Stream Satori open data feeds with Apache NiFi

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Description

Learn how to consume real-time data from the Satori RTM platform using NiFi.

Background

Satori is a cloud-based live platform that provides a publish-subscribe messaging service called RTM, and also makes available a set of free real-time data feeds as part of their Open Data Channels initiative:

https://www.satori.com/docs/using-satori/overview
https://www.satori.com/opendata/channels

This article steps through how to consume from Satori's Open Data Channels in NiFi, using a custom NiFi processor.
Note - the article assumes you already have a working version of NiFi up and running.

Link to code on github: https://github.com/laurencedaluz/nifi-satori-bundle

Installing the custom processor

To create the required nar file, simply clone and build the following repo with maven:

git clone https://github.com/laurencedaluz/nifi-satori-bundle.git
cd nifi-satori-bundle
mvn clean install

This will make the following .nar file under the nifi-satori-bundle-nar/target/ directory:

nifi-satori-bundle-nar-<version>.nar

Copy this file into the lib directory of your NiFi instance. If using HDF, it exists at:

/usr/hdf/current/nifi/lib

Restart NiFi for the nar to be loaded.

Using the ConsumeSatoriRtm processor

The ConsumeSatoriRtm accepts the following configurations:

At a minimum, you will just need to provide the following configurations (which you can get directly from the satori open channels site):

• Endpoint
• Appkey
• Channel

In this example, I've chosen to consume from the 'big-rss' feed using the configurations provided here: https://www.satori.com/opendata/channels/big-rss

That's it! after starting the ConsumeSatoriRtm process you will see data flowing:

Additional Features

• The processor also supports using Satori's Streamview filters, which allow you to provide SQL-like queries to select, transform, or aggregate messages from a subscribed channel:
  
  • In the 'big-rss' example above, the following filter configuration would limit the stream to messages containing the word "jobs".

  select * from `big-rss` where feedURL like '%jobs%'

• The NiFi processor also supports batching of multiple messages into a single FlowFile, which will provide a new-line delimited list of messages in each file (based on a 'minimum batch size' configuration):