[TYPO3-dev] better cache management in extensions (tt_news example)

[Malte Jansen]

Hi!

This extension makes something simluar for a news-overview...

http://www.rggooglemap.com/dev/chnewssort.html

Cheers,

Malte

Krystian Szymukowicz schrieb:
> 
> hi
> 
> Today typical use of tt_news extension and cache settings:
> 
> root
>   |-- sys folder - tt_news records (id = 2) TCEMAIN.clearCacheCmd = 3,4
>   |-- standard page - tt_news LIST_VIEW (id = 3)
>   |-- standard page - tt_news SINGLE VIEW (id = 4)
> 
> 
> With every change on sys_folder (id = 2) all cache of id 3,4 are cleared.
> 
> It is not optimal.
> 
> In systems with few thousand tt_news records and average 1000ms tt_news 
> item rendering we have thousand seconds of server usage (3600s = 1h).
> 
> 
> Is seems like there is a way to clear only cache of pages that have 
> changed.
> 
> 
> FIRST STEP
> --------------------------
> Mark every occurrence of tt_news record at page (let's call it "tt_news 
> record marker"). This is simple. We can use id of the news with proper 
> word.
> 
> It is up to webdesigner how he will integrate it into his tt_news 
> template. Few possibilities:
> 
> 1) additional class in <a>
> <a href=”...” class=”designclass ttnews_cache_232”>tt news reecord 232 
> title</a>
> <a href=”...” class=”designclass ttnews_cache_212”>tt news reecord 212 
> title</a>
> 
> 2) id in <a>
> <a href=”...” class=”designclass” id=”ttnews_cache_232”>tt news reecord 
> 232 title</a>
> <a href=”...” class=”designclass” id=”ttnews_cache_212”>tt news reecord 
> 212 title</a>
> 
> 3) additional div
> <div id=”ttnews_cache_232”><a href=”...” class=”designclass” >tt news 
> reecord 232 title</a></div>
> <div id=”ttnews_cache_232”><a href=”...” class=”designclass” 
> id=”ttnews_cache_212”>tt news reecord 212 title</a></div>
> 
> 4) simple html comments after record link
> <a href=”...” class=”designclass” id=”ttnews_cache_212”>tt news reecord 
> 212 title</a><!-- ttnews_cache_232 -->
> 
> 
> SECOND STEP
> --------------------------------------
> Define what "cache_pages" to search in for "tt_news record markers".
> This id for performance issue in order not to search in all cache_pages 
> records.
> This setting is similar "TCEMAIN.clearCacheCmd = 3,4" but because 
> TCEMAIN.clearCacheCmd is not optimal in this scenario we have to define 
> that another way: For example something like:
> 
> plugin.tt_news.clearCache = 3,4
> 
> 
> 
> THIRD STEP
> --------------------------------
> A hook "after record save" will get pids from plugin.tt_news.clearCache 
> and id of tt_news that was modified and will delete from "cache_pages" 
> table all records with ttnews_cache_[id] in "HTML" field of "cache_pages".
> 
> 
> 
> Above clear cache system is good for the case the tt_news record was 
> only edited.
> If we add or delete tt_news record we have to clear LIST_VIEWS anyway 
> but do not have to clear cache of SINGLE_VIEW page (which we have to do 
> with standard TCEMAIN.clearCacheCMD).
> 
> 
> To get add/delete into account the TS settings needs to be little expanded.
> 
> Example:
> 
>    plugin.tt_news.clearCache.list_view_pids = 3
>    plugin.tt_news.clearCache.single_view_pids = 4
> 
> 
> Lets see what have to be done in different tt_news record operation.
> a) RECORD EDIT
> 
>    For "RECORD EDIT" use "tt_news record markers" search and delete in
>        plugin.tt_news.clearCache.list_view_pids
>     plugin.tt_news.clearCache.single_view_pids
> 
> 
> b) RECORD ADD/DELETE
> 
>    For "add,delete" clear all page_cache for:
>     plugin.tt_news.clearCache.list_view_pids
> 
>    AND use "tt_news record markers" for
>     plugin.tt_news.clearCache.single_view_pids
> 
>    to search for bi-directional relation of new/deleted record.
> 
> 
> 
> 
> Take into account that in both cases we didn't have to clear all 
> SINGLE_VIEW cache and in case of simple tt_news edit we delete really 
> only those pages that are needed.
> 
> 
> Although it seems to be possible I would like to have your opinion, 
> because I am not very good in TYPO3 internals and maybe there is a 
> simple misunderstanding in my idea.
> 
> 
> -- 
> grtz
> Krystian
>