TWikiGuestCacheAddOn < TWiki

---+!! TWiki Guest Cache Add-On
<!--
   Contributions to this add-on are appreciated. Please update the contrib page at
   http://twiki.org/cgi-bin/view/Plugins/TWikiGuestCacheAddOn or provide feedback at
   http://twiki.org/cgi-bin/view/Plugins/TWikiGuestCacheAddOnDev.
   If you are a TWiki contributor please update the add-on in the SVN repository.
-->
<sticky>
<div style="float:right; background-color:#EBEEF0; margin:0 0 20px 20px; padding: 0 10px 0 10px;">
%TOC{title="Page contents"}%
</div></sticky>
%SHORTDESCRIPTION%

---++ Overview

Public TWiki sites are frequently visited by search engine spiders and non-authenticated users. The actual traffic by authenticated users who browse and change content is typically less than 5% of all traffic. This add-on is designed to cache topics for non-authenticated users. Content is not cached for authenticated users - this ensures that personalized content remains personalized.

A typical TWiki page may load in about 1 second. A cached topic loads about 10 times faster.

Deploying this add-on on a public TWiki site tends to speed up the site for all users. It also reduces the CPU load considerably on a high traffic site. On TWiki.org the average CPU load dropped from 2-3 down to 0.2-0.5 after deploying this add-on.

---++ Cache Algorithm

Once the add-on is installed and configured it can be forgotten, the caching and cache update is done automatically.

A topic is only cached if:

   * the user is _not_ authenticated,
   * the requested URL has no parameters,
   * the requested topic exists,
   * the topic is not on the exclusion list.

The cached content is returned if all conditions are met and if the cache exists. If needed, a topic is cached or re-cached first.

A configurable cache invalidation determines when a topic is re-cached. There are three tiers:

   * Tier 1 topics, such as =WebChanges, !WebRss=: Cache invalidation is 1 hour by default.
   * Tier 2 topics, such as =WebHome, !WebTopicList=: Cache invalidation is 6 hours by default.
   * Other topics: Cache invalidation is 48 hours by default.

---++ Installation Instructions

__Note:__ You do not need to install anything on the browser to use this add-on. The following instructions are for the administrator who installs the add-on on the TWiki server.

   * For an __automated installation__, run the [[%SCRIPTURL{configure}%][configure]] script and follow "Find More Extensions" in the in the __Extensions__ section. 
      * See the [[http://twiki.org/cgi-bin/view/Plugins/BuildContribInstallationSupplement][installation supplement]] on TWiki.org for more information.

   * Or, follow these __manual installation__ steps: 
      * Download the ZIP file from the Plugins home (see below).
      * Unzip ==%TOPIC%.zip== in your twiki installation directory. Content:
        | *File:* | *Description:* |
        | ==data/TWiki/%TOPIC%.txt== | Add-on topic |
        | ==bin/viewcache== | View script with cache logic |
        | ==lib/TWiki/Contrib/%TOPIC%.pm== | Add-on Perl module |
        | ==lib/TWiki/Contrib/%TOPIC%/Config.spec== | Spec file for configure |
      * Set the ownership of the extracted directories and files to the webserver user.
   * Add-on __configuration and testing__:
      * Configure the <nop>%TOPIC% settings in the __Extensions__ section.
         * Settings:
           %BR% =# Comma-space delimited list of topic names to exclude:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{ExcludeTopics} = 'TWikiRegistration';=
           %BR% =# Comma-space delimited list of tier 1 topic names:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{Tier1Topics} = 'WebAtom, !WebChanges, !WebRss';=
           %BR% =# Maximum cache age for tier 1 pages, in hours:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{Tier1CacheAge} = '1';=
           %BR% =# Comma-space delimited list of tier 2 topic names:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{Tier2Topics} = 'WebHome, !WebTopicList';=
           %BR% =# Maximum cache age for tier 2 pages, in hours:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{Tier2CacheAge} = '6';=
           %BR% =# Maximum cache age for default pages, in hours:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{CacheAge} = '48';=
           %BR% =# Debug flag:=
           %BR% =$TWiki::cfg{TWikiGuestCacheAddOn}{Debug} = 0;=
      * Copy the =twiki/bin/viewcache= script to =twiki/bin/view= (overwrite the latter).
      * Test if the installation was successful:
         * Logout and view a topic as a not authenticated user.
         * On the shell, check if the cache file =twiki/pub/.cache/&lt;web&gt;/&lt;topic&gt;.html= has been created.
         * The second time you view a topic, it should load much faster.
         * Look at the tail of the TWiki log file =twiki/data/log%SERVERTIME{$year$mo}%.txt= to verify that cached content is returned you should see ="from cache"= entries. Example:%BR% =| %SERVERTIME{$year-$mo-$day - $hour:$min}% | guest | view | !Support.SupportForum | Mozilla - from cache | 1.2.3.4 |=

---++ Add-On Info

   * Set SHORTDESCRIPTION = Speed up a TWiki site by caching topics for non-authenticated users

|  Add-on Author: | TWiki:Main.PeterThoeny |
|  Copyright: | &copy; 2009-2018 TWiki:Main.PeterThoeny <br /> &copy; 2009-2018 TWiki:TWiki.TWikiContributor |
|  License: | GPL ([[http://www.gnu.org/copyleft/gpl.html][GNU General Public License]]) |
|  Add-on Version: | 2018-07-10 |
|  Change History: | <!-- versions below in reverse order --> |
|  2018-07-10: | TWikibug:Item7841: Copyright update to 2018 |
|  2016-01-13: | TWikibug:Item7708: Copyright update to 2016 |
|  2015-10-09: | TWikibug:Item7568: Typo fixes -- thanks TWiki:Main.RobertBagwill |
|  2015-04-28: | TWikibug:Item7627: Use engine->run() to initiate TWiki |
|  2015-03-20: | TWikibug:Item7627: Add configuration option to exclude topics from caching |
|  2013-10-25: | TWikibug:Item7371: Add BlogFeed to list of rss content-type pages |
|  2013-10-17: | TWikibug:Item7371: Align date format with TWiki-6.0, e.g. add seconds to log entries |
|  2013-07-01: | TWikibug:Item7154: Clean up anchor links of TOC so that no login is required when a guest clicks on a TOC link |
|  2013-02-22: | TWikibug:Item7154: Check for failed cache with zero byte content, if so, return regular TWiki page |
|  2013-02-22: | TWikibug:Item7154: Output proper content type for RSS & ATOM feeds |
|  2012-12-28: | TWikibug:Item7112: Call view script from command line, no need for wget to cache topics |
|  2012-12-22: | TWikibug:Item7094: Initial version |
|  TWiki Dependency: | $TWiki::Plugins::VERSION 1.3 (TWiki-5.0) |
|  CPAN Dependencies: | none |
|  Other Dependencies: | none |
|  Perl Version: | 5.005 |
|  Add-on Home: | http://TWiki.org/cgi-bin/view/Plugins/TWikiGuestCacheAddOn |
|  Feedback: | http://TWiki.org/cgi-bin/view/Plugins/TWikiGuestCacheAddOnDev |
|  Appraisal: | http://TWiki.org/cgi-bin/view/Plugins/TWikiGuestCacheAddOnAppraisal |

__Related Topic:__ %SYSTEMWEB%.TWikiAddOns
This topic: TWiki > TWikiGuestCacheAddOn
Topic revision: r2 - 2019-01-03 - TWikiAdminUser
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