How to Install Crate.IO on CentOS 7

Crate.IO, or Crate, is an open source scalable document-oriented data store which combines a standard SQL interface with Elasticsearch, bringing you both the speed and ease of use of Elasticsearch and the powerful features of standard SQL.

In this tutorial, I will show you how to install Crate.IO on a CentOS 7 server.

Prerequisites

• A Vultr CentOS 7 server instance built from scratch.
• A sudo user.

Step 1: Update the system

Log in as a sudo user, run the following commands to update the system to the latest stable status:

sudo yum install epel-release -y
sudo yum update -y
sudo shutdown -r now

Step 2: Install Crate.IO

Setup the Crate.IO YUM repo:

sudo rpm --import https://cdn.crate.io/downloads/yum/RPM-GPG-KEY-crate
sudo rpm -Uvh https://cdn.crate.io/downloads/yum/7/noarch/crate-release-7.0-1.noarch.rpm

Install Crate.IO using YUM:

sudo yum install crate -y

Start the Crate.IO service:

sudo systemctl start crate.service
sudo systemctl enable crate.service

Step 3: Modify firewall rules

In order to allow outside access to Crate.IO, you need to open port 4200 in the firewall configuration:

sudo firewall-cmd --zone=public --permanent --add-port=4200/tcp
sudo firewall-cmd --reload

Step 4: Test Crate.IO

You can use the curl program to get details about Crate.IO on your server instance:

curl 127.0.0.1:4200

If nothing goes wrong, the details about Crate.IO will display on the screen as below:

{
  "ok" : true,
  "status" : 200,
  "name" : "Trick Shot",
  "cluster_name" : "crate",
  "version" : {
    "number" : "0.55.4",
    "build_hash" : "2d16cf28f96ed72624d80667c52effc8328efe76",
    "build_timestamp" : "2016-08-16T12:02:51Z",
    "build_snapshot" : false,
    "es_version" : "2.3.4",
    "lucene_version" : "5.5.0"
  }
}

Then you can visit the web interface of Crate.IO by pointing your web browser to http://<your-server-IP>:4200/admin.

In the Crate.IO administration interface, as a beginner, you can click the "Get Started" Tab to import some sample data from the Twitter stream, and then use the "Console" tab to execute queries.

Step 5: Install Crate's cli—Crash

Not only can you use Crate.IO in the graphic user interface, you can also use it in the command line interface.

You can use pip to install Crate's cli, Crash:

sudo yum install python-pip -y
sudo pip install --upgrade pip
sudo pip install --upgrade Pygments
sudo pip install crash

For example, you can use Crash to connect Crate.IO on the local machine:

crash --hosts 127.0.0.1:4200

In the Crash shell, you can perform SQL queries on the sample data imported earlier:

select * from tweets limit 5;

Finally, use the following command to quit the Crash shell:

\q

That concludes our tutorial. Thank you for reading.