David_18981
Nimbostratus
NimbostratusRam Cache with Include list
Hi F5 Community,
i want to share with you TWO issues i encountered with Ram Cache behaviour on Big IP devices.
These issues are related to "Include list" usage for "HTTP Ram Cache" profile.
Here is my testing environnement :
- Big IP LTM 10.2.0
- 1 VS with a custom HTTP profile (http_cache)
- 1 custom HTTP profile with Ram Cache enable
- 1 Group with 1 Node (Apache Webserver)
My Apache webserver pages tree :
- index.php (including two resources 1 JS & 1 CSS)
- objet.js
- style.css
My expectations regarding Ram Cache :
- I want Ram Cache to cache only files with extension ".js" and ".css", so in my environnement only the files "objet.js" & "style.css"
=================
1°) First issue :
=================
When i configure my "http_cache" profile as followed :
- Ramcache "Enabled"
- Maximum Cache Size "10"
- Maximum Entries "10000"
- Maximum Age "3600"
- Minimum Object Size "500" (default value)
- Maximum Object Size "50000" (default value)
- URI List Include Lise "*.js" & "*.css"
- Ignore Headers "All"
- Insert Age Header "Enabled"
- Aging Rate "9"
And then i execute the following request :
- GET /index.php
The Big IP caches the following files "index.php", "objet.js" and "styles.css"
-------------
bp>profile http http_cache ramcache entry show
PROFILE HTTP http_cache - Ramcache Entry:
+-> Host: helloworld.com URI: /index.php
....
+-> Host: helloworld.com URI: /objet.js
....
+-> Host: helloworld.com URI: /style.css
....
bp>
-------------
But when i configure RAM Cache profil as this :
- Minimum Object Size "0"
- Maximum Object Size "0"
And then execute the following request :
- GET /index.php
The Big IP caches the good files; only "objet.js" and "style.css"
-------------
bp>profile http http_cache ramcache entry show
PROFILE HTTP http_cache - Ramcache Entry:
+-> Host: helloworld.com URI: /objet.js
....
+-> Host: helloworld.com URI: /style.css
....
bp>
-------------
[CONCLUSION]
So my conclusion, to use "Include list" as a filter to cache objects, you need to configure "Minimum & Maximum object size" to 0
=================
2°) Second issue :
=================
My second issue is related to how to set "Include list".
[CONFIG 1]
In this example, i used the following Ram Cache configuration :
- Ramcache "Enabled"
- Maximum Cache Size "10"
- Maximum Entries "10000"
- Maximum Age "3600"
- Minimum Object Size "0"
- Maximum Object Size "0"
- URI List Include List "/*.js" & "/*.css"
- Ignore Headers "All"
- Insert Age Header "Enabled"
- Aging Rate "9"
If i execute the following requests :
- GET /index.php
- GET /index.php?page=js&value=john
The Big IP caches well "objet.js" and "style.css", but also "index.php?page=js&value=john" what it's not the expected behaviour.
-------------
bp>profile http http_cache ramcache entry show
PROFILE HTTP http_cache - Ramcache Entry:
+-> Host: helloworld.com URI: /index.php?page=js&value=john
....
+-> Host: helloworld.com URI: /objet.js
....
+-> Host: helloworld.com URI: /style.css
....
bp>
-------------
[CONFIG 2]
With this configuration :
- URI List Include List "/*\.js$" & "/*\.css$"
- GET /index.php
- GET /index.php?page=js&value=john
The Big IP caches well "objet.js" and "style.css", and NOT "index.php?page=js&value=john" what it's the expected behaviour.
-------------
bp>profile http http_cache ramcache entry show
PROFILE HTTP http_cache - Ramcache Entry:
+-> Host: helloworld.com URI: /objet.js
....
+-> Host: helloworld.com URI: /style.css
....
bp>
-------------
[CONFIG 3]
With this configuration :
- URI List Include List "*.js" & "*.css"
- GET /index.php
- GET /index.php?page=js&value=john
- GET /index.php?page=js&value=johnjs
The Big IP caches well "objet.js" and "style.css", and not "index.php?page=js&value=john" neither "index.php?page=js&value=johnjs" what it's the expected behaviour.
-------------
bp>profile http http_cache ramcache entry show
PROFILE HTTP http_cache - Ramcache Entry:
+-> Host: helloworld.com URI: /objet.js
....
+-> Host: helloworld.com URI: /style.css
....
bp>
-------------
[CONCLUSION]
In my conclusion, the way Big IP reads "Include list" entries is different according if it starts with "/" or not.
- When "Include list" entry starts with "/" => RegEx
- When "Include list" entry doesn't start with "/" => Pattern String (as for HTTP Class)
What do you think about my analysis ? Did you encounter these issues ?
