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Administration of JotCache Plugin

Because JotCache Plugin is advanced replacement of System - Cache it is necessary to disable system cache plugin in Administration > Extensions > Plugin Manager.

Open in administrator Plugin Manager the JotCache plugin, review parameters and set their values to required operation mode. JotCache plugin has three tabs :

  • Plugin (basic settings)
  • Cache Operation Modes - selection of cache activity depending on visitor browser
  • Cache Storage - selection between server file system or memcached server

Plugin basic settings

In JotCache ver.5.1 were introduced 2 new additional parameters : Edit Page Invalidate and Domain Filter. Details are described in New features in ver.5.1

Explanation

1. Browser caching - Web server is forcing the site visitor browser to local caching of sent content.

USE with high care. Setting this parameter to 'Yes' caches all pages on user browsers with NO reloading from the site server during browser cache lifetime.

Browser Cache lifetime is set for each top URI path on component special form. Web page is local cached in browser and it remains x minutes valid (during this time browser shall not call any more the site server for page loading but the page is recalled from browser local cache). This behavior can be overridden pressing Reload button on the user browser toolbar. Then the browser calls again server for page loading.

2. Cache lifetime - Cached web page remains x minutes in page cache stored

3. Mark caching - Condition for displaying Set Mark in JotCache component. For presentation of frontend cache marking and backend check have to be both conditions met :

Plugin Mark caching=Yes
Component Set Mark=On

4. Cache Auto Clean – This function is enabled by setting of positive integer x representing number of minutes. Automatic cleaning process starts initially postponed each x minutes and it performs deleting of expired cache files from the server file system.

Cleaning activity is limited to max. 500 ms duration. Remaining expired cache items are then deleted during next user requests each time with max. 500 ms duration until all expired items are deleted from the cache.

Short overview about the cleaning process can be gained with JotCache Clean Log parameter set to Yes.

5. Autoclean Mode (Fast, Medium, Slow) – controlling autoclean behavior and usage of server memory for this task.

Autoclean takes segment of files stored in the cache and process this segment in one internal run. In Fast mode are used only several segments and processing is fast with higher usage of internal memory. With Medium or Slow setting are these segments smaller and smaller but processing is slower.

Recommended for middle sized web sites is Fast setting, for large ones you have to experiment with Medium/Slow settings.

6. Clean Log – Logging function switched On is allowing to have look into cache auto clean activity. Log is created in Joomla top directory 'logs' with the name 'plg_jotcache.autoclean.log.php'. Each cleaning run is represented with one log line in this format :

date             time        server IP        
2010-12-04 12:40:50 127.0.0.1  
interrupted on : (x|ffffffffffffffffffffffffffffffffffffffffffff) last deleted : y

where

x – represents number of last processed segment
f..f – represents name of last processed cache file
y - represents number of deleted pages

When clean run processes all items without interruption then only plain information about deleted files is stored in log. The best autoclean mode setting is with small number of interruptions taking into account reasonable internal server memory usage.

7. Cookies Split - This input box is used to distinguish pages with same URL and browser access but with different cookie values. Cookies split is allowing separate cache storage for each unique set of cookie name/value definitions.

For forcing cookies split it is necessary to set each one cookie definition per line into this input box. Cookie definition consists from following line definition :

#cookieName

After correct setting of cookies split are the active cookies which were recognized during page caching shown on component Management view :

Show cookies parameter in JotCache component Options have to be set to Yes.


8. Multisite selection - In case of multisite Joomla operation is necessary to store internal links as absolute URL. With storing absolute URL is lost easy portability (take care for cleaning entire cache after the migration) but page caching reflects true URLs on the site.

After change is done it is recommended to clean entire page cache (on JotCache Management View click on button Delete ALL).

9. URL Cache Selection - Processed frontend pages are included or excluded from caching based on this plugin parameter. Fine selection which pages are influenced is defined on JotCache component form “Include URL / Exclude URL

10. Global exclude

USE ONLY IN THE CASE WHEN JOTCACHE COMPONENT EXCLUDE IS NOT ENOUGH.

In some very rare cases can Joomla request contain 'virtual' component link which does not belongs to installed components stored in the Joomla database. In such case when you need to exclude specific links and/or pages from caching here is possibility to define parts of URL (key=value pair) which are excluded.

After saving JotCache parameters check if the JotCache plugin is enabled and located as last item in system plugins list (if it is not then correct status and items order).

Cache Operation Modes

1. Operation Mode – Many Joomla templates systems are using separate templates for different browser types (mostly Internet Explorer). With splitted cache storage space for different browser types you can avoid unacceptable mixing of unproper templates to site users (cached page content is not rendered when non-expired page exists in the cache).

For each browser category (incl. phones, tablets) is possible to select own operation mode:

  • Exclude from caching
  • Use common cache (for different browser categories)
  • Use individual cache

2. Bots exclude – If enabled then visiting crawlers (bots) shall access non-cached pages - important in some cases e.g. image lazy loading.

Cache Storage

JotCache has possibility to choose from two different cache storages :

  • server file system (default)
  • memcached server (with 2 different PHP modules operation)

Access to memcache and/or memcached PHP modules is available only if they are installed and they are accessable from Joomla.


Memcached storage for JotCache requires :

  • Memcached server (service on Windows) which usually listening on port 11211
  • PHP module memcache (lighter, oldier solution) or PHP module memcached (newer solution)

Fast check what is installed on host server can be done inside Joomla in following way :

  1. open Joomla backend System/Global Configuration/Server and open combobox Cache Handler
  2. open Joomla System/System Information/PHP Information and search for memcache or memcached module