Best Caching Method?

[Joseph Witchard]

I've been reviewing caching methods with .htaccess on Apache, and I'm a little confused. Some tutorials use mod_headers, while some use mod_expires, while some use both. Are any of them better than the other? And is this the same as caching by HTTP headers?

[eak]

Those two mods have different purposes, but both can achieve the same result.

http://httpd.apache.org/docs/2.0/mod/mod_headers.html
http://httpd.apache.org/docs/2.0/mod/mod_expires.html

I like the simplicity of mod_expires:
ExpiresDefault "access plus 30 days"

But with mod_headers, you have greater control over what http headers are sent.


These two mods control the headers that browsers look at for client side caching.
If you want server side caching, look into memcache (http://www.google.com/search?q=apache+memcache)

[Joseph Witchard]

Is this the same as using http headers? Same syntax and everything?

[eak]

Is what the same as using http headers?

[Joseph Witchard]

Is what the same as using http headers?

mod_headers and mod_expires.

[eak]

Yes, both of those mods will edit/append http headers when Apache sends a document.

[Joseph Witchard]

All right. Since they have "mod" in their names, am I right in assuming that they're considered part of Apache Mod_Rewrite?

[eak]

No, they are not associated with that module.
Many Apache modules use that naming convention to indicate that it is a module.

[Joseph Witchard]

Ah, okay.

Is there really a need for server-side caching if I do it on the client side? Also, is there a certain mime type for PHP files?

[eak]

Yes, server side caching has its benefits, especially for large sites.
For example, you can use memcache to store your query results in memory.
There are also modules for caching PHP opcode (APC for instance).
I read somewhere that an opcode cache will be included in PHP6.


I think the php mimetype is application/x-httpd-php. What do you need that for?
I have never need that since I primarily use php to send text/html or application/xhtml+xml.

[Joseph Witchard]

Yes, server side caching has its benefits, especially for large sites.
For example, you can use memcache to store your query results in memory.
There are also modules for caching PHP opcode (APC for instance).
I read somewhere that an opcode cache will be included in PHP6.


I think the php mimetype is application/x-httpd-php. What do you need that for?
I have never need that since I primarily use php to send text/html or application/xhtml+xml.

I don't need it. I found out that text/html works fine; I just assumed that I would need it if my files ended with .php, but I guess that's not the case. When would be a good time to use the PHP mime type, though? Could you give an example?

[eak]

One place I can think of is phps files and Apache.
AddType application/x-httpd-php-source phps

That will show syntax highlighted source code for phps files.

Using the php mime type, instead of text/html, may allow someone to download your php files. There are other ways to force downloads though (application/octet-stream, for example).