How To Set Up Subdomain or multi-domains and Apache Virtual Hosts on Ubuntu 14.04 LTS

This post is about creating multiple domains/sub-domains or virtual hosts on a single VPS running on Ubuntu 14.04 LTS with LAMP stack. (for LEMP stack, see another good example here.)

Summary

1) Create an A record for your sub-domain that points to your droplet

2) Create a .config file for your sub-domain site in /etc/apache2/sites-available

3) Create the directory for your site in /var/www (or wherever you defined it was in the config file)

4) Enable the site in apache with: sudo a2ensite sub.yourdomain.com (or whatever you named your site in the config)

5) reload apache: sudo service apache2 reload

NOTE: the DNS record you create might take awhile to propagate

Switching MySQL 5.x to MariaDB 10.x on Ubuntu 14.04

If you are going to use MariaDB to replace existing implementation of MySQL in production environment, then you will realize changing a DBMS to one another has never been easier considering the risks of incompatible supported features and functionalities, unpredictable development time and resources, migrating a huge amount of data and so on. MariaDB has already succeeded as a "drop-in" replacement  for MySQL and is truly open source and more optimized, faster and safer.

Though being mentioned that Migration might become difficult after 2015, below is a few steps which I believe is quite simple to install MariaDB replacing MySQL on Ubuntu 14.04.x as I came across the same requirement switching MySQL 5.5.5 to MariaDB 10.1.14.

Limitation for google sitemap.xml file size

According to the Latest Update: (as of 2016):

Any Sitemap file is limited to 10MB (uncompressed) with a maximum of 50,000 URLs.
And a Sitemap index file can include up to 10,000 Sitemaps.
So we can have around 50 millions URLs in separated sitemap files.

in terms of URLs:

49,000 URLs + 1,000 sitemaps
= 49,000 URLs + ( 1,000 * 50,000 ) URLs
= 50,049,000 URLs 

in terms of size:

10MB + (1,000 sitemaps * 10MB)
= 10,010 MB
= 10.01 GB 

So altogether, we can have around 10GB of storage for all sitemap files.