Why ElasticSearch?

• Its open source
• Its hugely scaleable
• Ideal for time series data

It is part of the elasticsearch stack which can provide functionality for the following:

• Graphs (Kibana)
• Analytics (Kibana)
• Alarms

What is Covered in This article

We are going to set up a single elasticsearch node  on a Linux Ubuntu 16.04 server and use it to collect data published on a Mosquitto MQTT server.  (It assumes you already have your MQTT server up and running.)

For full information and documentation, the IoT open source stack project is now called Zibawa and has a project page of its own -where you will find source code, documentation and case studies.

Installing ElasticSearch

Create a new directory myElasticSearch

mkdir myElasticSearch
cd myElasticSearch

Download the Elasticsearch tar :

curl -L -O https://download.elastic.co/elasticsearch/release/org/elasticsearch/distribution/tar/elasticsearch/2.4.1/elasticsearch-2.4.1.tar.gz

Then extract it as follows :

tar -xvf elasticsearch-2.4.1.tar.gz

It will then create a bunch of files and folders in your current directory. We then go into the bin directory as follows:

cd elasticsearch-2.4.1/bin

And now we are ready to start our node and single cluster:

./elasticsearch

To store data we can use the command

curl -XPOST 'localhost:9200/customer/external?pretty' -d '
{
"name": "Jane Doe"
}'

To read the same data we can use

curl -XGET 'localhost:9200/customer/external/1?pretty'

If you can see the data you created, then elasticSearch is up and running!

Install the Python Client for elasticsearch

pip install elasticsearch

Install the PAHO mqtt client on the server

pip install paho-mqtt

Create a Python MQTT client script to store the MQTT data in elastic search

Use the script mqttToElasticSearch.py which uses both the MQTT Paho and ElasticSearch python libraries.  You will need to modify the lines at the top depending upon the port and IP address of your MQTT installation.

You can download the file from

https://github.com/mattfield11/mqtt-elasticSearch

Or if you have GIT installed use:

git clone https://github.com/mattfield11/mqtt-elasticSearch.git

The script should be installed into a directory on the same server as you have ElasticSearch running.

Run the Python MQTT client we just downloaded

python mqttToElasticSearch.py

To view the data we just created on elasticsearch

curl 'localhost:9200/my-index/_search?q=*&pretty'

We are now storing our MQTT data in elasticsearch!
In the next few days I will publish how to view MQTT data in Kibana where we will make graphs, and analyse the MQTT data.

Further Information

 

Zibawa – Open source from device to Dashboard.  Project, applications, documentation and source code.

https://zibawa.com

ElasticSearch

https://www.elastic.co/

Running as a service on Linux I didnt use this, but probably should have!

https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-service.html#using-systemd

 

ElasticSearch Python Client

https://www.elastic.co/guide/en/elasticsearch/client/python-api/current/index.html