Apache Virtual Host Config www vs non-www, Rewrite or sServerAlias?

Question

We have a central httpd.conf and we include confs for various virtual hosts. Until today, we didn't really have a need for "www.subdomain.site.com" domains, only "subdomain.site.com." Now we do, so I am trying to figure out which of these two approaches is better:

[1]. Use a Rewrite:

    RewriteCond %{HTTP_HOST} ^www.subdomain.site.com
    RewriteRule ^(.*)$ http://subdomain.site.com$1 [R=301]

OR

[2]. Use ServerAlais:

    <VirtualHost 111.22.33.44:80>
    ServerName subdomain.site.com
    ServerAlias www.subdomain.site.com
    Include conf/subdomain.conf
    </VirtualHost>

I imagine there is more processing on the Rewrite, but unsure of how ServerAlias would behave in this mix. Does one get better SEO foo than the other?

Any and all ideas welcome!

Thanks,

KM

In the rewrite, the `RewriteCond` needs to go first, and the variable should be `%{HTTP_HOST}`. — David Z, Jun 28 '10 at 20:39

score 4 · Answer 1 · answered Jun 28 '10 at 20:44

I'd imagine the rewriting solution gets better SEO-foo (nice term :-P) since it's usually considered best to have one canonical domain that everybody gets sent to for a particular set of content. In other words, having two different domains that produce the same results from the server can split your site rankings between the two domains, reducing the value of each. (Google allows you to specify a canonical domain using its Webmaster Tools, but that only works on Google)

I think you can actually use a Redirect here, i.e.

<VirtualHost *:80>
    ServerName www.subdomain.site.com
    Redirect permanent / http://subdomain.site.com/
</VirtualHost

That is less computationally intensive than invoking mod_rewrite.

Does this directive work only for the root domain or does it redirect all specific endpoints following the / as well? — armadadrive, Jan 04 '17 at 22:31
According to the [`Redirect` documentation](https://httpd.apache.org/docs/current/mod/mod_alias.html#redirect), it redirects everything beginning with the specified path, not only the root. — David Z, Jan 04 '17 at 22:35

score 2 · Accepted Answer · answered Jun 30 '10 at 15:05

I would probably do both. With something like:

<VirtualHost 111.22.33.44:80>
  ServerName subdomain.site.com

  #Using Wildcard: might as well handle any variation
  #such as ww.subdomain.site.com (remember to set this in DNS too)
  ServerAlias *.subdomain.site.com

  RewriteEngine On

  #Change all variations to the Canonical hostname for SEO.
  RewriteCond %{HTTP_HOST} !^subdomain.site.com [NC]
  RewriteRule ^/(.*)$ http://subdomain.site.com/$1 [R=301]
  Include conf/subdomain.conf 
</VirtualHost>

Note: the solution by David Zaslavsky above does more or less the same thing, but this way you don't have to do a separate VirtualHost section for each subdomain.

Dave and Matthew, thank you both for your suggestions. Between the two suggestions I have more than enough to get going in the right direction! — KM., Jul 02 '10 at 13:52

score 1 · Answer 3 · answered Aug 18 '15 at 00:56

Here's what works for me:

<VirtualHost *:80>

ServerName www.domain.com
ServerAlias domain.com

# [ snip some unrelated stuff ]

# Redirect secondary hostnames to canonical hostname
RewriteEngine On
RewriteCond %{HTTP_HOST} ^domain.com$
RewriteRule (.*) http://www.domain.com$1 [R=301,L]

</VirtualHost>

The advantage of doing this instead of RedirectMatch is that it will redirect domain.com/about-us to www.domain.com/about-us instead of just redirecting every request to the home page. It also uses a 301 redirect, which transfers search engine ranking from domain.com/about-us to www.domain.com/about-us.

Apache Virtual Host Config www vs non-www, Rewrite or sServerAlias?

3 Answers3