DEV Community

Cover image for RethinkDB: Open Source Real-Time Database
Itachi Uchiha
Itachi Uchiha

Posted on

RethinkDB: Open Source Real-Time Database

This post published on my blog before


Hi everyone.

Today I'll talk about RethinkDB.

It's an open-source solution for a realtime database.

Whats is RethinkDB

RethinkDB is a database that is document-oriented based on NoSQL. This means we'll be using a NoSQL database system.

Where to Get It?

You can use Rethink's official website to get it.

https://rethinkdb.com/

If you're using Windows. You can use this link: https://rethinkdb.com/docs/install/windows/

Let's Start

I'll be using Windows as an OS. But it works on various systems. I extracted the rethinkdb.exe file. There is only a single file under the location below.

C:\RethinkDB
Enter fullscreen mode Exit fullscreen mode

So, I'll run this command on the terminal:

C:\RethinkDB\rethink
Enter fullscreen mode Exit fullscreen mode

RethinkDB terminal

It works!

Administration Interface

RethinkDB is coming with a built-in web-based administration interface. You can open it using this address: http://localhost:8080/

If port 8080 using by other processes, it should show an error. You can expose it to the network. If you really do that, use this flag: --bind all. When you do that, RethinkDB will be accessible on the network.

RethinkDB administration page

Dashboard

On this page, you will see some statistical information about servers, tables, indexes, etc.

The first page always will be Dashboard. The cluster performance chart is a real-time chart.

Tables

You can see your databases and tables on this page. Also, you can create databases or tables or remove them.

RethinkDB Tables

Servers

You can see your servers on this page.

RethinkDB Servers

Data Explorer

You can create your queries on this page. This is more like a playground. You don't have to use this page.

RethinkDB Data Explorer

Logs

You can see all logs here.

RethinkDB Logs

Creating a New Database

Let's go to the Tables page and click Add Database button.

RethinkDB Create Database

Its name will be ecommerce.

RethinkDB Database Name

If you're sure of your database name, click Add button.

Creating a New Table

Press the "Add Table" button in the database where you want to add a table on the same page.

RethinkDB Table Name

If you're sure of your table name, click Create table button.

It should be like that;

RethinkDB Database and Table

Insert Data

Our first example will be like that;

const r = require('rethinkdb');

const newProduct = [
  {
    productName: 'iPhone',
    productId: 1,
    amount: 1
  }
];

r.db('ecommerce').table('orders').insert(newProduct);
Enter fullscreen mode Exit fullscreen mode

You will be an output like that;

{
    "deleted": 0 ,
    "errors": 0 ,
    "generated_keys": [
        "3dbdfc12-8bba-442e-ad5b-f0827710a134"
    ],
    "inserted": 1 ,
    "replaced": 0 ,
    "skipped": 0 ,
    "unchanged": 0
}
Enter fullscreen mode Exit fullscreen mode

Select Data

If you want to get all the data in a table, use this command;

const r = require('rethinkdb');

r.db('ecommerce').table('orders');
Enter fullscreen mode Exit fullscreen mode

Filter Data

Data filtering works a little bit differently here. So, we'll use the filter method. But its behavior is different than JavaScript's filter method.

const r = require('rethinkdb');

r.db('ecommerce').table('orders').filter(r.row('productName').eq('iPhone'));
Enter fullscreen mode Exit fullscreen mode

The output fill be like that;

{
"amount": 1 ,
    "id": "3dbdfc12-8bba-442e-ad5b-f0827710a134" ,
    "productId": 1 ,
    "productName": "iPhone"
}
Enter fullscreen mode Exit fullscreen mode
  • r.row refers to the currently visited document.
  • r.row('productName') refers to the value of the field productName of the visited document.
  • The eq command returns true if two values are equal

These are ReQL commands.

Filter Data by Primary Keys

If you need to filter data by primary keys use this ReQL command;

const r = require('rethinkdb');

r
 .db('ecommerce')
 .table('orders')
 .get('3dbdfc12-8bba-442e-ad5b-f0827710a134');
Enter fullscreen mode Exit fullscreen mode

Real-Time Feeds

So let's say we'll update the basket in real-time. What should we do? I'll use RethinkDB's official Node.JS driver for this example.

You can see official drivers here: https://rethinkdb.com/docs/install-drivers/

Firstly, I'll create an empty NodeJS project and I'll install the JavaScript driver of the RethinkDB using this command;

npm install rethinkdb
Enter fullscreen mode Exit fullscreen mode

I'll create a file called index.js. We'll write some codes like that;

const r = require('rethinkdb');

const rethinkDbConnectionObject = {
    host: 'localhost',
    port: 28015
};

r.connect(rethinkDbConnectionObject, (err, conn) => {
    if (err) {
        console.error('Error:', err);
        return;
    }

    console.log('RethinkDB works');

    r.db('ecommerce').table('orders').changes().run(conn, (err, cursor) => {
        if(err) {
            console.error('Error:', err);
            return;
        }

        cursor.each((err, row) => {
            if(err) {
                console.error('Error:', err);
                return;
            }

            console.log(row)
        });
    });
});
Enter fullscreen mode Exit fullscreen mode

And run this command;

node index.js
Enter fullscreen mode Exit fullscreen mode

Now, let's back to the playground to insert data.

const newProduct = [
  {
    productName: 'Vestel',
    productId: 5111,
    amount: 2
  }
];

r.db('ecommerce').table('orders').insert(newProduct);
Enter fullscreen mode Exit fullscreen mode

Our client-side project got the new data that we inserted now in real-time. The script we started before shows this output;

RethinkDB works
{
  new_val: {
    amount: 2,
    id: '4d79cf49-e661-49c6-a74a-21d7502bd85b',
    productId: 5111,
    productName: 'Vestel'
  },
  old_val: null
}
Enter fullscreen mode Exit fullscreen mode

Let's say we want to update amounts of all orders

r.db('ecommerce').table('orders').update({ amount: 1 });
Enter fullscreen mode Exit fullscreen mode

We'll see an output like that;

{
  new_val: {
    amount: 1,
    id: '4d79cf49-e661-49c6-a74a-21d7502bd85b',
    productId: 5111,
    productName: 'Vestel'
  },
  old_val: {
    amount: 2,
    id: '4d79cf49-e661-49c6-a74a-21d7502bd85b',
    productId: 5111,
    productName: 'Vestel'
  }
}
{
  new_val: {
    amount: 1,
    id: 'b126f221-f7fd-43e8-b0b8-1ff472a08981',
    productId: 51,
    productName: 'Xaomi'
  },
  old_val: {
    amount: 6,
    id: 'b126f221-f7fd-43e8-b0b8-1ff472a08981',
    productId: 51,
    productName: 'Xaomi'
  }
}
{
  new_val: {
    amount: 1,
    id: '69507d9a-2680-478f-a68b-85fe5035744c',
    productId: 3,
    productName: 'Huawei'
  },
  old_val: {
    amount: 2,
    id: '69507d9a-2680-478f-a68b-85fe5035744c',
    productId: 3,
    productName: 'Huawei'
  }
}
{
  new_val: {
    amount: 1,
    id: 'acbac94b-2947-448c-8a43-02bb0b2fe9b8',
    productId: 2,
    productName: 'Samsung'
  },
  old_val: {
    amount: 5,
    id: 'acbac94b-2947-448c-8a43-02bb0b2fe9b8',
    productId: 2,
    productName: 'Samsung'
  }
}
Enter fullscreen mode Exit fullscreen mode

It worked as we expected :)

Conclusion

  • If you don't want to use socket.io, you can use RethinkDB.
  • It really fasts for basic projects. I didn't have a chance to try it for a big project.
  • It has good drivers for many programming languages
  • You can understand ReQL easily. Because it's JavaScript's itself

That's all. Thanks for reading.

Resources

Discussion (6)

Collapse
calexander3 profile image
Craig Alexander

If you enjoy your sanity, then I implore you to never use RethinkDB for production use. After a certain scale, behavior of maintenance tasks become unpredictable and can either cause no down time or hours.

Collapse
itachiuchiha profile image
Itachi Uchiha Author

Yes. I agree with you. Actually, it can help you with small projects.

Collapse
starpebble profile image
starpebble

Please let me tell you what I'm thinking. I am comparing this database to AWS AppSync. AppSync manages state. Possibly this is what exactly this database does.

Collapse
itachiuchiha profile image
Itachi Uchiha Author

Thanks. I didn’t use AppSync before.

This DB needs a cache size of at least 3 GB. I don’t know which one is the best solution.

Collapse
huseyinozkilic profile image
Huseyin OZKILIC

Hi friend, u wanna check the link for windows link,
there is no windows binary collection of this

download.rethinkdb.com/#browse/browse

Collapse
itachiuchiha profile image
Itachi Uchiha Author

Windows binaries locates under the raw folder.

download.rethinkdb.com/#browse/bro...