Apache HTTP Server - Default Cache

[gigamaster]

Apache HTTP Server

Configure default cache duration

1. Enable cache
2. Cache duration
3. Cheatsheet - conversion time
4. Mime Type
5. Multiple Mime Types
6. Example using mod_expires module
7. Example using mod_headers module

1. Enable cache

# Enable caching
ExpiresActive On

2. Cache duration

Default duration effective for all the MIME types.

# Default cache duration to 1 yr
# A31536000 stands for 1 year in the future -> 31536000 = 365 * 24 * 60 * 60

# Below listed are the examples to set 1 yr
ExpiresDefault "access plus 1 year"
ExpiresDefault "access plus 12 months"
ExpiresDefault "access plus 365 days"
ExpiresDefault A31536000

# Default cache duration to 1 month
# A2592000 stands for 30 days in the future -> 2592000 = 30 * 24 * 60 * 60

# Below listed are the examples to set 1 month
ExpiresDefault "access plus 1 month"
ExpiresDefault "access plus 4 weeks"
ExpiresDefault "access plus 30 days"
ExpiresDefault A2592000

# Default cache duration to 1 day or 1 hour
# A86400 stands for 1 day in the future -> 86400 = 24 * 60 * 60
# A3600 stands for 1 hour in the future -> 3600 = 60 * 60

# Below listed are the examples to set 1 day or 1 hour
ExpiresDefault A86400
ExpiresDefault A3600

3. Cheatsheet

Conversions from Seconds to Mins, Days, Weeks, and Months.

## Seconds  - Minutes
#      300  -  5 MINS - Example - A300
#      600  - 10 MINS
#      900  - 15 MINS
#     1800  - 30 MINS
#     2700  - 45 MINS

## Seconds  -  Hours
#     3600  -  1 HR
#    18000  -  5 HRS
#    36000  - 10 HRS
#    54000  - 15 HRS
#    86400  - 24 HRS

## Seconds  -   Days
#    86400  - 1 DAY
#   432000  - 5 DAYS

## Seconds  -   Weeks
#   604800  - 1 WEEK
#  1209600  - 2 WEEKS
#  1814400  - 3 WEEKS
#  2419200  - 4 WEEKS

## Seconds  -    Months
#  2419200  -  1 MONTH
# 12096000  -  5 MONTHS
# 24192000  - 10 MONTHS
# 29030400  - 12 MONTHS

4. Mime Type

Add an extension and cache specific MIME type

# Format - the extension is optional here
# AddType <type> <extension>

# Add MIME type to support svg extension
AddType image/svg+xml .svg

# Cache gif images for 1 year for
ExpiresByType image/gif "access plus 1 year"
ExpiresByType image/gif "access plus 12 months"
ExpiresByType image/gif "access plus 30 days"
ExpiresByType image/gif A31536000

5. Multiple Mime Types

# One month duration for selected file types
<FilesMatch "\.(ico|pdf|avi|mov|doc|mp3|wmv|wav)$">
	ExpiresDefault A2592000
</FilesMatch>

6. Example using mod_expires module

<ifModule mod_expires.c>
  # Add font and image types
  AddType application/vnd.ms-fontobject .eot
  AddType application/x-font-ttf .ttf
  AddType application/x-font-opentype .otf
  AddType application/x-font-woff .woff
  AddType image/svg+xml .svg

  # Enable caching
  ExpiresActive On

  # Default cache duration to 1 yr
  ExpiresDefault A31536000

  # Enable caching of individual image file types
  ExpiresByType image/gif A31536000
  ExpiresByType image/png A31536000
  ExpiresByType image/jpg A31536000
  ExpiresByType image/jpeg A31536000
  ExpiresByType image/x-icon A31536000
  ExpiresByType image/icon A31536000
  ExpiresByType image/svg+xml A31536000
  
  # Enable caching of text types
  ExpiresByType text/plain A31536000
  ExpiresByType text/css A31536000
  ExpiresByType text/javascript A31536000
  
  # Enable caching of individual application types
  ExpiresByType application/x-javascript A31536000
  ExpiresByType application/javascript A31536000
  ExpiresByType application/x-ico A31536000
  ExpiresByType application/ico A31536000
  ExpiresByType application/pdf A31536000
  ExpiresByType application/vnd.ms-fontobject A31536000
  ExpiresByType application/x-font-ttf A31536000
  ExpiresByType application/x-font-opentype A31536000
  ExpiresByType application/x-font-woff A31536000
</ifModule>

7. Example using mod_headers module

# One month duration for selected file types
# max-age -> 30 days ( 60 * 60 * 24 * 30 )
<FilesMatch "\.(ico|pdf|avi|mov|doc|mp3|wmv|wav)$">
	Header set Cache-Control "max-age=2592000, public"
</FilesMatch>