Concrete CMS Cluster
Concrete CMS is a free and open source content management system (CMS) designed for easy usage so even newbies with a minimal set of technical skills can work with it. You can edit the content of your site without leaving the page instead of using an administrative interface or web editors.
Within the current instruction we’ll describe not just simple way to deploy the Concrete CMS app (this can be found in the appropriate document) but a way to configure a high-available cluster for its running.
To enhance availability and reliability of the service, we are going to set up a complex solution with 2 Apache servers, 2 replicated MySQL databases, a Memcached node and NGINX load balancer.
In this case Memcached is used to backup the Apache server sessions. So if one server fails, the second will take the sessions from Memcached and perform the further serving. NGINX is going to balance the traffic inside the cluster. And replicated MySQL primary and secondary databases increase the performance, data security and the fail-over capabilities of your environment.
Let’s get started!
Create Environment and Deploy Concrete CMS
First of all, you need to create a new environment with one Apache server and one MySQL database in order to deploy the Concrete CMS application to it.
1. Log into the platform dashboard and click the Create environment button at the top panel. You will see the topology wizard opened.
2. Navigate to its PHP tab and pick up the following nodes:
- Apache application server
- MySQL database
- Memcached node
Also choose the PHP 5.3 version within the appropriate drop-down list.
3. Define the amount of cloudlets for the chosen nodes, specify the environment name (e.g. concrete) and click Create. In a minute or so your environment will appear at the dashboard.
4. Then navigate to the official Concrete CMS web-site and download its Latest Stable Version.
5. Switch back to the platform dashboard and click the Upload button at the Deployment manager panel. In the opened frame choose the received .zip archive for uploading.
6. Once the package is in the platform, click the Deploy to button next to it and choose the environment you have just created. In the opened window specify the context Concrete CMS will be deployed to (or just leave it blank) and click the Deploy button.
Congrats! You have got your application deployed. Let’s go on.
Configure Session Storage
Now let’s set up the sessions clustering in order to provide the high availability for our cluster.
1. Click the Config button for Apache node. In the opened Configuration manager navigate to the /etc/php.ini file and activate the PHP Memcached module by adding the following line:
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2. Find Session block in the same php.ini file and enable sessions support by editing the next two lines:
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Note: < server > is the Memcached IP or URL. You can find it by clicking Info button next to the Memcached node in your environment.
3. Save the changes you’ve performed and restart Apache server in order to apply new settings.
That’s it! For now, if one application server instance in a cluster fails, user’s session will be automatically picked up and served by another Apache instance.
Database Configuration
The next step is to configure the primary-secondary (master-slave) database replication, aimed to ensure the protection of data in your Concrete CMS cluster.
1. In order to set up the MySQL cluster you need to create one more environment with just single MySQL node, which will be used as a secondary database.
Wherein the role of the primary DB will belong to the MySQL server in the environment with Concrete CMS application deployed.
To configure the replication between these databases follow the detailed instructions in the MySQL/MariaDB Primary-Secondary Replication document.
2. Once you’ve adjusted the database clustering, navigate to the phpMyAdmin panel of the primary DB and create a new concrete database.
3. You can make sure that database replication is configured properly by navigating to the admin panel of your secondary MySQL server. You’ll see that the newly created and already replicated concrete DB is added to the list of databases in the appropriate tab.
Concrete CMS Installation
Now it is time to complete the installation of our Concrete CMS. Press Open in browser button next to the environment with application deployed.
You’ll be shown an installation wizard in a new tab. Its steps are rather simple. Therefore let’s pay some attention to the defining the main settings.
Fill in the following fields:
- Name Your Site: insert the desired name of your site
- Email Address: type the email of administrator user
- Password: specify the password for administrator user
- Server: paste the link to the primary database without http://
- MySQL Username: enter login you’ve received in the email with credentials to primary DB while environment creation (root by default)
- MySQL Password: type the password from the same email
- Database Name: specify the name of the database you’ve created just after configuring the DB replication (concrete in our case)
Then choose if your site will contain the sample of content or will be blank and complete the installation process.
Cluster Configuration
Finally, let’s configure the cluster itself.
1. Click the Change environment topology button for the environment with CMS deployed.
2. Increase the number of Apache application servers by pressing the corresponding button. Note that NGINX-balancer node will be automatically added to your environment. Click Apply.
In such a way all the data between application server instances will be synchronized and there is no need to perform the double installation and configuration.
3. Now you can open your Concrete CMS and start working with it.
That’s it! You’ve got your highly available and reliable Concrete CMS application up and running.