yes
dataSource A String defining the data source to fetch rows from, very similar to a table in a relational database yes
interval A String representing ISO-8601 Interval. This defines the time range to fetch the data over. yes
dimensions The list of dimensions to select. If left empty, no dimensions are returned. If left null or not defined, all dimensions are returned. no
metrics The list of metrics to select. If left empty, no metrics are returned. If left null or not defined, all metrics are selected. no
filter See Filters yes

CombiningFirehose

This firehose can be used to combine and merge data from a list of different firehoses. This can be used to merge data from more than one firehoses.

{
    "type"  :   "combining",
    "delegates" : [ { firehose1 }, { firehose2 }, ..... ]
}
property description required?
type combining yes
delegates list of firehoses to combine data from yes

EventReceiverFirehose

EventReceiverFirehoseFactory can be used to ingest events using http endpoint. when using this firehose druid.realtime.chathandler.type needs to be set to announce in runtime.properties.

{
  "type": "receiver",
  "serviceName": "eventReceiverServiceName",
  "bufferSize": 10000
}

when using above firehose the events can be sent via submitting a POST request to the http endpoint - http://<peonHost>:<port>/druid/worker/v1/chat/<eventReceiverServiceName>/push-events/

property description required?
type receiver yes
serviceName name used to announce the event receiver service endpoint yes
bufferSize size of buffer used by firehose to store events no default(100000)